ASTM D5673-16

Standard Test Method for Elements in Water by Inductively Coupled Plasma—Mass Spectrometry

SIGNIFICANCE AND USE
5.1 The test method is useful for the determination of element concentrations in many natural waters, metallurgical process cyanide solutions and wastewaters. It has the capability for the determination of up to 21 elements. High analysis sensitivity can be achieved for some elements that are difficult to determine by other techniques.
SCOPE
1.1 This test method covers the determination of dissolved elements in ground water, surface water, and drinking water. It may also be used for the determination of total-recoverable elements in these waters as well as wastewater.2  
1.2 This test method should be used by analysts experienced in the use of inductively coupled plasma—mass spectrometry (ICP-MS), the interpretation of spectral and matrix interferences and procedures for their correction.  
1.3 It is the user's responsibility to ensure the validity of the test method for waters of untested matrices.  
1.4 Table 1 lists elements for which the test method applies, with recommended masses and typical estimated instrumental detection limits using conventional pneumatic nebulization. Actual working detection limits are sample dependent and, as the sample matrix varies, these detection limits may also vary. In time, other elements may be added as more information becomes available and as required. (A) Instrument detection limits (3σ) estimated from seven replicate scans of the blank (1 % v/v HNO3) and three replicate integrations of a multi-element standard.  
1.4.1 This method covers the analysis of mine dewatering groundwater and wastewater effluent in the range of 2–120 μg/L dissolved antimony and 3–200 μg/L dissolved arsenic.  
1.4.2 This method covers the analysis of metallurgical processing cyanide solutions in the range of 1–500 µg/L dissolved gold.  
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Published
• Publication Date: 31-Jan-2016
• ICS: 13.060.50 - Examination of water for chemical substances
• Technical Committee: D19 - Water
• Drafting Committee: D19.05 - Inorganic Constituents in Water

Relations

• Refers: ASTM D1129-13(2020)e2 - Standard Terminology Relating to Water
• Effective Date: 01-May-2020
• Refers: ASTM E1601-19 - Standard Practice for Conducting an Interlaboratory Study to Evaluate the Performance of an Analytical Method
• Effective Date: 01-Nov-2019
• Refers: ASTM D1066-18e1 - Standard Practice for Sampling Steam
• Effective Date: 01-Aug-2018
• Refers: ASTM D1066-18 - Standard Practice for Sampling Steam
• Effective Date: 01-Aug-2018
• Refers: ASTM E691-13 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-May-2013
• Refers: ASTM E1601-12 - Standard Practice for Conducting an Interlaboratory Study to Evaluate the Performance of an Analytical Method
• Effective Date: 15-Dec-2012
• Refers: ASTM D2777-12 - Standard Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
• Effective Date: 15-Jun-2012
• Refers: ASTM E691-11 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-Nov-2011
• Refers: ASTM D1066-11 - Standard Practice for Sampling Steam
• Effective Date: 15-Jun-2011
• Refers: ASTM D5810-96(2011) - Standard Guide for Spiking into Aqueous Samples
• Effective Date: 01-May-2011
• Refers: ASTM D3370-10 - Standard Practices for Sampling Water from Closed Conduits
• Effective Date: 01-Dec-2010
• Refers: ASTM E1601-10 - Standard Practice for Conducting an Interlaboratory Study to Evaluate the Performance of an Analytical Method
• Effective Date: 15-May-2010
• Refers: ASTM D1129-10 - Standard Terminology Relating to Water
• Effective Date: 01-Mar-2010
• Refers: ASTM D3370-08 - Standard Practices for Sampling Water from Closed Conduits
• Effective Date: 01-Oct-2008
• Refers: ASTM E691-08 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-Oct-2008

Overview

ASTM D5673-16 is the Standard Test Method for Elements in Water by Inductively Coupled Plasma–Mass Spectrometry (ICP-MS). Published by ASTM International, this standard outlines procedures for determining dissolved and total-recoverable concentrations of up to 21 elements in ground water, surface water, drinking water, wastewaters, and metallurgical process cyanide solutions.

ICP-MS is recognized for its high sensitivity and multi-element capability, making this standard essential for laboratories analyzing environmental and industrial water samples to detect trace metals and other elements efficiently.

Key Topics

• Scope of Method:

  • Applicable to the analysis of dissolved elements in ground water, surface water, and drinking water
  • Suitable for both dissolved and total-recoverable elements in water and wastewater matrices
  • Can be used to analyze mine dewatering flows and metallurgical processing cyanide solutions

• Analytical Capability:

  • Supports determination of up to 21 elements such as antimony, arsenic, gold, cadmium, lead, selenium, uranium, and zinc
  • Enables detection of low trace levels with high sensitivity that are challenging for other techniques

• Sample Preparation and Preservation:

  • Samples should be filtered (if needed) and acid-preserved to pH 2 with nitric acid
  • Guidance on handling cyanide-containing samples and use of lab-grade reagents and water

• Calibration and Quality Control:

  • Emphasizes the use of internal standards and calibration blanks
  • Details requirements for instrument calibration, standard preparation, and regular verification using certified reference solutions
  • Specifies ongoing quality control, including blanks and check samples, to ensure accuracy and reproducibility

• Interference and Correction Procedures:

  • Addresses potential spectral and matrix interferences typical of ICP-MS
  • Describes methods for correcting isobaric, polyatomic ion, and physical interferences

Applications

ASTM D5673-16 is widely used in:

• Environmental Monitoring: Routine assessment of drinking water, rivers, lakes, and groundwater for regulatory compliance and public health.
• Wastewater Analysis: Testing effluent from industrial facilities, municipalities, and mine dewatering operations for metal content.
• Metallurgical and Industrial Processes: Analysis of process solutions, including cyanide solutions for gold determination.
• Research and Laboratory Quality Assurance: Supports environmental studies, method validation, and interlaboratory comparisons.
• Regulatory Compliance: Meets requirements for trace elements analysis set by authorities such as the US EPA and other international bodies.

The method's reliable detection limits and robust correction procedures make it invaluable for situations where regulatory limits for metals in water are stringent or background concentrations are low.

Related Standards

• EPA Method 200.8: Determination of Trace Elements in Waters and Wastes by ICP-MS
• ASTM D1129: Terminology Relating to Water
• ASTM D1193: Specification for Reagent Water
• ASTM D2777: Practice for Determination of Precision and Bias of Water Test Methods
• ASTM D3370: Practices for Sampling Water from Closed Conduits
• ASTM D5810: Guide for Spiking into Aqueous Samples
• ASTM D5847: Practice for Writing Quality Control Specifications for Water Analysis

For laboratories focused on water quality analysis and trace element determination, ASTM D5673-16 is a foundational standard that ensures data comparability, regulatory acceptance, and scientific rigor.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D5673 − 16
Standard Test Method for
Elements in Water by Inductively Coupled Plasma—Mass
Spectrometry
This standard is issued under the fixed designation D5673; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* 2. Referenced Documents
2.1 ASTM Standards:
1.1 This test method covers the determination of dissolved
elements in ground water, surface water, and drinking water. It D1066Practice for Sampling Steam
D1129Terminology Relating to Water
may also be used for the determination of total-recoverable
elements in these waters as well as wastewater. D1193Specification for Reagent Water
D2777Practice for Determination of Precision and Bias of
1.2 Thistestmethodshouldbeusedbyanalystsexperienced
Applicable Test Methods of Committee D19 on Water
in the use of inductively coupled plasma—mass spectrometry
D3370Practices for Sampling Water from Closed Conduits
(ICP-MS), the interpretation of spectral and matrix interfer-
D5810Guide for Spiking into Aqueous Samples
ences and procedures for their correction.
D5847Practice for Writing Quality Control Specifications
1.3 Itistheuser’sresponsibilitytoensurethevalidityofthe
for Standard Test Methods for Water Analysis
test method for waters of untested matrices.
E691Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
1.4 Table1listselementsforwhichthetestmethodapplies,
E1601Practice for Conducting an Interlaboratory Study to
with recommended masses and typical estimated instrumental
Evaluate the Performance of an Analytical Method
detection limits using conventional pneumatic nebulization.
E1763Guide for Interpretation and Use of Results from
Actual working detection limits are sample dependent and, as
the sample matrix varies, these detection limits may also vary. Interlaboratory Testing of Chemical Analysis Methods
(Withdrawn 2015)
In time, other elements may be added as more information
becomes available and as required.
3. Terminology
1.4.1 This method covers the analysis of mine dewatering
groundwater and wastewater effluent in the range of 2–120
3.1 Definitions:
µg/L dissolved antimony and 3–200 µg/L dissolved arsenic.
3.1.1 For definitions of terms used in this standard, refer to
1.4.2 This method covers the analysis of metallurgical Terminology D1129.
processing cyanide solutions in the range of 1–500 µg/L
3.2 Definitions of Terms Specific to This Standard:
dissolved gold.
3.2.1 calibration blank, n—a volume of water containing
the same acid matrix as is in the calibration standards (see
1.5 The values stated in SI units are to be regarded as
11.1).
standard. No other units of measurement are included in this
standard. 3.2.2 calibration standards, n—a series of known standard
solutions used by the analyst for calibration of the instrument
1.6 This standard does not purport to address all of the
(that is, preparation of the analytical curve) (see Section 11).
safety concerns, if any, associated with its use. It is the
3.2.3 calibration stock solution, n—a solution prepared
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- from the stock standard solution(s) to verify the instrument
bility of regulatory limitations prior to use. response with respect to analyte concentration.
3.2.4 dissolved, adj—capable of passing through a 0.45-µm
membrane filter.
This test method is under the jurisdiction ofASTM Committee D19 on Water
and is the direct responsibility of Subcommittee D19.05 on Inorganic Constituents
in Water. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Feb. 1, 2016. Published June 2016. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1996. Last previous edition approved in 2015 as D5673–15. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D5673-16. the ASTM website.
2 4
EPATest Method: Determination of Trace Elements in Waters and Wastes by The last approved version of this historical standard is referenced on
Inductively Coupled Plasma—Mass Spectrometry, Method200.8. www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5673 − 16
A
TABLE 1 Recommended Analytical Mass and Estimated TABLE 2 Preparation of Metal Stock Solutions
Instrument Detection Limits
Element or Weight,
Solvent
Compound g
Recommended Estimated Instrument
Element
A
Analytical Mass Detection Limit, µg/L Al 0.1000 10 mL of HCl (sp gr 1.19) + 2 mL of HNO (sp gr
1.42)
Aluminum 27 0.05
Sb 0.1000 0.5 mL of HCl (sp gr 1.19) + 2 mL of HNO
Antimony 121 0.08
(1+1)
Arsenic 75 0.9
As O 0.1320 1 mL of NH OH (sp gr 0.902) + 50 mL of H O
2 3 4 2
Barium 137 0.5
BaCO 0.1437 2 mL of HNO (spgr1.42)+10mLofH O
3 3 2
Beryllium 9 0.1
BeSO ·4H O 1.9650 50 mL of H O, add 1 mL of HNO (sp gr 1.42)
4 2 2 3
Cadmium 111 0.1
Bi O 0.1115 5 mL of HNO (sp gr 1.42)
2 3 3
Chromium 52 0.07
Cd 0.1000 5 mL of HNO (1+1)
Cobalt 59 0.03
CrO 0.1923 1 mL of HNO (sp1.42)+10mLH O
3 3 2
Copper 63 0.03
Co 0.1000 5 mL of HNO (1+1)
Gold 197 0.01
Cu 0.1000 5 mL of HNO (1+1)
Lead 206, 207, 208 0.08
Au 0.1000 20 mL H O, ad 8 mL of HCL = 5 mL HNO
2 3
Manganese 55 0.1
(1+1)
Molybdenum 98 0.1
In 0.1000 10 mL of HNO (1+1)
Nickel 60 0.2
PbNO 0.1599 5 mL of HNO (1+1)
3 3
Selenium 82 5.0
MgO 0.1658 10 mL of HNO (1+1)
Silver 107 0.05
Mn 0.1000 5 mL of HNO (1+1)
Thallium 205 0.09
MoO 0.1500 1 mL of NH OH (sp gr 0.902) + 10 mL of H O
3 4 2
Thorium 232 0.03
Ni 0.1000 5 mL of HNO (sp gr 1.42)
Uranium 238 0.02
Sc O 0.1534 5 mL of HNO (1+1)
2 3 3
Vanadium 51 0.02
SeO 0.1405 20 mL of H O
2 2
Zinc 66 0.2
Ag 0.1000 5 mL of HNO (1+1)
A
Instrument detection limits (3σ) estimated from seven replicate scans of the blank
Tb O 0.1176 5 mL of HNO (sp gr 1.42)
4 7 3
(1 % v/v HNO ) and three replicate integrations of a multi-element standard.
TlNO 0.1303 1 mL of HNO (spgr1.42)+10mLofH O
3 3 2
Th(NO ) ·4H O 0.2380 20 mL of H O
3 4 2 2
UO (NO ) ·6HO0.2110 20mLofH O
2 3 2 2 2
V 0.1000 5 mL of HNO (1+1)
Y O 0.1270 5 mL of HNO (1+1)
2 3 3
Zn 0.1000 5 mL of HNO (1+1)
A
3.2.5 interference check sample A (ICSA), n—a solution Metal stock solutions, 1.00 mL = 1000 µg of metal. Dissolve the listed weights of
each metal or compound as specified in Table 2, then dilute to 100 mL with water.
containing matrix elements at environmental levels that result
The metals may require heat to increase rate of dissolution. Commercially
in interferences on target low level analytes.
available standards of known purity may be used. Alternate salts or oxides may
also be used.
3.2.5.1 Discussion—ICSA is different from the mixed ele-
ment standards in 8.5, which are intended for instrument
calibration, not for checking interferences. The interferences
formed in the ICP can be corrected for by use of element-
3.2.11 reagent blank, n—a volume of water containing the
specific correction equations, collision cell technology with
same matrix as the calibration standards, carried through the
quadrupole-based ICP-MS, or high-resolution ICP-MS.
entire analytical procedure.
3.2.6 interference check sample B (ICSAB), n—the ICSA
3.2.12 stock standard solution, n—a concentrated solution
solution spiked with 20 µg/L each As and Sb.
containing one or more analytes, obtained as a certified
solution from a reputable source or prepared as described in
3.2.7 instrumental detection limit (IDL), n—the concentra-
Table 2.
tion equivalent to a signal, that is equal to three times the
standarddeviationoftheblanksignalattheselectedanalytical
3.2.13 total-recoverable, adj—determinable by the diges-
mass(es).
tion method included in this procedure (see 12.2).
3.2.8 internal standard, n—pureelement(s)addedinknown
3.2.14 tuning solution, n—a solution that is used to deter-
amount(s) to a solution.
mine acceptable instrument performance prior to calibration
3.2.8.1 Discussion—The internal standard is used to mea-
and sample analysis.
sure the instrument response relative to the other analytes that
3.3 Acronyms:
are components of the same solution. The internal standards
3.3.1 ICSA, n—interference check sample A
must be elements that are not a sample component.
3.3.2 ICSAB, n—interference check sample B
3.2.9 method detection limit (MDL), n—the minimum ana-
3.3.3 IDL, n—instrumental detection limit
lyteconcentrationthatcanbeidentified,measuredandreported
3.3.4 MDL, n—method detection limit
with 99 % confidence that the analyte concentration is greater
than zero.
3.3.5 QCS, n—quality-control reference solution
3.2.9.1 Discussion—This confidence level is determined
from analysis of a sample in a given matrix containing the 4. Summary of Test Method
analyte(s).
4.1 This test method describes the multi-element determi-
3.2.10 quality control reference solution (QCS), n—a solu- nation of trace elements by inductively coupled plasma—mass
tionwiththecertifiedconcentration(s)oftheanalytes,prepared spectrometry (ICP-MS). Sample material in solution is intro-
byanindependentlaboratory,andusedforaverificationofthe ducedbypneumaticnebulizationintoaradiofrequencyplasma
instrument’s calibration. where energy transfer processes cause desolvation,
D5673 − 16
TABLE 3 Recommended Analytical Isotopes and Additional
atomization, and ionization. The ions are extracted from the
Masses That Are Recommended To Be Monitored
plasma through a differentially pumped vacuum interface and
A
Isotope Element of Interest
separated on the basis of their mass-to-charge ratio by a
27 Aluminum
quadrupole mass spectrometer. The ions transmitted through
121, 123 Antimony
the quadrupole are detected by a continuous dynode electron
75 Arsenic
multiplier assembly and the ion information processed by a
135, 137 Barium
9 Beryllium
data handling system. Interferences relating to the technique
106, 108, 111, 114 Cadmium
must be recognized and corrected for (see Section 6 on
52, 53 Chromium
interferences).Suchcorrectionsmustincludecompensationfor
59 Cobalt
63, 65 Copper
isobaric elemental interferences and interferences from poly-
206, 207, 208 Lead
atomic ions derived from the plasma gas, reagents, or sample
55 Manganese
matrix. Instrumental drift as well as suppressions or enhance- 95, 97,98 Molybdenum
60, 62 Nickel
ments of instrument response caused by the sample matrix
77, 82 Selenium
must be corrected for by the use of internal standardization.
107, 109 Silver
203, 205 Thallium
5. Significance and Use
232 Thorium
238 Uranium
5.1 The test method is useful for the determination of
51 Vanadium
element concentrations in many natural waters, metallurgical 66, 67, 68 Zinc
83 Krypton
processcyanidesolutionsandwastewaters.Ithasthecapability
99 Ruthenium
for the determination of up to 21 elements. High analysis
105 Palladium
sensitivity can be achieved for some elements that are difficult
118 Tin
A
to determine by other techniques.
Isotopes recommended for analytical determination are underlined. These
masses were recommended and are reflected in the precision and bias data.
6. Interferences Alternate masses may be used but interferences must be documented.
6.1 Several types of interference effects may contribute to
inaccuracies in the determination of trace elements. These
interferences can be summarized as follows: thanoneatomthathavethesamenominalmass-to-chargeratio
6.1.1 Isobaric Elemental Interferences—Isobaric elemental as the isotope of interest, and which cannot be resolved by the
interferences are caused by isotopes of different elements mass spectrometer in use.These ions are commonly formed in
whichformsinglyordoublychargedionsofthesamenominal the plasma or interface system from support gases or sample
mass-to-chargeratioandwhichcannotberesolvedbythemass components. Most of the common interferences have been
spectrometer in use by ICP-MS. All elements determined by identified, and these are listed in Table 4 together with the
this test method have, at a minimum, one isotope free of method elements affected. Such interferences must be
isobaric elemental interference. Of the analytical isotopes recognized, and when they cannot be avoided by the selection
recommended for use with this test method (see Table 3), only of an alternative analytical isotope, appropriate corrections
molybdenum-98 (ruthenium) and selenium-82 (krypton) have must be made to the data. Equations for the correction of data
isobaric elemental interferences. If alternative analytical iso- shouldbeestablishedatthetimeoftheanalyticalrunsequence
topes having higher natural abundance are selected in order to asthepolyatomicioninterferenceswillbehighlydependenton
achieve greater sensitivity, an isobaric interference may occur. the sample matrix and chosen instrument conditions.
All data obtained under such conditions must be corrected by 6.1.4 Physical Interferences—Physical interferences are as-
measuring the signal from another isotope of the interfering sociated with the physical processes that govern the transport
element and subtracting the appropriate signal ratio from the of the sample into the plasma, sample conversion processes in
the plasma, and the transmission of ions through the plasma—
isotope of interest. A record of this correction process should
be included with the report of the data. It should be noted that mass spectrometer interface. These interferences may result in
differences between instrument responses for the sample and
suchcorrectionswillonlybeasaccurateastheaccuracyofthe
isotope ratio used in the elemental equation for data calcula- the calibration standards. Physical interferences may occur in
tions. Relevant isotope ratios and instrument bias factors the transfer of solution to the nebulizer (for example, viscosity
should be established prior to the application of any correc- effects), at the point of aerosol formation and transport to the
tions. plasma(forexample,surfacetension),orduringexcitationand
6.1.2 Abundance Sensitivity—Abundance sensitivity is a ionization processes within the plasma itself. High levels of
propertydefiningthedegreetowhichthewingsofamasspeak dissolved solids in the sample may contribute deposits of
contribute to adjacent masses. The abundance sensitivity is materialontheextraction,orskimmercones,orboth,reducing
affected by ion energy and quadrupole operating pressure. the effective diameter of the orifices and, therefore, ion
Wing overlap interferences may result when a small ion peak transmission. Dissolved solids levels not exceeding 0.2%
is being measured adjacent to a large one. The potential for (w/v) have been recommended to reduce such effects. Internal
these interferences should be recognized and the spectrometer standardization may be effectively used to compensate for
resolution adjusted to minimize them. many physical interference effects. Internal standards should
6.1.3 Isobaric Polyatomic Ion Interferences—Isobaric poly- have similar analytical behavior to the elements being deter-
atomic ion interferences are caused by ions consisting of more mined.
D5673 − 16
TABLE 4 Common Molecular Ion Interferences
cones, and from the buildup of sample material in the plasma
Background Molecular Ions torch and spray chamber. The site where these effects occur is
A
Molecular Ion Mass Element Interference dependentontheelementandcanbeminimizedbyflushingthe
+
NH 15 . system with a rinse blank consisting of HNO (1+49) in water
+
OH 17 .
between samples. The possibility of memory interferences
+
OH 18 .
+ shouldberecognizedwithinananalyticalrunandsuitablerinse
C 24 .
+
CN 26 . timesshouldbeusedtoreducethem.Therinsetimesnecessary
+
CO 28 .
for a particular element should be estimated prior to analysis.
+
N 28 .
+ This may be achieved by aspirating a standard containing
N H 29 .
+
NO 30 .
elementscorrespondingtotentimestheupperendofthelinear
+
NOH 31 .
range for a normal sample analysis period, followed by
+
O 32 .
+
analysisoftherinseblankatdesignatedintervals.Thelengthof
O H 33 .
36 +
ArH 37 . timerequiredtoreduceanalytesignalstowithinafactoroften
36 +
ArH 39 .
of the method detection limit should be noted. Memory
40 +
ArH 41 .
+ interferences may also be assessed within an analytical run by
CO 44 .
+
CO H 45 Sc using a minimum of three replicate integrations for data
+ +
ArC ,ArO 52 Cr
acquisition. If the integrated signal values drop consecutively,
+
ArN 54 Cr
+ the analyst should be alerted to the possibility of a memory
ArNH 55 Mn
+
ArO 56 .
effect, and should examine the analyte concentration in the
+
ArOH 57 .
previous sample to identify if this was high. If a memory
40 36 +
Ar Ar 76 Se
40 38 +
interference is suspected, the sample should be re-analyzed
Ar Ar 78 Se
40 +
Ar 80 Se
after a long rinse period.
118 16 +
Ta O 197 Au
Matrix Molecular Ions
7. Apparatus
Chloride
35 +
ClO 51 V
7.1 Block Digester, Hot Plate or Steam Bath—Suitable for
35 +
ClOH 52 Cr
reducingacidifiedsamplevolumefrom103mLtolessthan25
37 +
ClO 53 Cr
37 +
mL.
ClOH 54 Cr
35 +
Ar Cl 75 As
7.1.1 Block digester systems typically consist of either a
37 +
Ar Cl 77 Se
metalorgraphiteblockwithwellstoholddigestiontubes.The
Sulphate
32 +
block temperature controller must be able to maintain unifor-
SO 48 .
32 +
SOH 49 .
mity of temperature across all positions of the block.
34 +
SO 50 V, Cr
34 +
SOH 51 V 7.2 Block Digester Tubes,125-mLcapacity—Fortracemet-
+ +
SO ,S 64 Zn
2 2
als analysis, the digestion tubes should be constructed of
32 +
Ar S 72 .
34 + polypropylene and have a volume accuracy of at least 0.5 %.
Ar S 74 .
Phosphate
All lots of tubes should come with a certificate of analysis to
+
PO 47 .
demonstrate suitability for their intended purpose.
+
POH 48 .
+
PO 63 Cu
2 7.3 Inductively Coupled Plasma–Mass Spectrometer—
+
ArP 71 .
Instrument capable of measuring the mass range 5 to 250 amu
Group I, II Metals
+
with a minimum resolution capability of 1 amu peak width at
ArNa 63 Cu
+
ArK 79 .
5% peak height. Instrument may be fitted with a conventional
+
ArCa 80 .
or extended dynamic range detection system. See manufactur-
B
Matrix Oxides
ers’ instruction manual for installation and operation.
TiO 62 to 66 Ni, Cu, Zn
ZrO 106 to 112 Ag, Cd
7.4 Membrane Filter Assembly—Aborosilicate glass, stain-
MoO 108 to 116 Cd
lesssteel,orplasticfunnelwithaflat,fritted,orgridbasesoas
A
Method elements or internal standards affected by molecular ions.
B
to provide uniform support and filterable surface. The top
Oxide interferences will normally be very small and will only impact the method
elements when present at relatively high concentrations. Some examples of matrix
section of the funnel shall fit over the edge of the filter to
oxides are listed of which the analyst should be aware. It is recommended that Ti
provide a seal. The top should be removable to allow easy
and Zr isotopes be monitored if samples are likely to contain high levels of these
elements. Mo is monitored as a method analyte. access for removing the filter.AGooch crucible with a fritted
bottom may be used in lieu of the funnel.
8. Reagents and Materials
6.1.5 Memory Interferences—Memory interferences result
when isotopes of elements in a previous sample contribute to 8.1 Purity of Reagents—Reagent grade chemicals shall be
the signals measured in a new sample. Memory effects can used in all tests. Unless otherwise indicated, it is intended that
result from sample deposition on the sampler and skimmer reagents shall conform to the specifications of the committee
D5673 − 16
TABLE 5 Internal Standards and Limitations of Use
to be analyzed separately to determine possible interferences
Internal Standard Mass Possible Limitation on the other analytes or the presence of impurities. Care needs
Lithium 6 May be present in samples to be taken when preparing the mixed standard solutions to
A
Scandium 45 Polyatomic ion interference
ensure that the elements are compatible and stable.
A
Yttrium 89 May be present in samples
Rhodium 103 .
NOTE 1—Mixed calibration standards will vary, depending on the
A
Indium 115 Isobaric interference by Sn
number of elements being determined. Commercially prepared mixed
A
Terbium 159 .
calibration standards of appropriate quality may be used. An example of
Holmium 165 .
mixed calibration standards for 20 elements is as follows:
Lutetium 175 .
Platinum 195 May be present in samples Mixed Standard Solution I Mixed Standard Solution II
A
Bismuth 209 May be present in samples
Aluminum Manganese Barium
Antimony Molybdenum Silver
A
Internal standards recommended for use with this test method. It is also
Arsenic Nickel
recommended when analyzing a new sample matrix that a scan for the presence
Beryllium Selenium
of internal standards be performed.
Cadmium Thallium
Chromium Thorium
Cobalt Uranium
Copper Vanadium
on analytical reagents of the American Chemical Society,
Lead Zinc
where such specifications are available.The high sensitivity of
Prepare multi-element mixed standard solutions I and II (1
inductively coupled plasma—mass spectrometry may require
mL=10µg)bypipetting1.00mLofeachsingleelementstock
reagentsofhigherpurity.Stockstandardsolutionsareprepared
solution (see Table 2) onto a 100 mLvolumetric flask and any
from high-purity metals, oxides, or non-hydroscopic reagent
internal standards. Add 50 mL of HNO (1+99) and dilute to
grade salts using Type I, II, or III reagent water and ultrapure
100 mL with HNO (1+99). The ICSA, which is used as an
acids.
interference check, is different from the mixed element
standards, which are used for instrument calibration.
8.2 Purity of Water—Unless otherwise indicated, reference
towatershallbeunderstoodtomeanreagentwaterconforming
8.10 Nitric Acid (sp gr 1.42)—Concentrated nitric acid
to ASTM Type I water (Specification D1193). Other reagent
(HNO3), ultrapure or equivalent.
watertypesmaybeusedprovideditisfirstascertainedthatthe
8.11 Nitric Acid (1+1)—Add one volume of nitric acid (sp
water is of sufficiently high purity to permit its use without
gr 1.42) to 1 volume of water.
adversely affecting the bias and precision of the test method.
8.12 Nitric Acid (1+49)—Add one volume of nitric acid (sp
8.3 Ammonium Hydroxide (sp gr 0.902)—Concentrated am-
gr 1.42) to 49 volumes of water.
monium hydroxide (NH4OH), ultrapure or equivalent.
8.13 Nitric Acid (1+99)—Add one volume of nitric acid (sp
8.4 Argon—High purity grade (99.99%).
gr 1.42) to 99 volumes of water.
8.5 Filter Membranes—Acid washed or high purity, so that
8.14 Stock Solutions—Preparation procedures for stock so-
metal content does not contribute significantly to the reagent
lutions of each element are listed in Table 2.
blank, 0.45 µm porosity.
8.15 Reagent Blank—This solution must contain all the
8.6 Hydrochloric Acid (sp gr 1.19)—Concentrated hydro-
reagents and be the same volume as used in the processing of
chloric acid (HCl), ultrapure or equivalent.
the samples and any internal standards. Carry reagent blank
8.7 Hydrochloric Acid (1+1)—Add one volume of hydro-
through the complete procedure. Reagent blank must contain
chloric acid (sp gr 1.19) to 1 volume of water.
the same acid concentration in the final solution as the sample
solution used for analysis.
8.8 Internal Standards—Internal standards are recom-
mended in all analyses to correct for instrument drift and
8.16 Stock Solutions—Preparation procedures for stock so-
physicalinterferences.Alistofacceptableinternalstandardsis
lutions of each element are listed in Table 2.
provided in Table 5. For full mass range scans use a minimum
9. Hazards
of three internal standards with the use of five suggested.Add
internal standards to blanks, samples and standards in a like
9.1 The toxicity or carcinogenicity of each reagent used in
manner.Aconcentration of 100 µg/Lof each internal standard
this test method has not been precisely defined; however, each
is recommended.
chemical should be treated as a potential health hazard.
8.9 Mixed and
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D5673 − 15 D5673 − 16
Standard Test Method for
Elements in Water by Inductively Coupled Plasma—Mass
Spectrometry
This standard is issued under the fixed designation D5673; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope*
1.1 This test method covers the determination of dissolved elements in ground water, surface water, and drinking water. It may
also be used for the determination of total-recoverable elements in these waters as well as wastewater.
1.2 This test method should be used by analysts experienced in the use of inductively coupled plasma—mass spectrometry
(ICP-MS), the interpretation of spectral and matrix interferences and procedures for their correction.
1.3 It is the user’s responsibility to ensure the validity of the test method for waters of untested matrices.
1.4 Table 1 lists elements for which the test method applies, with recommended masses and typical estimated instrumental
detection limits using conventional pneumatic nebulization. Actual working detection limits are sample dependent and, as the
sample matrix varies, these detection limits may also vary. In time, other elements may be added as more information becomes
available and as required.
1.4.1 This method covers the analysis of mine dewatering groundwater and wastewater effluent in the range of 2–120 μg/L
dissolved antimony and 3–200 μg/L dissolved arsenic.
1.4.2 This method covers the analysis of metallurgical processing cyanide solutions in the range of 1–500 μg/L dissolved gold.
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
This test method is under the jurisdiction of ASTM Committee D19 on Water and is the direct responsibility of Subcommittee D19.05 on Inorganic Constituents in Water.
Current edition approved July 1, 2015Feb. 1, 2016. Published August 2015June 2016. Originally approved in 1996. Last previous edition approved in 20102015 as
D5673 – 10.D5673 – 15. DOI: 10.1520/D5673-15.10.1520/D5673-16.
EPA Test Method: Determination of Trace Elements in Waters and Wastes by Inductively Coupled Plasma—Mass Spectrometry, Method 200.8.
TABLE 1 Recommended Analytical Mass and Estimated
Instrument Detection Limits
Recommended Estimated Instrument
Element
A
Analytical Mass Detection Limit, μg/L
Aluminum 27 0.05
Antimony 121 0.08
Arsenic 75 0.9
Barium 137 0.5
Beryllium 9 0.1
Cadmium 111 0.1
Chromium 52 0.07
Cobalt 59 0.03
Copper 63 0.03
Gold 197 0.01
Lead 206, 207, 208 0.08
Manganese 55 0.1
Molybdenum 98 0.1
Nickel 60 0.2
Selenium 82 5.0
Silver 107 0.05
Thallium 205 0.09
Thorium 232 0.03
Uranium 238 0.02
Vanadium 51 0.02
Zinc 66 0.2
A
Instrument detection limits (3σ) estimated from seven replicate scans of the blank
(1 % v/v HNO ) and three replicate integrations of a multi-element standard.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5673 − 16
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
D1066 Practice for Sampling Steam
D1129 Terminology Relating to Water
D1193 Specification for Reagent Water
D2777 Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
D3370 Practices for Sampling Water from Closed Conduits
D5810 Guide for Spiking into Aqueous Samples
D5847 Practice for Writing Quality Control Specifications for Standard Test Methods for Water Analysis
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
E1601 Practice for Conducting an Interlaboratory Study to Evaluate the Performance of an Analytical Method
E1763 Guide for Interpretation and Use of Results from Interlaboratory Testing of Chemical Analysis Methods (Withdrawn
2015)
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms used in this standard, refer to Terminology D1129.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 calibration blank, n—a volume of water containing the same acid matrix as is in the calibration standards (see 11.1).
3.2.2 calibration standards, n—a series of known standard solutions used by the analyst for calibration of the instrument (that
is, preparation of the analytical curve) (see Section 11).
3.2.3 calibration stock solution, n—a solution prepared from the stock standard solution(s) to verify the instrument response
with respect to analyte concentration.
3.2.4 dissolved, adj—capable of passing through a 0.45-μm membrane filter.
3.2.5 interference check sample A (ICSA), n—a solution containing matrix elements at environmental levels that result in
interferences on target low level analytes.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
3.2.5.1 Discussion—
ICSA is different from the mixed element standards in 8.48.5, which are intended for instrument calibration, not for checking
interferences. The interferences formed in the ICP can be corrected for by use of element-specific correction equations, collision
cell technology with quadrupole-based ICP-MS, or high-resolution ICP-MS.
3.2.6 interference check sample B (ICSAB), n—the ICSA solution spiked with 20 μg/L each As and Sb.
3.2.7 instrumental detection limit (IDL), n—the concentration equivalent to a signal, that is equal to three times the standard
deviation of the blank signal at the selected analytical mass(es).
3.2.8 internal standard, n—pure element(s) added in known amount(s) to a solution.
3.2.8.1 Discussion—
The internal standard is used to measure the instrument response relative to the other analytes that are components of the same
solution. The internal standards must be elements that are not a sample component.
3.2.9 method detection limit (MDL), n—the minimum analyte concentration that can be identified, measured and reported with
99 % confidence that the analyte concentration is greater than zero.
3.2.9.1 Discussion—
This confidence level is determined from analysis of a sample in a given matrix containing the analyte(s).
D5673 − 16
TABLE 23 Recommended Analytical Isotopes and Additional
Masses That Are Recommended To Be Monitored
A
Isotope Element of Interest
27 Aluminum
121, 123 Antimony
75 Arsenic
135, 137 Barium
9 Beryllium
106, 108, 111, 114 Cadmium
52, 53 Chromium
59 Cobalt
63, 65 Copper
206, 207, 208 Lead
55 Manganese
95, 97,98 Molybdenum
60, 62 Nickel
77, 82 Selenium
107, 109 Silver
203, 205 Thallium
232 Thorium
238 Uranium
51 Vanadium
66, 67, 68 Zinc
83 Krypton
99 Ruthenium
105 Palladium
118 Tin
A
Isotopes recommended for analytical determination are underlined. These
masses were recommended and are reflected in the precision and bias data.
Alternate masses may be used but interferences must be documented.
3.2.10 quality control reference solution (QCS), n—a solution with the certified concentration(s) of the analytes, prepared by
an independent laboratory, and used for a verification of the instrument’s calibration.
3.2.11 reagent blank, n—a volume of water containing the same matrix as the calibration standards, carried through the entire
analytical procedure.
3.2.12 stock standard solution, n—a concentrated solution containing one or more analytes, obtained as a certified solution from
a reputable source or prepared as described in Table 42.
3.2.13 total-recoverable, adj—determinable by the digestion method included in this procedure (see 12.2).
3.2.14 tuning solution, n—a solution that is used to determine acceptable instrument performance prior to calibration and sample
analysis.
3.3 Acronyms:
3.3.1 ICSA, n—interference check sample A
3.3.2 ICSAB, n—interference check sample B
3.3.3 IDL, n—instrumental detection limit
3.3.4 MDL, n—method detection limit
3.3.5 QCS, n—quality-control reference solution
4. Summary of Test Method
4.1 This test method describes the multi-element determination of trace elements by inductively coupled plasma—mass
spectrometry (ICP-MS). Sample material in solution is introduced by pneumatic nebulization into a radiofrequency plasma where
energy transfer processes cause desolvation, atomization, and ionization. The ions are extracted from the plasma through a
differentially pumped vacuum interface and separated on the basis of their mass-to-charge ratio by a quadrupole mass spectrometer.
The ions transmitted through the quadrupole are detected by a continuous dynode electron multiplier assembly and the ion
information processed by a data handling system. Interferences relating to the technique must be recognized and corrected for (see
Section 6 on interferences). Such corrections must include compensation for isobaric elemental interferences and interferences
from polyatomic ions derived from the plasma gas, reagents, or sample matrix. Instrumental drift as well as suppressions or
enhancements of instrument response caused by the sample matrix must be corrected for by the use of internal standardization.
5. Significance and Use
5.1 The test method is useful for the determination of element concentrations in many natural waters, metallurgical process
cyanide solutions and wastewaters. It has the capability for the determination of up to 21 elements. High analysis sensitivity can
be achieved for some elements that are difficult to determine by other techniques.
D5673 − 16
TABLE 34 Common Molecular Ion Interferences
Background Molecular Ions
A
Molecular Ion Mass Element Interference
+
NH 15 .
+
OH 17 .
+
OH 18 .
+
C 24 .
+
CN 26 .
+
CO 28 .
+
N 28 .
+
N H 29 .
+
NO 30 .
+
NOH 31 .
+
O 32 .
+
O H 33 .
36 +
ArH 37 .
36 +
ArH 39 .
40 +
ArH 41 .
+
CO 44 .
+
CO H 45 Sc
+ +
ArC , ArO 52 Cr
+
ArN 54 Cr
+
ArNH 55 Mn
+
ArO 56 .
+
ArOH 57 .
40 36 +
Ar Ar 76 Se
40 38 +
Ar Ar 78 Se
40 +
Ar 80 Se
118 16 +
Ta O 197 Au
Matrix Molecular Ions
Chloride
35 +
ClO 51 V
35 +
ClOH 52 Cr
37 +
ClO 53 Cr
37 +
ClOH 54 Cr
35 +
Ar Cl 75 As
37 +
Ar Cl 77 Se
Sulphate
32 +
SO 48 .
32 +
SOH 49 .
34 +
SO 50 V, Cr
34 +
SOH 51 V
+ +
SO , S 64 Zn
2 2
32 +
Ar S 72 .
34 +
Ar S 74 .
Phosphate
+
PO 47 .
+
POH 48 .
+
PO 63 Cu
+
ArP 71 .
Group I, II Metals
+
ArNa 63 Cu
+
ArK 79 .
+
ArCa 80 .
B
Matrix Oxides
TiO 62 to 66 Ni, Cu, Zn
ZrO 106 to 112 Ag, Cd
MoO 108 to 116 Cd
A
Method elements or internal standards affected by molecular ions.
B
Oxide interferences will normally be very small and will only impact the method
elements when present at relatively high concentrations. Some examples of matrix
oxides are listed of which the analyst should be aware. It is recommended that Ti
and Zr isotopes be monitored if samples are likely to contain high levels of these
elements. Mo is monitored as a method analyte.
6. Interferences
6.1 Several types of interference effects may contribute to inaccuracies in the determination of trace elements. These
interferences can be summarized as follows:
6.1.1 Isobaric Elemental Interferences—Isobaric elemental interferences are caused by isotopes of different elements which
form singly or doubly charged ions of the same nominal mass-to-charge ratio and which cannot be resolved by the mass
spectrometer in use by ICP-MS. All elements determined by this test method have, at a minimum, one isotope free of isobaric
elemental interference. Of the analytical isotopes recommended for use with this test method (see Table 23), only molybdenum-98
D5673 − 16
A
TABLE 42 Preparation of Metal Stock Solutions
Element or Weight,
Solvent
Compound g
Al 0.1000 10 mL of HCl (sp gr 1.19) + 2 mL of HNO (sp gr
1.42)
Sb 0.1000 0.5 mL of HCl (sp gr 1.19) + 2 mL of HNO
(1 + 1)
As O 0.1320 1 mL of NH OH (sp gr 0.902) + 50 mL of H O
2 3 4 2
BaCO 0.1437 2 mL of HNO (sp gr 1.42) + 10 mL of H O
3 3 2
BeSO ·4H O 1.9650 50 mL of H O, add 1 mL of HNO (sp gr 1.42)
4 2 2 3
Bi O 0.1115 5 mL of HNO (sp gr 1.42)
2 3 3
Cd 0.1000 5 mL of HNO (1 + 1)
CrO 0.1923 1 mL of HNO (sp 1.42) + 10 mL H O
3 3 2
Co 0.1000 5 mL of HNO (1 + 1)
Cu 0.1000 5 mL of HNO (1 + 1)
Au 0.1000 20 mL H O, ad 8 mL of HCL = 5 mL HNO
2 3
(1 + 1)
In 0.1000 10 mL of HNO (1 + 1)
PbNO 0.1599 5 mL of HNO (1 + 1)
3 3
MgO 0.1658 10 mL of HNO (1 + 1)
Mn 0.1000 5 mL of HNO (1 + 1)
MoO 0.1500 1 mL of NH OH (sp gr 0.902) + 10 mL of H O
3 4 2
Ni 0.1000 5 mL of HNO (sp gr 1.42)
Sc O 0.1534 5 mL of HNO (1 + 1)
2 3 3
SeO 0.1405 20 mL of H O
2 2
Ag 0.1000 5 mL of HNO (1 + 1)
Tb O 0.1176 5 mL of HNO (sp gr 1.42)
4 7 3
TlNO 0.1303 1 mL of HNO (sp gr 1.42) + 10 mL of H O
3 3 2
Th(NO ) ·4H O 0.2380 20 mL of H O
3 4 2 2
UO (NO ) ·6H O 0.2110 20 mL of H O
2 3 2 2 2
V 0.1000 5 mL of HNO (1 + 1)
Y O 0.1270 5 mL of HNO (1 + 1)
2 3 3
Zn 0.1000 5 mL of HNO (1 + 1)
A
Metal stock solutions, 1.00 mL = 1000 μg of metal. Dissolve the listed weights of
each metal or compound as specified in Table 42, then dilute to 100 mL with water.
The metals may require heat to increase rate of dissolution. Commercially
available standards of known purity may be used. Alternate salts or oxides may
also be used.
(ruthenium) and selenium-82 (krypton) have isobaric elemental interferences. If alternative analytical isotopes having higher
natural abundance are selected in order to achieve greater sensitivity, an isobaric interference may occur. All data obtained under
such conditions must be corrected by measuring the signal from another isotope of the interfering element and subtracting the
appropriate signal ratio from the isotope of interest. A record of this correction process should be included with the report of the
data. It should be noted that such corrections will only be as accurate as the accuracy of the isotope ratio used in the elemental
equation for data calculations. Relevant isotope ratios and instrument bias factors should be established prior to the application of
any corrections.
6.1.2 Abundance Sensitivity—Abundance sensitivity is a property defining the degree to which the wings of a mass peak
contribute to adjacent masses. The abundance sensitivity is affected by ion energy and quadrupole operating pressure. Wing overlap
interferences may result when a small ion peak is being measured adjacent to a large one. The potential for these interferences
should be recognized and the spectrometer resolution adjusted to minimize them.
6.1.3 Isobaric Polyatomic Ion Interferences—Isobaric polyatomic ion interferences are caused by ions consisting of more than
one atom that have the same nominal mass-to-charge ratio as the isotope of interest, and which cannot be resolved by the mass
spectrometer in use. These ions are commonly formed in the plasma or interface system from support gases or sample components.
Most of the common interferences have been identified, and these are listed in Table 34 together with the method elements affected.
Such interferences must be recognized, and when they cannot be avoided by the selection of an alternative analytical isotope,
appropriate corrections must be made to the data. Equations for the correction of data should be established at the time of the
analytical run sequence as the polyatomic ion interferences will be highly dependent on the sample matrix and chosen instrument
conditions.
6.1.4 Physical Interferences—Physical interferences are associated with the physical processes that govern the transport of the
sample into the plasma, sample conversion processes in the plasma, and the transmission of ions through the plasma—mass
spectrometer interface. These interferences may result in differences between instrument responses for the sample and the
calibration standards. Physical interferences may occur in the transfer of solution to the nebulizer (for example, viscosity effects),
at the point of aerosol formation and transport to the plasma (for example, surface tension), or during excitation and ionization
processes within the plasma itself. High levels of dissolved solids in the sample may contribute deposits of material on the
extraction, or skimmer cones, or both, reducing the effective diameter of the orifices and, therefore, ion transmission. Dissolved
D5673 − 16
solids levels not exceeding 0.2 % (w/v) have been recommended to reduce such effects. Internal standardization may be effectively
used to compensate for many physical interference effects. Internal standards should have similar analytical behavior to the
elements being determined.
6.1.5 Memory Interferences—Memory interferences result when isotopes of elements in a previous sample contribute to the
signals measured in a new sample. Memory effects can result from sample deposition on the sampler and skimmer cones, and from
the buildup of sample material in the plasma torch and spray chamber. The site where these effects occur is dependent on the
element and can be minimized by flushing the system with a rinse blank consisting of HNO (1+49) in water between samples.
The possibility of memory interferences should be recognized within an analytical run and suitable rinse times should be used to
reduce them. The rinse times necessary for a particular element should be estimated prior to analysis. This may be achieved by
aspirating a standard containing elements corresponding to ten times the upper end of the linear range for a normal sample analysis
period, followed by analysis of the rinse blank at designated intervals. The length of time required to reduce analyte signals to
within a factor of ten of the method detection limit should be noted. Memory interferences may also be assessed within an
analytical run by using a minimum of three replicate integrations for data acquisition. If the integrated signal values drop
consecutively, the analyst should be alerted to the possibility of a memory effect, and should examine the analyte concentration
in the previous sample to identify if this was high. If a memory interference is suspected, the sample should be re-analyzed after
a long rinse period.
7. Apparatus
7.1 Block Digester, Hot Plate or Steam Bath—Suitable for reducing acidified sample volume from 103 mL to less than 25 mL.
7.1.1 Block digester systems typically consist of either a metal or graphite block with wells to hold digestion tubes. The block
temperature controller must be able to maintain uniformity of temperature across all positions of the block.
7.2 Block Digester Tubes, 125-mL capacity—For trace metals analysis, the digestion tubes should be constructed of
polypropylene and have a volume accuracy of at least 0.5 %. All lots of tubes should come with a certificate of analysis to
demonstrate suitability for their intended purpose.
7.3 Inductively Coupled Plasma–Mass Spectrometer—Instrument capable of measuring the mass range 5 to 250 amu with a
minimum resolution capability of 1 amu peak width at 5 % peak height. Instrument may be fitted with a conventional or extended
dynamic range detection system. See manufacturers’ instruction manual for installation and operation.
7.4 Membrane Filter Assembly—A borosilicate glass, stainless steel, or plastic funnel with a flat, fritted, or grid base so as to
provide uniform support and filterable surface. The top section of the funnel shall fit over the edge of the filter to provide a seal.
The top should be removable to allow easy access for removing the filter. A Gooch crucible with a fritted bottom may be used in
lieu of the funnel.
8. Reagents and Materials
8.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that
reagents shall conform to the specifications of the committee on analytical reagents of the American Chemical Society, where
such specifications are available. The high sensitivity of inductively coupled plasma—mass spectrometry may require reagents of
higher purity. Stock standard solutions are prepared from high-purity metals, oxides, or non-hydroscopic reagent grade salts using
Type I, II, or III reagent water and ultrapure acids.
8.2 Purity of Water—Unless otherwise indicated, reference to water shall be understood to mean reagent water conforming to
ASTM Type I water (Specification D1193). Other reagent water types may be used provided it is first ascertained that the water
is of sufficiently high purity to permit its use without adversely affecting the bias and precision of the test method.
8.3 Ammonium Hydroxide (sp gr 0.902)—Concentrated ammonium hydroxide (NH4OH), ultrapure or equivalent.
8.4 Argon—High purity grade (99.99 %).
8.5 Filter Membranes—Acid washed or high purity, so that metal content does not contribute significantly to the reagent blank,
0.45 μm porosity.
8.6 Hydrochloric Acid (sp gr 1.19)—Concentrated hydrochloric acid (HCl), ultrapure or equivalent.
8.7 Hydrochloric Acid (1+1)—Add one volume of hydrochloric acid (sp gr 1.19) to 1 volume of water.
8.8 Internal Standards—Internal standards are recommended in all analyses to correct for instrument drift and physical
interferences. A list of acceptable internal standards is provided in Table 5. For full mass range scans use a minimum of three
internal standards with the use of five suggested. Add internal standards to blanks, samples and standards in a like manner. A
concentration of 100 μg/L of each internal standard is recommended.
Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed by
the American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National
Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville, MD.
D5673 − 16
TABLE 5 Internal Standards and Limitations of Use
Internal Standard Mass Possible Limitation
Lithium 6 May be present in samples
A
Scandium 45 Polyatomic ion interference
A
Yttrium 89 May be present in samples
Rhodium 103 .
A
Indium 115 Isobaric interference by Sn
A
Terbium 159 .
Holmium 165 .
Lutetium 175 .
Platinum 195 May be present in samples
A
Bismuth 209 May be present in samples
A
Internal standards recommended for use with this test method. It is also
recommended when analyzing a new sample matrix that a scan for the presence
of internal standards be performed.
8.9 Mixed and Single Standard Solutions—Prepare mixed standard solutions by combining appropriate volumes of the stock
solutions in volumetric flasks (see Note 1). Prior to preparing mixed standard solutions, each stock solution needs to be analyzed
separately to determine possible interferences on the other analytes or the presence of impurities. Care needs to be taken when
preparing the mixed standard solutions to ensure that the elements are compatible and stable.
NOTE 1—Mixed calibration standards will vary, depending on the number of elements being determined. Commercially prepared mixed calibration
standards of appropriate quality may be used. An example of mixed calibration standards for 20 elements is as follows:
Mixed Standard Solution I Mixed Standard Solution II
Aluminum Manganese Barium
Antimony Molybdenum Silver
Arsenic Nickel
Beryllium Selenium
Cadmium Thallium
Chromium Thorium
Cobalt Uranium
Copper Vanadium
Lead Zinc
Prepare multi-element mixed standard solutions I and II (1 mL = 10 μg) by pipetting 1.00 mL of each single element stock
solution (see Table 42) onto a 100 mL volumetric flask and any internal standards. Add 50 mL of HNO (1+99) and dilute to 100
mL with HNO (1 + 99). The ICSA, which is used as an interference check, is different from the mixed element standards, which
are used for instrument calibration.
8.10 Nitric Acid (sp gr 1.42)—Concentrated nitric acid (HNO3), ultrapure or equivalent.
8.11 Nitric Acid (1+1)—Add one volume of nitric acid (sp gr 1.42) to 1 volume of water.
8.12 Nitric Acid (1+49)—Add one volume of nitric acid (sp gr 1.42) to 49 volumes of water.
8.13 Nitric Acid (1+99)—Add one volume of nitric acid (sp gr 1.42) to 99 volumes of water.
8.14 Stock Solutions—Preparation procedures for stock solutions of each element are listed in Table 2.
8.15 Reagent Blank—This solution must contain all the reagents
...