ASTM D7622-10
(Test Method)Standard Test Method for Total Mercury in Crude Oil Using Combustion and Direct Cold Vapor Atomic Absorption Method with Zeeman Background Correction
Standard Test Method for Total Mercury in Crude Oil Using Combustion and Direct Cold Vapor Atomic Absorption Method with Zeeman Background Correction
SIGNIFICANCE AND USE
The emission of mercury during crude oil refining is an environmental concern. The emission of mercury may also contaminate refined products and form amalgams with metals, such as aluminum.
When representative test portions are analyzed according to this procedure, the total mercury is representative of concentrations in the sample.
SCOPE
1.1 This test method covers the procedure to determine the total mercury content in a sample of crude oil. This test method can be used for total mercury determination in natural and processed liquid and oil products (gasoline, naphtha, etc.).
1.2 This test method may be applied to samples containing between 5.0 to 350 ng/mL of mercury. The results may be converted to mass basis.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 WARNINGMercury has been designated by many regulatory agencies as a hazardous material that can cause central nervous system, kidney and liver damage. Mercury, or its vapor, may be hazardous to health and corrosive to materials. Caution should be taken when handling mercury and mercury containing products. See the applicable product Material Safety Data Sheet (MSDS) for details and EPA’s websitehttp://www.epa.gov/mercury/faq.htmfor additional information. Users should be aware that selling mercury and/or mercury containing products into your state or country may be prohibited by law.
1.5 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
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D7622–10
Standard Test Method for
Total Mercury in Crude Oil Using Combustion and Direct
Cold Vapor Atomic Absorption Method with Zeeman
Background Correction
This standard is issued under the fixed designation D7622; 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 D4057 Practice for Manual Sampling of Petroleum and
Petroleum Products
1.1 This test method covers the procedure to determine the
D4175 Terminology Relating to Petroleum, Petroleum
totalmercurycontentinasampleofcrudeoil.Thistestmethod
Products, and Lubricants
can be used for total mercury determination in natural and
D4177 Practice for Automatic Sampling of Petroleum and
processed liquid and oil products (gasoline, naphtha, etc.).
Petroleum Products
1.2 This test method may be applied to samples containing
D6299 Practice for Applying Statistical Quality Assurance
between 5.0 to 350 ng/mL of mercury. The results may be
and Control Charting Techniques to Evaluate Analytical
converted to mass basis.
Measurement System Performance
1.3 The values stated in SI units are to be regarded as
D6300 Practice for Determination of Precision and Bias
standard. No other units of measurement are included in this
Data for Use in Test Methods for Petroleum Products and
standard.
Lubricants
1.4 WARNING—Mercury has been designated by many
D6792 Practice for Quality System in Petroleum Products
regulatory agencies as a hazardous material that can cause
and Lubricants Testing Laboratories
central nervous system, kidney and liver damage. Mercury, or
D7482 Practice for Sampling, Storage, and Handling of
its vapor, may be hazardous to health and corrosive to
Hydrocarbons for Mercury Analysis
materials.Cautionshouldbetakenwhenhandlingmercuryand
D7623 Test Method for Total Mercury in Crude Oil Using
mercury containing products. See the applicable product Ma-
Combustion-Gold Amalgamation and Cold Vapor Atomic
terial Safety Data Sheet (MSDS) for details and EPA’s
Absorption Method
website—http://www.epa.gov/mercury/faq.htm—for addi-
tional information. Users should be aware that selling mercury
3. Terminology
and/or mercury containing products into your state or country
3.1 For definitions of terms used in this test method, refer to
may be prohibited by law.
Terminology D4175.
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4. Summary of Test Method
responsibility of the user of this standard to establish appro-
4.1 Controlled heating following thermal decomposition of
priate safety and health practices and determine the applica-
the analysis sample in air is used to liberate mercury. The
bility of regulatory limitations prior to use.
sample is placed into the sample boat, which is inserted in the
first chamber of the atomizer, where the sample is heated at
2. Referenced Documents
controlled temperature at 300 to 500°C (depending on the
2.1 ASTM Standards:
selected operation mode). The mercury compounds are evapo-
D1193 Specification for Reagent Water
rated and partially dissociated forming elemental mercury
vapor. Mercury and all decomposition products are carried to
the second chamber of the atomizer heated to about 700 to
This test method is under the jurisdiction of ASTM Committee D02 on
750°C(mercuryreductiontakesplaceonthesurfaceofheating
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
NiCr coil, thus no catalyst is required). Mercury compounds
D02.03 on Elemental Analysis.
Current edition approved May 1, 2010. Published July 2010.
are totally dissociated, and the organic matrix of the sample is
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
burnt out. Continuously flowing air carries mercury and other
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
combustion products through absorbance analytical cell heated
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. up to 750°C positioned in the light path of double-wave cold
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D7622–10
vapor Zeeman atomic absorption spectrophotometer. The mer- 6.4 Micropipetters, one or more units of variable volume to
cury resonance line 253.65 nm is split to several components, cover a range from 10 to 250 µL, NIST traceable. Appropri-
one of those falling within the mercury absorbance line ately sized tips should also be available.
(analytical line) profile and another one lying outside (refer- 6.5 Ultrasonic Homogenizer—A bath-type ultrasonic ho-
ence line). Difference between the intensities of these com- mogenizer is used to dissociate particulate mercury and thor-
pounds is proportional to number of mercury atoms in the oughly mix the sample.
analytical cell. Absorbance peak area or peak height is a 6.6 Glassware, volumetric flasks of various capacities and
function of the mercury concentration. Class A pipettes of various capacities. All glassware must be
thoroughly cleaned with freshly prepared, 10 % nitric acid
NOTE 1—Mercury and mercury salts can be volatized at low tempera-
solution and rinsed with water. It is recommended that dedi-
tures. Precautions against inadvertent mercury loss should be taken when
cated glassware be maintained to minimize cross-
using this test method.
contamination.
5. Significance and Use
7. Sample
5.1 The emission of mercury during crude oil refining is an
environmental concern. The emission of mercury may also 7.1 Obtain the analysis sample of crude oil in accordance
contaminate refined products and form amalgams with metals, with Practice D4057 or D4177. Crude oil should be collected
such as aluminum. in a manner that ensures a representative of the bulk container
5.2 When representative test portions are analyzed accord- is obtained.
7.2 To prevent loss of mercury during storage and handling
ing to this procedure, the total mercury is representative of
concentrations in the sample. of samples, follow Practice D7482. Samples should not be
collectedinmetalcontainers.Precleaned,glassvolatileorganic
6. Apparatus
analysis (VOA) vials have been found to be suitable for this
6.1 General configuration of the instrument shall have the purpose.
following functional components: temperature controlled 7.3 Samples should be analyzed as quickly as possible after
sample heating and decomposition furnace, measuring cu- collection. Sample containers should be kept tightly capped
vettes, mercury lamp placed in strong magnetic field, polariza- and stored in a cool location.
tion modulator to separate analytical and reference lines, and
8. Reagents and Materials
detector. The following requirements are specified for all
approved instruments.
8.1 Purity of Reagents—Reagent grade chemicals shall be
used in all tests. Unless otherwise indicated, it is intended that
NOTE 2—The approval of an instrument with respect to these functions
all reagents conform to the specifications of the Committee on
is paramount to this test method, since such approval tacitly provides
Analytical Reagents of the American Chemical Society where
approval of both the materials and the procedures used with the system to
provide these functions. such specifications are available. Other grades may be used,
provided it is first ascertained that the reagent is of sufficiently
6.1.1 Zeeman Mercury Spectrometer—Atomic absorption
high purity to permit use without lessening the accuracy of the
spectrometer with Zeeman background correction, operating
determination.
with the mercury resonance absorption wavelength of
8.2 Purity of Water—Unless otherwise indicated, reference
253.7 nm.
towatershallbeunderstoodtomeanreagentwaterconforming
6.1.2 The atomizer shall have a decomposition tube, which
to Type II of Specification D1193. Water must be checked for
shall be operated at a temperature high enough to completely
potential mercury contamination before use.
decomposethesample.Thesuggestedoperatingtemperatureis
8.3 Astandard sample of mercury ions solution (concentra-
at least 600°C.
tion = 1.0 g/L).
6.1.3 The heated analytical cell shall be capable to prevent
8.4 Certified Reference Materials (CRMs)—Use Certified
mercury loses due to deposition to cold parts and to prevent
Reference Material (CRM) crude oils with mercury values for
mercury recombination with chlorine.The suggested operating
which confidence limits are issued by a recognized certifying
temperature of the analytical cell is at least 700°C.
agency such as the National Institute of Standards and Tech-
6.1.4 The system may contain a computer for controlling
nology (NIST).
the various operations of the apparatus, for recording data, and
8.5 Nitric Acid, concentrated, Trace Metal Grade or better.
for reporting results.
8.6 Combustion Reagents, activated charcoal, 30 3 50
6.2 Analytical Balance, with a sensitivity of 0.1 mg.
mesh.
6.3 Sample Boats, quartz, stainless steel, porcelain, or other
8.7 Potassium Dichromate Solution, 4 % (mass)—Place a
material as recommended and convenient size suitable for use
4 g portion of potassium dichromate in a volumetric flask
in the instrument being used.
3 4
The sole source of supply of the apparatus known to the committee at this time Reagent Chemicals, American Chemical Society Specifications, American
is Lumex model RA 195 available from Ohio Lumex Company, 9263 Ravenna Chemical Society, Washington, DC. For suggestions on the testing of reagents not
Road, Unit A-3, Twinsburg, OH 44087. If you are aware of alternative suppliers, listed by the American Chemical Society, see Analar Standards for Laboratory
please provide this information to ASTM International Headquarters. Your com- Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
ments will receive careful consideration at a meeting of the responsible technical and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
committee, which you may attend. MD.
D7622–10
(volume of 100 mL), dissolve in distilled water and dilute with 10.3 Samples boats and charcoal should also be pretreated
the distilled water up to the mark. The solution is to be stored in the muffle furnace before initial use.
in a reservoir made of dark glass with a plug stopper. Storage
10.4 Asatisfactory blank should have stable response and a
time is 3 months.
signal that corresponds to the equivalent of < 3 ng/g mercury.
8.8 Dilution Solution—Place 500 to 600 mL of distilled
water in a heat-resistant glass and pour in carefully 50 mL of
11. Calibration Procedure
concentrated nitric acid (d = 1.37 g/mL). Stir constantly while
11.1 Spread approximately 0.2 g of charcoal in the bottom
pouring in the acid. Transfer to a volumetric flask of 1000 mL
volume, add 5 mL of 4 % potassium dichromate solution and ofacooledsampleboat.Usingamicropipetterandtip,transfer
addupwithdistilledwateruptothemark.Thesolutionistobe 100 µL of the dilution solution on to a charcoal media. Place
stored in a reservoir made of dark glass with a plug stopper.
the sample boat into the furnace area and start the instrument.
Storage time is 3 months.
Repeat this step four times to obtain blank value.
8.9 All CRMs, reference crude oils, or calibrating agents
11.2 Spread approximately 0.2 g of charcoal over bottom of
shall have precision values of less than or equal to method
a cooled sample boat. Using a micropipetter and tip, transfer
repeatability. Such CRMS, reference crude oils, or calibrating
100 µL of standard solution 200 µg/L on to a charcoal media.
agents must be stable and must be mixed thoroughly before
Place the sample boat into the furnace area and start the
each use.
instrument. Repeat this step for 20 and 2000 µg/L to span the
effective range of response. Create a calibration curve by
9. Preparation of Standards
assigning the appropriate mass of mercury introduced into the
9.1 Working Standard Set—Prepare a set of standards that
instrument with the corresponding response. Follow manufac-
are appropriate to the range settings on the instrument in use.
turer’s recommendations to use available software tools that
An example of such a set follows:
automate the calculations.
9.1.1 Place 30 mL of a dilution solution in a volumetric
11.3 Periodic Calibration Verification and
flask (100 mLvolume). Then place 2 mLof a standard sample
Recalibration—In accordance with Practice D6792, analyze a
of mercury ions NIST or other standard reference material
control sample on a periodic basis. Results obtained for the
issuing bodies’ traceable standard solution (concentration =
control sample must be within established limits. If a control
1.0 g/L). Bring the contents of the volumetric flask up to the
check sample result is out of control, all results obtained since
markwiththedilutionsolutionandstirthoroughly.Thisresults
the last successful control check must be rejected and the
inamercuryconcentrationof20mg/L( ).Thesolutionmaybe
calibration procedure repeated.
stored in a refrigerator during 6 months.
9.1.2 Place 30 mL of a dilution solution in a volumetric
flask(100mLvolume).Thenplace10mLofastandardsample 12. Procedure
of mercury solution = 20 mg/L. Bring the contents of the
12.1 Place crude oil sample containers in an ultrasonic
retort up to the mark with the dilution solution and stir
homogenizer for approximately fifteen minutes just prior to
thoroughly.This makes a 2 mg/L= 2000 µg/L( ).The solution
analysis. Keep the water in the bath at ambient temperature by
may be stored in a refrigerator during 3 months.
adding a few ice chips as the temperature rises. The homog-
9.1.3 Place 30 mL of a dilution solution in a volumetric
enization step dissociates particulate mercury and promotes a
flask(100mLvolume).Thenplace10mLofastandardsample
more stable suspension.
of mercury solution = 2.0 mg/L. Bring the contents of the
12.2 Remove sample boat and reagents (if required) from
retort up to the mark with the dilution solution and stir
muffle furnace and allow to cool to room temperature in a
thoroughly. This makes a 200 µg/L ( ). The solution may be
stored in a refrigerator during 3 months. covered container.
9.1.4 Place 30 mL of a dilution solution in a volumetric
12.3 Spread approximately 0.2 g of charcoal over the
flask(100mLvolume).Thenplace10mLofastandardsample
bottom of a cooled sample boat.
of mercury solution = 200 µg/L.) Bring the contents of the
12.4 Shake the sample to mix
...
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