ASTM D6021-96(2001)e1
(Test Method)Standard Test Method for Measurement of Total Hydrogen Sulfide in Residual Fuels by Multiple Headspace Extraction and Sulfur Specific Detection
Standard Test Method for Measurement of Total Hydrogen Sulfide in Residual Fuels by Multiple Headspace Extraction and Sulfur Specific Detection
SCOPE
1.1 This test method covers a method suitable for measuring the total amount of hydrogen sulfide (H2S) in heavy distillates, heavy distillate/residual fuel blends, or residual fuels as defined in Specification D396 Grade 4, 5 (Light), 5 (Heavy), and 6, when the H2S concentration in the fuel is in the 0.01 to 100 g/g (ppmw) range.
1.2 The values stated in SI units are to be regarded as the standard.
1.3 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.For specific hazard statements, see 5.1, 7.5, 8.2, 9.2, 10.1.4, and 11.1.
General Information
Relations
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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
An American National Standard
e1
Designation: D 6021 – 96 (Reapproved 2001)
Standard Test Method for
Measurement of Total Hydrogen Sulfide in Residual Fuels
by Multiple Headspace Extraction and Sulfur Specific
Detection
This standard is issued under the fixed designation D6021; 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 (e) indicates an editorial change since the last revision or reapproval.
e NOTE—Warning notes were placed in the text editorially in May 2001.
1. Scope D5504 Test Method for the Determination of Sulfur Com-
pounds in Natural Gas and Gaseous Fuels by Gas Chro-
1.1 Thistestmethodcoversamethodsuitableformeasuring
matography and Chemiluminescence Detection
thetotalamountofhydrogensulfide(H S)inheavydistillates,
D5705 Test Method for Measurement of Hydrogen Sulfide
heavydistillate/residualfuelblends,orresidualfuelsasdefined
in the Vapor Phase Above Residual Fuel Oils
in Specification D396 Grade 4, 5 (Light), 5 (Heavy), and 6,
when the H S concentration in the fuel is in the 0.01 to 100
3. Terminology
µg/g (ppmw) range.
3.1 Definitions:
1.2 The values stated in SI units are to be regarded as the
3.1.1 heavy distillate, n—a fuel produced from the distilla-
standard.
tion of crude oil which has a kinematic viscosity at 40°C
1.3 This standard does not purport to address all of the
between 5.5 and 24.0 mm /s, inclusive.
safety concerns, if any, associated with its use. It is the
3.1.2 heavy distillate/residual fuel blend, n—a blend of
responsibility of the user of this standard to establish appro-
heavy distillate and residual fuel oil having a viscosity at 40°C
priate safety and health practices and determine the applica-
between 5.5 and 24.0 mm /s, inclusive.
bility of regulatory limitations prior to use. For specific hazard
3.1.3 multiple headspace extraction, n—a technique to de-
statements, see 5.1, 7.5, 8.2, 9.2, 10.1.4, and 11.1.
termine the total concentration of a gas trapped in a liquid by
2. Referenced Documents analysis of successive gas extractions from the vapor space of
a closed vessel containing a known amount of the sample.
2.1 ASTM Standards:
3.1.4 residual fuel oil, n—any liquid or liquefiable petro-
D396 Specification for Fuel Oils
3 leum product having a kinematic viscosity at 100°C between
D1193 Specification for Reagent Water
5.0 and 50.0 mm /s, inclusive, burned for the generation of
D2420 Test Method for Hydrogen Sulfide in Liquefied
2 heatinafurnaceorfireboxorforthegenerationofpowerinan
Petroleum (LP) Gases (Lead Acetate Method)
engine.
D3609 Practice for Calibration Techniques Using Perme-
ation Tubes
4. Summary of Test Method
D4057 Practice for Manual Sampling of Petroleum and
5 4.1 A representative sample of residual fuel oil is obtained
Petroleum Products
in sufficient quantity to completely fill the sample container.
D4084 Test Method for Analysis of Hydrogen Sulfide in
The sample is taken to the laboratory preferably within one to
Gaseous Fuels (Lead Acetate Reaction Rate Method)
4h,within24hmaximumandplacedinarefrigeratoruntilthe
D4323 Test Method for Hydrogen Sulfide in the Atmo-
hydrogen sulfide analysis can be run.At that time, the sample
sphere by Rate of Change of Reflectance
is removed from the refrigerator and allowed to sit at ambient
temperature until it flows freely.
This test method is under the jurisdiction of ASTM Committee D02 on 4.2 A 0.05 to 5.0 g test specimen (aliquot) is placed in a
PetroleumProductsandLubricantsandisthedirectresponsibilityofSubcommittee
headspacevialandheatedinanovenat60°Cformorethanfive
D02.E0.01 on Burner Fuels.
but less than 15 min. The headspace gas is sampled and
Current edition approved Dec. 10, 1996. Published February 1997.
injected into either of two types of apparatus capable of
Annual Book of ASTM Standards, Vol 05.01.
Annual Book of ASTM Standards, Vol 11.01.
Annual Book of ASTM Standards, Vol 11.03.
Annual Book of ASTM Standards, Vol 05.02.
6 7
Annual Book of ASTM Standards, Vol 05.06. Annual Book of ASTM Standards, Vol 05.03.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
e1
D 6021 – 96 (2001)
any measurement method only provides an H S concentration at a given
measuring the hydrogen sulfide concentration in the gaseous
moment in time.
sample. The two types of apparatus are those using the
reaction of lead acetate with H S (see Test Method D4084 or
6. Apparatus
Test Method D4323) and those based on chemiluminescence
6.1 A schematic of the headspace sampling system re-
(see Test Method D5504).
quired for this analysis is shown in Fig. 1. It consists of:
4.3 Theremainingcontentsoftheheadspacevialarecooled
6.1.1 Sampling On/Off Valve, with 3.2 mm o.d. connector
for 5 min, then again heated in the oven. The headspace
(Valve 1).
contents are again transferred to the hydrogen sulfide measur-
6.1.2 Six-Port External Loop Injection Valve, made with
inginstrument.Theprocedureisrepeatedforathirdtime.This
316stainlesssteel,resistanttoattackbysulfurcompoundsand
is known as multiple headspace extraction procedure (MHE).
having 3.2 mm o.d. tubing from each port (Valve 2).
4.4 Alinearplotofthenaturallogarithmoftheareaorpeak
6.1.3 Polytetrafluoroethylene (PTFE) Sample Loops, of 0.5,
height difference of the instrument reading against the number
2.5,and10mLareusedforH Scontentof1to100,0.1to50,
of injections is indicative of the correctness of the extraction
and 0.01 to 10 ppmw, respectively.
procedure.Thedifferenceinareaorpeakheightofthefirsttwo
6.1.4 Pressure/Vacuum Gage, 6.3 mm diameter dial type
injections is used to calculate a total area or total peak height
withrangeof−100to200kPag,5kPadivisionsfrom−100to
difference. The total area or total peak height difference is
0 and 10 kPa divisions from 0 to 200 kPag.
multiplied by a response factor determined from a direct gas
6.1.5 Vacuum On/Off Valve, 3.2 mm o.d. connector (Valve
calibration mixture and divided by the weight of the test
3).
specimentodeterminetheconcentrationofH Sintheresidual
6.1.6 Sulfur Selective Detector, any H S specific detector
fuel in µg/g (ppmw).
capable of measuring H S in the gas from 1 to 10000 ppmv
with a repeatability of 62% of full scale.
5. Significance and Use
6.1.7 Fluorocarbon Tubing, 0.6 m long by 3.2 mm o.d. to
5.1 Excessive levels of hydrogen sulfide in the vapor phase
connect components together.
above residual fuel oils in storage tanks may result in health
6.2 Vacuum pump, 3.2 mm o.d. outlet, capable of achieving
hazard, OSHA limits violation, and public complaint. An
a 0.2 kPa vacuum and with a capacity of 100 mL/min.
additional concern is corrosion that can be caused by the
6.3 Headspace Oven, capable of operating at 60 6 0.5°C
presenceofH Sduringrefiningandotherproductionactivities.
with internal dimensions of 30 by 30 by 30 cm. An optional
Control measures to maintain safe levels of H S require a
vent line is recommended in case a vial leaks.
consistent method for the assessment of potentially hazardous
6.4 Analytical Balance, sensitivity of 0.01 mg, maximum
levels of H S in fuel oils. (Warning— H S is a highly toxic
2 2
weight of 250 g.
substance. Extreme care must be used in the sampling and
6.5 Data Handling System, such as electronic integrator or
handling of samples that are suspected of containing high
any computer unit that can work with a chromatographic
levels of H S.)
signal.
5.2 Aconcentrationof0.1µg/g(ppmw)ofH Sintheliquid
6.6 If sulfur specific detectors are used instead of an H S
phaseofaNo.4,5,or6residualfueloilcangenerateanactual
analyzer then a chromatographic system equipped with a
gasconcentrationof10to100µL/L(ppmv)ofH Sinthevapor
suitable column and oven is required to separate H S from
phase; therefore an accurate analytical method is required to
other sulfur compounds (see Test Method D5504).
determine the total H S concentration of these residual fuel
6.7 Hand Crimper, to crimp 20 mm diameter aluminum
oils. This test method was developed so refiners, fuel terminal
seals.
operators, and independent testing laboratory personnel can
analytically measure the amount of H S in residual fuel oils.
7. Reagents and Materials
5.3 Test Method D5705 provides a simple and consistent
7.1 Purity of Reagents—Reagent grade chemicals shall be
field test method for the rapid determination of HSinthe
used in all tests. Unless otherwise indicated, it is intended that
residual fuel oils storage tank vapor phase. However, it does
all reagents conform to the specifications of the Committee on
not necessarily simulate the vapor phase H S concentration of
Analytical Reagents of theAmerican Chemical Society where
a fuel storage tank nor does it provide any indication of the 11
such specifications are available. Other grades may be used,
liquid phase H S concentration. This test method provides a
provided it is first ascertained that the reagent is of sufficiently
quantitative measure of a residual fuel oils liquid phase H S
high purity to permit its use without lessening the accuracy of
concentration. It requires a laboratory and a skilled operator to
the determination.
perform the test but gives a more quantitative indication of
potential H S exposure than Test Method D5705.
The Model 695 may be a suitable apparatus. It is available from HoustonAtlas
NOTE 1—Because of the reactivity, absorptivity, and volatility of H S Company.
Good performance has been obtained with a lead acetate tape detector and a
sulfur chemiluminescence detector.
Reagent Chemicals, American Chemical Society Specifications, American
DeterminationofH SinResidualFuelOilsbyMultipleHeadspaceExtraction: Chemical Society, Washington, DC. For suggestions on the testing of reagents not
A Critical Evaluation of Available Analytical Methods. Silva, B., Carvajal, N., listed by the American Chemical Society, see Analar Standards for Laboratory
Gonzalez, A., Eastern Analytical Symposium, sponsored by American Chemical Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Society and theAmerican Microchemical Society, November 16–20, 1992, Somer- and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
set, N.J. MD.
e1
D 6021 – 96 (2001)
FIG. 1 Schematic of Headspace Analysis System
7.2 Acetic Acid Solution—Add 50 mLof glacial acetic acid 7.10 Side Port Needles,forpressurelock,A-gasseries(with
(CH COOH) to a 1-L volumetric flask and then add Type II reduction union 3.2 mm to 1.6 mm).
distilled water, as specified in Specification D1193, to the 1-L 7.11 Syringe Needles, common dischargeable (dosing
mark to make a 5% acetic acid solution. needle).
7.3 Aluminum Seals, 20 mm diameter to seal septas to
8. Sampling
headspace sample vials.
7.4 Headspace Vials, 30-, 60-, or 120-mLborosilicate glass
8.1 Using a suitable H S inert container of 250 to 500 mL,
vials with 20 mm mouth diameter. collect a representative sample by Practice D4057. Suitable
7.5 Hydrogen Sulfide Gas Calibration Standard , 1, 10, and
containers can be made of borosilicate glass or aluminum. If
100 µL/L H S in helium or nitrogen high pressure cylinders the sample temperature is below 60°C then a high density
(obtain from gas supply company). (Warning— Hydrogen
polyethylene bottle can be used.
sulfide is an extremely toxic gas.) 8.2 Fill the container completely to the top so that there is
7.6 Gases, helium or nitrogen (H S free), chemically pure
no headspace in the container. Cap immediately.
grade or purified, as carrier gas to sweep sample into the (Warning—At no time should the container temperature be
detector.
allowed to exceed the temperature of the sample at the time.)
7.7 Lead Acetate Sensing Paper—Prepare in accordance 8.3 Takethesamplestothelaboratorypreferablywithinone
with Test Method D2420, using appropriate size strips and to four hours, within 24 h maximum. Place the samples in
drying in an H S-free environment. Commercially available refrigerated storage. Store samples until analysis time but not
test paper has been found satisfactory. more than three days.
NOTE 2—Reagents from 7.2 and 7.7 are only needed if using an H S
9. Preparation of Apparatus
lead acetate tape detector.
9.1 Assemble the headspace sampling system as shown in
7.8 Nuts and Ferrules, Polytetrafluoroethylene (PTFE) and
Fig. 1.
stainless steel (3.2 mm).
9.2 Because of the chemical activity and adsorptive proper-
7.9 Septas, 20 mm diameter PTFE silicone/fluorocarbon to
ties of H S, it is highly desirable to connect the components of
seal headspace sample vials.
the test apparatus together using minimum lengths of alumi-
num or fluorocarbon sample lines. (Warning— To preclude
the formation of mercaptide gels and to reduce problems
H S gas calibration standard supplied byAirco has been found to be suitable
associated with corrosion do not use brass or copper flow
(stable concentration over time).
Lead acetate sensing paper is available from Houston Atlas. system parts.)
e1
D 6021 – 96 (2001)
include: heating a solid to generate H S and then using a permeation tube
10. Calibration and Standardization
as discussed in Practice D3609 or using pure H S and a movable piston
10.1 Filling Head Space Vial With Gas Calibration Stan-
as discussed in Test Method D4084.
dard:
10.2 Calibration of Analyzer:
10.1.1 Depending on the expected concentration use, a 1
10.2.1 Place the headspace vial in a 60°C oven for at least
µL/L (#0.1µ g/g) in a 120-mL headspace vial, 10 µL/L (;1
5 min but for no more than 15 min. Install an 0.5-mL sample
µg/g) in a 60-mLheadspace vial, or 100 µL/L(;10 µg/g) in a
loopifusingthe100µL/LH Sstandard,a2.5mLsampleloop
30-mL headspace vial, H S gas standard to calibrate the
ifusingthe10µL/LH Sstandard,anda10-mLsampleloopif
headspace sampling system. 2
using the 1 µL/L H S standard. With Valve 2 in the load
NOTE 3—Partspermillionbyvolumeunits(µL/L),equivalenttomicro
position, see Fig. 1 and Valve 1 closed, evacuate the sample
moles per mole, are used because of the convenience in use of volume
loopbyopeningValve3.Whenavacuumofatleast−70kPag
measurements rather than weight for a gas standard.
is achieved, then close Valve 3.
10.1.2 Insertasilicone/fluorocarbonseptum,withthePTFE
10.2.2 Immediately insert the sampling needle (Fig. 1)
side pointing inwards, into the headspace vial, cover it with an
through the septum of the headspace vial containing the
aluminum seal, and crimp the aluminum seal with the hand
calibration gas mixt
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.