Loading (50 kb)...'
(continued)
1,2,3,6,7,8-HxCDD......................................... ............ ........... 200 4
1,2,3,7,8,9-HxCDD......................................... ............ ........... 200 4
1,2,3,4,7,8-HxCDF......................................... ............ ........... 200 4
1,2,3,6,7,8-HxCDF......................................... ............ ........... 200 4
1,2,3,7,8,9-HxCDF......................................... ............ ........... 200 4
2,3,4,6,7,8-HxCDF......................................... ............ ........... 200 4
1,2,3,4,6,7,8-HpCDD....................................... ............ ........... 200 4
1,2,3,4,6,7,8-HpCDF....................................... ............ ........... 200 4
1,2,3,4,7,8,9-HpCDF....................................... ............ ........... 200 4
OCDD...................................................... ............ ........... 400 8
OCDF...................................................... ............ ........... 400 8
13C12-2,3,7,8-TCDD........................................ 100 2 ........... ............
13C12-2,3,7,8-TCDF........................................ 100 2 ........... ............
13C12-1,2,3,7,8-PeCDD..................................... 100 2 ........... ............
13C12-1,2,3,7,8-PeCDF..................................... 100 2 ........... ............
13C12-2,3,4,7,8-PeCDF..................................... 100 2 ........... ............
13C12-1,2,3,4,7,8-HxCDD................................... 100 2 ........... ............
13C12-1,2,3,6,7,8-HxCDD................................... 100 2 ........... ............
13C12-1,2,3,4,7,8-HxCDF................................... 100 2 ........... ............
13C12-1,2,3,6,7,8-HxCDF................................... 100 2 ........... ............
13C12-1,2,3,7,8,9-HxCDF................................... 100 2 ........... ............
13C12-2,3,4,6,7,8-HxCDF................................... 100 2 ........... ............
13C12-1,2,3,4,6,7,8-HpCDD................................. 100 2 ........... ............
13C12-1,2,3,4,6,7,8-HpCDF................................. 100 2 ........... ............
13C12-1,2,3,4,7,8,9-HpCDF................................. 100 2 ........... ............
13C12-OCDD................................................ 200 4 ........... ............
Cleanup Standard \5\
37Cl4-2,3,7,8-TCDD.................................... 0.8 ........... ........... ............
Internal Standards \6\
13C12-1,2,3,4-TCDD.................................... 200 ........... ........... ............
13C12-1,2,3,7,8,9-HxCDD............................... 200 ........... ........... ............
----------------------------------------------------------------------------------------------------------------
\1\ Section 7.10_prepared in nonane and diluted to prepare spiking solution.
\2\ Section 7.10.3_prepared in acetone from stock solution daily.
\3\ Section 7.9_prepared in nonane and diluted to prepare spiking solution.
\4\ Section 7.14_prepared in acetone from stock solution daily.
\5\ Section 7.11_prepared in nonane and added to extract prior to cleanup.
\6\ Section 7.12_prepared in nonane and added to the concentrated extract immediately prior to injection into
the GC (Section 14.2).
Table 4_Concentration of CDDS/CDFS in Calibration and Calibration Verification Solutions \1\ (Section 15.3)
----------------------------------------------------------------------------------------------------------------
CDD/CDF CS2 (ng/mL) CS3 (ng/mL) CS4 (ng/mL) CS5 (ng/mL)
----------------------------------------------------------------------------------------------------------------
2,3,7,8-TCDD.................................. 0.5 2 10 40 200
2,3,7,8-TCDF.................................. 0.5 2 10 40 200
1,2,3,7,8-PeCDD............................... 2.5 10 50 200 1000
1,2,3,7,8-PeCDF............................... 2.5 10 50 200 1000
2,3,4,7,8-PeCDF............................... 2.5 10 50 200 1000
1,2,3,4,7,8-HxCDD............................. 2.5 10 50 200 1000
1,2,3,6,7,8-HxCDD............................. 2.5 10 50 200 1000
1,2,3,7,8,9-HxCDD............................. 2.5 10 50 200 1000
1,2,3,4,7,8-HxCDF............................. 2.5 10 50 200 1000
1,2,3,6,7,8-HxCDF............................. 2.5 10 50 200 1000
1,2,3,7,8,9-HxCDF............................. 2.5 10 50 200 1000
2,3,4,6,7,8-HxCDF............................. 2.5 10 50 200 1000
1,2,3,4,6,7,8-HpCDD........................... 2.5 10 50 200 1000
1,2,3,4,6,7,8-HpCDF........................... 2.5 10 50 200 1000
1,2,3,4,7,8,9-HpCDF........................... 2.5 10 50 200 1000
OCDD.......................................... 5.0 20 100 400 2000
OCDF.......................................... 5.0 20 100 400 2000
13 C12-2,3,7,8-TCDD........................... 100 100 100 100 100
13 C12-2,3,7,8-TCDF........................... 100 100 100 100 100
13 C12-1,2,3,7,8-PeCDD........................ 100 100 100 100 100
13 C12-PeCDF.................................. 100 100 100 100 100
13 C12-2,3,4,7,8-PeCDF........................ 100 100 100 100 100
13 C12-1,2,3,4,7,8-HxCDD...................... 100 100 100 100 100
13 C12-1,2,3,6,7,8-HxCDD...................... 100 100 100 100 100
13 C12-1,2,3,4,7,8-HxCDF...................... 100 100 100 100 100
13 C12-1,2,3,6,7,8-HxCDF...................... 100 100 100 100 100
13 C12-1,2,3,7,8,9-HxCDF...................... 100 100 100 100 100
13 C12-1,2,3,4,6,7,8-HpCDD.................... 100 100 100 100 100
13 C12-1,2,3,4,6,7,8-HpCDF.................... 100 100 100 100 100
13 C12-1,2,3,4,7,8,9-Hp CDF................... 100 100 100 100 100
13 C12-OCDD................................... 200 200 200 200 200
Cleanup Standard:
37 C14-2,3,7,8-TCDD....................... 0.5 2 10 40 200
Internal Standards:
13 C12-1,2,3,4-TCDD........................... 100 100 100 100 100
13 C12-1,2,3,7,8,9-HxCDD...................... 100 100 100 100 100
----------------------------------------------------------------------------------------------------------------
Table 5_GC Retention Time Window Defining Solution and Isomer Specificity Test Standard (Section 7.15)
----------------------------------------------------------------------------------------------------------------
DB-5 column GC retention-time window defining solution
-----------------------------------------------------------------------------------------------------------------
CDD/CDF First eluted Last eluted
----------------------------------------------------------------------------------------------------------------
TCDF................................. 1,3,6,8-.................................. 1,2,8,9-
TCDD................................. 1,3,6,8-.................................. 1,2,8,9-
PeCDF................................ 1,3,4,6,8-................................ 1,2,3,8,9-
PeCDD................................ 1,2,4,7,9-................................ 1,2,3,8,9-
HxCDF................................ 1,2,3,4,6,8-.............................. 1,2,3,4,8,9-
HxCDD................................ 1,2,4,6,7,9-.............................. 1,2,3,4,6,7-
HpCDF................................ 1,2,3,4,6,7,8-............................ 1,2,3,4,7,8,9-
HpCDD................................ 1,2,3,4,6,7,9-............................ 1,2,3,4,6,7,8-
----------------------------------------------------------------------------------------------------------------
DB-5 Column TCDD Specificity Test Standard
1,2,3,7=1,2,3,8-TCDD
2,3,7,8-TCDD
1,2,3,9-TCDD
DB-225 Column TCDF Isomer Specificity Test Standard
2,3,4,7-TCDF
2,3,7,8-TCDF
1,2,3,9-TCDF
Table 6_Acceptance Criteria for Performance Tests When All CDDS/CDFS Are Tested \1\
----------------------------------------------------------------------------------------------------------------
IPR 2,3
CDD/CDF Test conc. ---------------------------- OPR (ng/mL) VER (ng/mL)
(ng/mL) s (ng/mL) X (ng/mL)
----------------------------------------------------------------------------------------------------------------
2,3,7,8-TCDD............................... 10 2.8 8.3-12.9 6.7-15.8 7.8-12.9
2,3,7,8-TCDF............................... 10 2.0 8.7-13.7 7.5-15.8 8.4-12.0
1,2,3,7,8-PeCDD............................ 50 7.5 38-66 35-71 39-65
1,2,3,7,8-PeCDF............................ 50 7.5 43-62 40-67 41-60
2,3,4,7,8-PeCDF............................ 50 8.6 36-75 34-80 41-61
1,2,3,4,7,8-HxCDD.......................... 50 9.4 39-76 35-82 39-64
1,2,3,6,7,8-HxCDD.......................... 50 7.7 42-62 38-67 39-64
1,2,3,7,8,9-HxCDD.......................... 50 11.1 37-71 32-81 41-61
1,2,3,4,7,8-HxCDF.......................... 50 8.7 41-59 36-67 45-56
1,2,3,6,7,8-HxCDF.......................... 50 6.7 46-60 42-65 44-57
1,2,3,7,8,9-HxCDF.......................... 50 6.4 42-61 39-65 45-56
2,3,4,6,7,8-HxCDF.......................... 50 7.4 37-74 35-78 44-57
1,2,3,4,6,7,8-HpCDD........................ 50 7.7 38-65 35-70 43-58
1,2,3,4,6,7,8-HpCDF........................ 50 6.3 45-56 41-61 45-55
1,2,3,4,7,8,9-HpCDF........................ 50 8.1 43-63 39-69 43-58
OCDD....................................... 100 19 89-127 78-144 79-126
OCDF....................................... 100 27 74-146 63-170 63-159
13C12-2,3,7,8-TCDD......................... 100 37 28-134 20-175 82-121
13C12-2,3,7,8-TCDF......................... 100 35 31-113 22-152 71-140
13C12-1,2,3,7,8-PeCDD...................... 100 39 27-184 21-227 62-160
13C12-1,2,3,7,8-PeCDF...................... 100 34 27-156 21-192 76-130
13C12-2,3,4,7,8-PeCDF...................... 100 38 16-279 13-328 77-130
13C12-1,2,3,4,7,8-HxCDD.................... 100 41 29-147 21-193 85-117
13C12-1,2,3,6,7,8-HxCDD.................... 100 38 34-122 25-163 85-118
13C12-1,2,3,4,7,8-HxCDF.................... 100 43 27-152 19-202 76-131
13C12-1,2,3,6,7,8-HxCDF.................... 100 35 30-122 21-159 70-143
13C12-1,2,3,7,8,9-HxCDF.................... 100 40 24-157 17-205 74-135
13C12-2,3,4,6,7,8,-HxCDF................... 100 37 29-136 22-176 73-137
13C12-1,2,3,4,6,7,8-HpCDD.................. 100 35 34-129 26-166 72-138
13C12-1,2,3,4,6,7,8-HpCDF.................. 100 41 32-110 21-158 78-129
13C12-1,2,3,4,7,8,9-HpCDF.................. 100 40 28-141 20-186 77-129
13C12-OCDD................................. 200 95 41-276 26-397 96-415
37Cl4-2,3,7,8-TCDD......................... 10 3.6 3.9-15.4 3.1-19.1 7.9-12.7
----------------------------------------------------------------------------------------------------------------
\1\ All specifications are given as concentration in the final extract, assuming a 20 µL volume.
\2\ s = standard deviation of the concentration.
\3\ X = average concentration.
Table 6a_Acceptance Criteria for Performance Tests When Only Tetra Compounds are Tested 1
----------------------------------------------------------------------------------------------------------------
IPR 2,3
CDD/CDF Test Conc. --------------------------- OPR (ng/mL) VER (ng/mL)
(ng/mL) s (ng/mL) X (ng/mL)
----------------------------------------------------------------------------------------------------------------
2,3,7,8-TCDD................................ 10 2.7 8.7-12.4 7.314.6 8.2-12.3
2,3,7,8-TCDF................................ 10 2.0 9.1-13.1 8.0-14.7 8.6-11.6
13C12-2,3,7,8-TCDD.......................... 100 35 32-115 25-141 85-117
13C12-2,3,7,8-TCDF.......................... 100 34 35-99 26-126 76-131
37Cl4-2,3,7,8-TCDD.......................... 10 3.4 4.5-13.4 3.7-15.8 8.3-12.1
----------------------------------------------------------------------------------------------------------------
1 All specifications are given as concentration in the final extract, assuming a 20 µL volume.
2 s = standard deviation of the concentration.
3 X = average concentration.
Table 7_Labeled Compounds Recovery in Samples When all CDDS/CDFS are
Tested
------------------------------------------------------------------------
Labeled compound recovery
Compound Test conc. --------------------------
(ng/mL) (ng/mL) 1 (%)
------------------------------------------------------------------------
13C12-2,3,7,8-TCDD.............. 100 25-164 25-164
13C12-2,3,7,8-TCDF.............. 100 24-169 24-169
13C12-1,2,3,7,8-PeCDD........... 100 25-181 25-181
13C12-1,2,3,7,8-PeCDF........... 100 24-185 24-185
13C12-2,3,4,7,8-PeCDF........... 100 21-178 21-178
13C12-1,2,3,4,7,8-HxCDD......... 100 32-141 32-141
13C12-1,2,3,6,7,8-HxCDD......... 100 28-130 28-130
13C12-1,2,3,4,7,8-HxCDF......... 100 26-152 26-152
13C12-1,2,3,6,7,8-HxCDF......... 100 26-123 26-123
13C12-1,2,3,7,8,9-HxCDF......... 100 29-147 29-147
13C12-2,3,4,6,7,8-HxCDF......... 100 28-136 28-136
13C12-1,2,3,4,6,7,8-HpCDD....... 100 23-140 23-140
13C12-1,2,3,4,6,7,8-HpCDF....... 100 28-143 28-143
13C12-1,2,3,4,7,8,9-HpCDF....... 100 26-138 26-138
13C12-OCDD...................... 200 34-313 17-157
37Cl4-2,3,7,8-TCDD.............. 10 3.5-19.7 35-197
------------------------------------------------------------------------
1 Specification given as concentration in the final extract, assuming a
20-µL volume.
Table 7a_Labeled Compound Recovery in Samples When Only Tetra Compounds
are Tested
------------------------------------------------------------------------
Labeled compound recovery
Compound Test conc. --------------------------
(ng/mL) (ng/mL) \1\ (%)
------------------------------------------------------------------------
13C12-2,3,7,8-TCDD.............. 100 31-137 31-137
13C12-2,3,7,8-TCDF.............. 100 29-140 29-140
37Cl4-2,3,7,8-TCDD.............. 10 4.2-16.4 42-164
------------------------------------------------------------------------
\1\ Specification given as concentration in the final extract, assuming
a 20 µL volume.
Table 8_Descriptors, Exact M/Z's, M/Z Types, and Elemental Compositions of the CDDs and CDFs
----------------------------------------------------------------------------------------------------------------
Exact M/Z
Descriptor \1\ M/Z type Elemental composition Substance \2\
----------------------------------------------------------------------------------------------------------------
1........................ 292.9825 Lock C7F11.................... PFK
303.9016 M C12H435Cl4O.............. TCDF
305.8987 M=2 C12H435Cl337ClO.......... TCDF
315.9419 M 13C12H435Cl4O............ TCDF \3\
317.9389 M=2 13C12H435Cl337ClO........ TCDF \3\
319.8965 M C12H435Cl4O2............. TCDD
321.8936 M=2 C12H435Cl337ClO2......... TCDD
327.8847 M C12H437Cl4O2............. TCDD \4\
330.9792 QC C7F13.................... PFK
331.9368 M 13C12H435Cl4O2........... TCDD \3\
333.9339 M=2 13C12H435Cl337ClO2....... TCDD \3\
375.8364 M=2 C12H435Cl537ClO.......... HxCDPE
2........................ 339.8597 M=2 C12H335Cl437ClO.......... PeCDF
341.8567 M=4 C12H335Cl337Cl2O......... PeCDF
351.9000 M=2 13C12H335Cl437ClO........ PeCDF
353.8970 M=4 13C12H335Cl337Cl2O....... PeCDF \3\
354.9792 Lock C9F13.................... PFK
355.8546 M=2 C12H335Cl437ClO2......... PeCDD
357.8516 M=4 C12H335Cl337Cl2O2........ PeCDD
367.8949 M=2 13C12H335Cl437ClO2....... PeCDD \3\
369.8919 M=4 13C12H335Cl337Cl2O2...... PeCDD \3\
409.7974 M=2 C12H335Cl637ClO.......... HpCDPE
3........................ 373.8208 M=2 C12H235Cl537ClO.......... HxCDF
375.8178 M=4 C12H235Cl437Cl2O......... HxCDF
383.8639 M 13C12H235Cl6O............ HxCDF \3\
385.8610 M=2 13C12H235Cl537ClO........ HxCDF \3\
389.8157 M=2 C12H235Cl537ClO2......... HxCDD
391.8127 M=4 C12H235Cl437Cl2O2........ HxCDD
392.9760 Lock C9F15.................... PFK
401.8559 M=2 13C12H235Cl537ClO2....... HxCDD \3\
403.8529 M=4 13C12H235Cl437Cl2O2...... HxCDD \3\
430.9729 QC C9F17.................... PFK
445.7555 M=4 C12H235Cl637Cl2O......... OCDPE
4........................ 407.7818 M=2 C12H35Cl637ClO........... HpCDF
409.7789 M=4 C12H35Cl537Cl2O.......... HpCDF
417.8253 M 13C12H35Cl7O............. HpCDF \3\
419.8220 M=2 13C12H35Cl637ClO......... HpCDF \3\
423.7766 M=2 C12H35Cl637ClO2.......... HpCDD
425.7737 M=4 C12H35Cl537Cl2O2......... HpCDD
430.9729 Lock C9F17.................... PFK
435.8169 M=2 13C12H35Cl637ClO2........ HpCDD \3\
437.8140 M=4 13C12H35Cl537Cl2O2....... HpCDD \3\
479.7165 M=4 C12H35Cl737Cl2O.......... NCDPE
5........................ 441.7428 M=2 C1235Cl737ClO............ OCDF
442.9728 Lock C10F17................... PFK
443.7399 M=4 C1235Cl637Cl2O........... OCDF
457.7377 M=2 C1235Cl737ClO2........... OCDD
459.7348 M=4 C1235Cl637Cl2O2.......... OCDD
469.7779 M=2 13C1235Cl737ClO2......... OCDD \3\
471.7750 M=4 13C1235Cl637Cl2O2........ OCDD \3\
513.6775 M=4 C1235Cl837Cl2O........... DCDPE
----------------------------------------------------------------------------------------------------------------
\1\ Nuclidic masses used:
H = 1.007825.
O = 15.994915.
C = 12.00000.
35Cl = 34.968853.
13C = 13.003355.
37Cl = 36.965903.
F = 18.9984.
\2\ TCDD = Tetrachlorodibenzo-p-dioxin.
PeCDD = Pentachlorodibenzo-p-dioxin.
HxCDD = Hexachlorodibenzo-p-dioxin.
HpCDD = Heptachlorodibenzo-p-dioxin.
OCDD = Octachlorodibenzo-p-dioxin.
HxCDPE = Hexachlorodiphenyl ether.
OCDPE = Octachlorodiphenyl ether.
DCDPE = Decachlorodiphenyl ether.
TCDF = Tetrachlorodibenzofuran.
PeCDF = Pentachlorodibenzofuran.
HxCDF = Hexachlorodibenzofuran.
HpCDF = Heptachlorodibenzofuran.
OCDF = Octachlorodibenzofuran.
HpCDPE = Heptachlorodiphenyl ether.
NCDPE = Nonachlorodiphenyl ether.
PFK = Perfluorokerosene.
\3\ Labeled compound.
\4\ There is only one m/z for 37Cl4-2,3,7,8,-TCDD (cleanup standard).
Table 9_Theoretical Ion Abundance Ratios and QC Limits
----------------------------------------------------------------------------------------------------------------
QC limit \1\
Number of chlorine atoms M/Z's forming ratio Theoretical -------------------------
ratio Lower Upper
----------------------------------------------------------------------------------------------------------------
4 \2\................................... M/(M=2)........................ 0.77 0.65 0.89
5....................................... (M=2)/(M=4).................... 1.55 1.32 1.78
6....................................... (M=2)/(M=4).................... 1.24 1.05 1.43
6 \3\................................... M/(M=2)........................ 0.51 0.43 0.59
7....................................... (M=2)/(M=4).................... 1.05 0.88 1.20
7 \4\................................... M/(M=2)........................ 0.44 0.37 0.51
8....................................... (M=2)/(M=4).................... 0.89 0.76 1.02
----------------------------------------------------------------------------------------------------------------
\1\ QC limits represent ±15% windows around the theoretical ion abundance ratios.
\2\ Does not apply to 37Cl4-2,3,7,8-TCDD (cleanup standard).
\3\ Used for 13C12-HxCDF only.
\4\ Used for 13C12-HpCDF only.
Table 10_Suggested Sample Quantities To Be Extracted for Various Matrices \1\
----------------------------------------------------------------------------------------------------------------
Quantity
Sample Matrix \2\ Example Percent solids Phase extracted
----------------------------------------------------------------------------------------------------------------
Single-phase:
Aqueous...................... Drinking water...... <1 (\3\)............... 1000 mL.
Groundwater
Treated wastewater
Solid........................ Dry soil............ >20 Solid............... 10 g.
Compost
Ash
Organic...................... Waste solvent....... <1 Organic............. 10 g.
Waste oil
Organic polymer
Tissue....................... Fish................ .............. Organic............. 10 g.
Human adipose
Multi-phase:
Liquid/Solid:
Aqueous/Solid............ Wet soil............ 1-30 Solid............... 10 g.
Untreated effluent..
Digested municipal
sludge.
Filter cake.........
Paper pulp..........
Organic/solid............ Industrial sludge... 1-100 Both................ 10 g.
Oily waste
Liquid/Liquid:
Aqueous/organic.......... In-process effluent. <1 Organic............. 10 g.
Untreated effluent
Drum waste
Aqueous/organic/solid.... Untreated effluent.. >1 Organic and solid... 10 g.
Drum waste
----------------------------------------------------------------------------------------------------------------
\1\ The quantity of sample to be extracted is adjusted to provide 10 g of solids (dry weight). One liter of
aqueous samples containing 1% solids will contain 10 g of solids. For aqueous samples containing greater than
1% solids, a lesser volume is used so that 10 g of solids (dry weight) will be extracted.
\2\ The sample matrix may be amorphous for some samples. In general, when the CDDs/CDFs are in contact with a
multiphase system in which one of the phases is water, they will be preferentially dispersed in or adsorbed on
the alternate phase because of their low solubility in water.
\3\ Aqueous samples are filtered after spiking with the labeled compounds. The filtrate and the materials
trapped on the filter are extracted separately, and the extracts are combined for cleanup and analysis.
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24.0 Glossary of Definitions and Purposes
These definitions and purposes are specific to this method but have been conformed to common usage as much as possible.
24.1 Units of weight and Measure and Their Abbreviations.
24.1.1 Symbols:
°C—degrees Celsius
µL—microliter
µm—micrometer
<—less than
>—greater than
%—percent
24.1.2 Alphabetical abbreviations:
amp—ampere
cm—centimeter
g—gram
h—hour
D—inside diameter
in.—inch
L—liter
M—Molecular ion
m—meter
mg—milligram
min—minute
mL—milliliter
mm—millimeter
m/z—mass-to-charge ratio
N—normal; gram molecular weight of solute divided by hydrogen equivalent of solute, per liter of solution
OD—outside diameter
pg—picogram
ppb—part-per-billion
ppm—part-per-million
ppq—part-per-quadrillion
ppt—part-per-trillion
psig—pounds-per-square inch gauge
v/v—volume per unit volume
w/v—weight per unit volume
24.2 Definitions and Acronyms (in Alphabetical Order).
Analyte—A CDD or CDF tested for by this method. The analytes are listed in Table 1.
Calibration Standard (CAL)—A solution prepared from a secondary standard and/or stock solutions and used to calibrate the response of the instrument with respect to analyte concentration.
Calibration Verification Standard (VER)—The mid-point calibration standard (CS3) that is used in to verify calibration. See Table 4.
CDD—Chlorinated Dibenzo-p-ioxin—The isomers and congeners of tetra-through octa-chlorodibenzo-p-dioxin.
CDF—Chlorinated Dibenzofuran—The isomers and congeners of tetra-through octa-chlorodibenzofuran.
CS1, CS2, CS3, CS4, CS5—See Calibration standards and Table 4.
Field Blank—An aliquot of reagent water or other reference matrix that is placed in a sample container in the laboratory or the field, and treated as a sample in all respects, including exposure to sampling site conditions, storage, preservation, and all analytical procedures. The purpose of the field blank is to determine if the field or sample transporting procedures and environments have contaminated the sample.
GC—Gas chromatograph or gas chromatography.
GPC—Gel permeation chromatograph or gel permeation chromatography.
HPLC—High performance liquid chromatograph or high performance liquid chromatography.
HRGC—High resolution GC.
HRMS—High resolution MS.
IPR—Initial precision and recovery; four aliquots of the diluted PAR standard analyzed to establish the ability to generate acceptable precision and accuracy. An IPR is performed prior to the first time this method is used and any time the method or instrumentation is modified.
K-D—Kuderna-Danish concentrator; a device used to concentrate the analytes in a solvent.
Laboratory Blank—See method blank.
Laboratory Control sample (LCS)—See ongoing precision and recovery standard (OPR).
Laboratory Reagent Blank—See method blank.
May—This action, activity, or procedural step is neither required nor prohibited.
May Not—This action, activity, or procedural step is prohibited.
Method Blank—An aliquot of reagent water that is treated exactly as a sample including exposure to all glassware, equipment, solvents, reagents, internal standards, and surrogates that are used with samples. The method blank is used to determine if analytes or interferences are present in the laboratory environment, the reagents, or the apparatus.
Minimum Level (ML)—The level at which the entire analytical system must give a recognizable signal and acceptable calibration point for the analyte. It is equivalent to the concentration of the lowest calibration standard, assuming that all method-specified sample weights, volumes, and cleanup procedures have been employed.
MS—Mass spectrometer or mass spectrometry.
Must—This action, activity, or procedural step is required.
OPR—Ongoing precision and recovery standard (OPR); a laboratory blank spiked with known quantities of analytes. The OPR is analyzed exactly like a sample. Its purpose is to assure that the results produced by the laboratory remain within the limits specified in this method for precision and recovery.
PAR—Precision and recovery standard; secondary standard that is diluted and spiked to form the IPR and OPR.
PFK—Perfluorokerosene; the mixture of compounds used to calibrate the exact m/z scale in the HRMS.
Preparation Blank—See method blank.
Primary Dilution Standard—A solution containing the specified analytes that is purchased or prepared from stock solutions and diluted as needed to prepare calibration solutions and other solutions.
Quality Control Check Sample (QCS)—A sample containing all or a subset of the analytes at known concentrations. The QCS is obtained from a source external to the laboratory or is prepared from a source of standards different from the source of calibration standards. It is used to check laboratory performance with test materials prepared external to the normal preparation process.
Reagent Water—Water demonstrated to be free from the analytes of interest and potentially interfering substances at the method detection limit for the analyte.
Relative Standard Deviation (RSD)—The standard deviation times 100 divided by the mean. Also termed “coefficient of variation.”
RF—Response factor. See Section 10.6.1.
RR—Relative response. See Section 10.5.2.
RSD—See relative standard deviation.
SDS—Soxhlet/Dean-Stark extractor; an extraction device applied to the extraction of solid and semi-solid materials (Reference 7).
Should—This action, activity, or procedural step is suggested but not required.
SICP—Selected ion current profile; the line described by the signal at an exact m/z.
SPE—Solid-phase extraction; an extraction technique in which an analyte is extracted from an aqueous sample by passage over or through a material capable of reversibly adsorbing the analyte. Also termed liquid-solid extraction.
Stock Solution—A solution containing an analyte that is prepared using a reference material traceable to EPA, the National Institute of Science and Technology (NIST), or a source that will attest to the purity and authenticity of the reference material.
TCDD—Tetrachlorodibenzo-p-dioxin.
TCDF—Tetrachlorodibenzofuran.
VER—See calibration verification standard.
Method 1624 Revision B—Volatile Organic Compounds by Isotope Dilution GC/MS
1. Scope and Application
1.1 This method is designed to determine the volatile toxic organic pollutants associated with the 1976 Consent Decree and additional compounds amenable to purge and trap gas chromatography-mass spectrometry (GC/MS).
1.2 The chemical compounds listed in table 1 may be determined in municipal and industrial discharges by this method. The methmd is designed to meet the survey requirements of Effluent Guidelines Division (EGD) and the National Pollutants Discharge Elimination System (NPDES) under 40 CFR 136.1 and 136.5. Any modifications of this method, beyond those expressly permitted, shall be considered as major modifications subject to application and approval of alternate test procedures under 40 CFR 136.4 and 136.5.
1.3 The detection limit of this method is usually dependent on the level of interferences rather than instrumental limitations. The limits in table 2 represent the minimum quantity that can be detected with no interferences present.
1.4 The GC/MS portions of this method are for use only by analysts experienced with GC/MS or under the close supervision of such qualified persons. Laboratories unfamiliar with the analyses of environmental samples by GC/MS should run the performance tests in reference 1 before beginning.
2. Summary of Method
2.1 Stable isotopically labeled analogs of the compounds of interest are added to a 5 mL water sample. The sample is purged at 20–25 °C with an inert gas in a specially designed chamber. The volatile organic compounds are transferred from the aqueous phase into the gaseous phase where they are passed into a sorbent column and trapped. After purging is completed, the trap is backflushed and heated rapidly to desorb the compounds into a gas chromatograph (GC). The compounds are separated by the GC and detected by a mass spectrometer (MS) (references 2 and 3). The labeled compounds serve to correct the variability of the analytical technique.
2.2 Identification of a compound (qualitative analysis) is performed by comparing the GC retention time and the background corrected characteristic spectral masses with those of authentic standards.
2.3 Quantitative analysis is performed by GC/MS using extracted ion current profile (EICP) areas. Isotope dilution is used when labeled compounds are available; otherwise, an internal standard method is used.
2.4 Quality is assured through reproducible calibration and testing of the purge and trap and GC/MS systems.
3. Contamination and Interferences
3.1 Impurities in the purge gas, organic compounds out-gassing from the plumbing upstream of the trap, and solvent vapors in the laboratory account for the majority of contamination problems. The analytical system is demonstrated to be free from interferences under conditions of the analysis by analyzing blanks initially and with each sample lot (samples analyzed on the same 8 hr shift), as described in Section 8.5.
3.2 Samples can be contaminated by diffusion of volatile organic compounds (particularly methylene chloride) through the bottle seal during shipment and storage. A field blank prepared from reagent water and carried through the sampling and handling protocol serves as a check on such contamination.
3.3 Contamination by carry-over can occur when high level and low level samples are analyzed sequentially. To reduce carry-over, the purging device and sample syringe are rinsed between samples with reagent water. When an unusually concentrated sample is encountered, it is followed by analysis of a reagent water blank to check for carry-over. For samples containing large amounts of water soluble materials, suspended solids, high boiling compounds, or high levels or purgeable compounds, the purge device is washed with soap solution, rinsed with tap and distilled water, and dried in an oven at 100–125 °C. The trap and other parts of the system are also subject to contamination; therefore, frequent bakeout and purging of the entire system may be required.
3.4 Interferences resulting from samples will vary considerably from source to source, depending on the diversity of the industrial complex or municipality being sampled.
4. Safety
4.1 The toxicity or carcinogenicity of each compound or reagent used in this method has not been precisely determined; however, each chemical compound should be treated as a potential health hazard. Exposure to these compounds should be reduced to the lowest possible level. The laboratory is responsible for maintaining a current awareness file of OSHA regulations regarding the safe handling of the chemicals specified in this method. A reference file of data handling sheets should also be made available to all personnel involved in these analyses. Additional information on laboratory safety can be found in references 4–6.
4.2 The following compounds covered by this method have been tentatively classified as known or suspected human or mammalian carcinogens: benzene, carbon tetrachloride, chloroform, and vinyl chloride. Primary standards of these toxic compounds should be prepared in a hood, and a NIOSH/MESA approved toxic gas respirator should be worn when high concentrations are handled.
5. Apparatus and Materials
5.1 Sample bottles for discrete sampling.
5.1.1 Bottle—25 to 40 mL with screw cap (Pierce 13075, or equivalent). Detergent wash, rinse with tap and distilled water, and dry at >105 °C for one hr minimum before use.
5.1.2 Septum—Teflon-faced silicone (Pierce 12722, or equivalent), cleaned as above and baked at 100–200 °C, for one hour minimum.
5.2 Purge and trap device—consists of purging device, trap, and desorber. Complete devices are commercially available.
5.2.1 Purging device—designed to accept 5 mL samples with water column at least 3 cm deep. The volume of the gaseous head space between the water and trap shall be less than 15 mL. The purge gas shall be introduced less than 5 mm from the base of the water column and shall pass through the water as bubbles with a diameter less than 3 mm. The purging device shown in Figure 1 meets these criteria.
5.2.2 Trap—25 to 30 cm × 2.5 mm i.d. minimum, containing the following:
5.2.2.1 Methyl silicone packing—one ±0.2 cm, 3 percent OV–1 on 60/80 mesh Chromosorb W, or equivalent.
5.2.2.2 Porous polymer—15 ±1.0 cm, Tenax GC (2,6-diphenylene oxide polymer), 60/80 mesh, chromatographic grade, or equivalent.
5.2.2.3 Silica gel—8 ±1.0 cm, Davison Chemical, 35/60 mesh, grade 15, or equivalent. The trap shown in Figure 2 meets these specifications.
5.2.3 Desorber—shall heat the trap to 175 ±5 °C in 45 seconds or less. The polymer section of the trap shall not exceed 180 °C, and the remaining sections shall not exceed 220 °C. The desorber shown in Figure 2 meets these specifications.
5.2.4 The purge and trap device may be a separate unit or coupled to a GC as shown in Figures 3 and 4.
5.3 Gas chromatograph—shall be linearly temperature programmable with initial and final holds, shall contain a glass jet separator as the MS interface, and shall produce results which meet the calibration (Section 7), quality assurance (Section 8), and performance tests (Section 11) of this method.
5.3.1 Column—2.8 ±0.4 m × 2 ±0.5 mm i. d. glass, packekd with one percent SP–1000 on Carbopak B, 60/80 mesh, or equivalent.
5.4 Mass spectrometer—70 eV electron impact ionization; shall repetitively scan from 20 to 250 amu every 2–3 seconds, and produce a unit resolution (valleys between m/z 174–176 less than 10 percent of the height of the m/z 175 peak), background corrected mass spectrum from 50 ng 4-bromo-fluorobenzene (BFB) injected into the GC. The BFB spectrum shall meet the mass-intensity criteria in Table 3. All portions of the GC column, transfer lines, and separator which connect the GC column to the ion source shall remain at or above the column temperature during analysis to preclude condensation of less volatile compounds.
5.5 Data system—shall collect and record MS data, store mass intensity data in spectral libraries, process GC/MS data and generate reports, and shall calculate and record response factors.
5.5.1 Data acquisition—mass spectra shall be collected continuously throughout the analysis and stored on a mass storage device.
5.5.2 Mass spectral libraries—user created libraries containing mass spectra obtained from analysis of authentic standards shall be employed to reverse search GC/MS runs for the compounds of interest (Section 7.2).
5.5.3 Data processing—the data system shall be used to search, locate, identify, and quantify the compounds of interest in each GC/MS analysis. Software routines shall be employed to compute retention times and EICP areas. Displays of spectra, mass chromatograms, and library comparisons are required to verify results.
5.5.4 Response factors and multipoint calibrations—the data system shall be used to record and maintain lists of response factors (response ratios for isotope dilution) and generate multi-point calibration curves (Section 7). Computations of relative standard deviation (coefficient of variation) are useful for testing calibration linearity. Statistics on initial and on-going performance shall be maintained (Sections 8 and 11).
5.6 Syringes—5 mL glass hypodermic, with Luer-lok tips.
5.7 Micro syringes—10, 25, and 100 uL.
5.8 Syringe valves—2-way, with Luer ends (Telfon or Kel-F).
5.9 Syringe—5 mL, gas-tight, with shut-off valve.
5.10 Bottles—15 mL., screw-cap with Telfon liner.
5.11 Balance—analytical, capable of weighing 0.1 mg.
6. Reagents and Standards
6.1 Reagent water—water in which the compounds of interest and interfering compounds are not detected by this method (Section 11.7). It may be generated by any of the following methods:
6.1.1 Activated carbon—pass tap water through a carbon bed (Calgon Filtrasorb-300, or equivalent).
6.1.2 Water purifier—pass tap water through a purifier (Millipore Super Q, or equivalent).
6.1.3 Boil and purge—heat tap water to 90–100 °C and bubble contaminant free inert gas through it for approx one hour. While still hot, transfer the water to screw-cap bottles and seal with a Teflon-lined cap.
6.2 Sodium thiosulfate—ACS granular.
6.3 Methanol—pesticide quality or equivalent.
6.4 Standard solutions—purchased as solution or mixtures with certification to their purity, concentration, and authenticity, or prepared from materials of known purity and composition. If compound purity is 96 percent or greater, the weight may be used without correction to calculate the concentration of the standard.
6.5 Preparation of stock solutions—prepare in methanol using liquid or gaseous standards per the steps below. Observe the safety precautions given in Section 4.
6.5.1 Place approx 9.8 mL of methanol in a 10 mL ground glass stoppered volumetric flask. Allow the flask to stand unstoppered for approximately 10 minutes or until all methanol wetted surfaces have dried. In each case, weigh the flask, immediately add the compound, then immediately reweigh to prevent evaporation losses from affecting the measurement.
6.5.1.1 Liquids—using a 100 µL syringe, permit 2 drops of liquid to fall into the methanol without contacting the leck of the flask. Alternatively, inject a known volume of the compound into the methanol in the flask using a micro-syringe.
6.5.1.2 Gases (chloromethane, bromomethane, chloroethane, vinyl chloride)—fill a valved 5 mL gas-tight syringe with the compound. Lower the needle to approximately 5 mm above the methanol meniscus. Slowly introduce the compound above the surface of the meniscus. The gas will dissolve rapidly in the methanol.
6.5.2 Fill the flask to volume, stopper, then mix by inverting several times. Calculate the concentration in mg/mL (µg/µL ) from the weight gain (or density if a known volume was injected).
6.5.3 Transfer the stock solution to a Teflon sealed screw-cap-bottle. Store, with minimal headspace, in the dark at -10 to -20 °C.
6.5.4 Prepare fresh standards weekly for the gases and 2-chloroethylvinyl ether. All other standards are replaced after one month, or sooner if comparison with check standards indicate a change in concentration. Quality control check standards that can be used to determine the accuracy of calibration standards are available from the US Environmental Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, Ohio.
6.6 Labeled compound spiking solution—from stock standard solutions prepared as above, or from mixtures, prepare the spiking solution to contain a concentration such that a 5–10 µL spike into each 5 mL sample, blank, or aqueous standard analyzed will result in a concentration of 20 µg/L of each labeled compound. For the gases and for the water soluble compounds (acrolein, acrylonitrile, acetone, diethyl ether, and MEK), a concentration of 100 µg/L may be used. Include the internal standards (Section 7.5) in this solution so that a concentration of 20 µg/L in each sample, blank, or aqueous standard will be produced.
6.7 Secondary standards—using stock solutions, prepare a secondary standard in methanol to contain each pollutant at a concentration of 500 µg/mL For the gases and water soluble compounds (Section 6.6), a concentration of 2.5 mg/mL may be used. (continued)