Analyze Picogram-Level Semivolatiles Accurately with GC-MS/MS and EPA Method 8270E

EPA Method 8270E now allows for the use of GC tandem mass spectrometry (GC-MS/MS), which can extend detection levels for semivolatiles down into the low picogram range. Previous versions of the method only allowed GC-MS analysis, which is much less sensitive. Much of the method has remained the same, but the lower levels of detection provide new challenges, including a dynamic calibration range and retention time shifts for reactive compounds. The calibration range is limited by lower levels of detection at the lower end as well as by overloading and MS saturation at the higher end. Using an Rxi-SVOCms column (30 m, 0.25 mm ID, 0.25 µm [cat.# 16623]) and the conditions shown in Figure 1, the upper limit was found to be 0.5 ng on-column. This shifts the typical range of calibration (0.1-100 µg/mL) to concentrations 100x to 1000x lower. Note that a wider range could be obtained by adjusting the split ratio.

Figure 1: The main chromatogram is an analysis of semivolatiles at 100 pg on an Rxi-SVOCms column. A calibration curve was also performed, and the inset figures represent the lowest calibration point for selected compounds.

GC_EV1522

Peaks

	Peaks	tR (min)	Conc. (µg/g)	SRM 1	SRM 2	SRM 3
1.	1,4-Dioxane	2.79	1	88 to 28 @14V	58 to 28 @6V	88 to 57 @8V
2.	N-Nitrosodimethylamine	3.08	1	74 to 42 @16V	74 to 43 @12V	74 to 44 @6V
3.	Pyridine	3.13	1	79 to 51 @26V	52 to 26 @18V	79 to 52 @12V
4.	Ethyl methacrylate	3.62	1	99 to 43 @14V	69 to 41 @6V	99 to 53 @12V
5.	2-Picoline	3.96	1	93 to 65 @18V	66 to 39 @18V	93 to 66 @12V
6.	N-Nitrosomethylethylamine	4.12	1	88 to 42 @16V	88 to 43 @8V	88 to 71 @6V
7.	Acrylamine	4.5	1	71 to 44 @22V	55 to 27 @6V	71 to 55 @6V
8.	Methyl methanesulfonate	4.52	1	80 to 48 @28V	65 to 48 @18V	80 to 65 @8V
9.	2-Fluorophenol	4.73	1	112 to 63 @22V	92 to 63 @14V	112 to 92 @6V
10.	N-Nitrosodiethylamine	5.05	1	102 to 44 @10V	102 to 56 @12V	102 to 85 @6V
11.	Ethyl methanesulfonate	5.51	1	109 to 45 @10V	79 to 48 @34V	109 to 79 @6V
12.	Benzaldehyde	6.01	1	105 to 51 @26V	77 to 51 @14V	105 to 77 @10V
13.	Phenol	6.13	1	94 to 39 @30V	94 to 65 @16V	94 to 66 @10V
14.	Phenol-d6	6.14	1	99 to 69 @18V	71 to 42 @16V	99 to 71 @8V
15.	Aniline	6.17	1	93 to 65 @20V	66 to 39 @18V	93 to 66 @10V
16.	Pentachloroethane	6.26	1	167 to 95 @32V	117 to 82 @30V	167 to 132 @14V
17.	bis-(2-Chloroethyl)ether	6.28	1	93 to 27 @22V	63 to 27 @10V	93 to 63 @6V
18.	2-Chlorophenol	6.35	1	128 to 63 @24V	64 to 38 @12V	128 to 64 @14V
19.	Decane	6.49	1	85 to 41 @12V	71 to 43 @6V	85 to 43 @6V
20.	1,3-Dichlorobenzene	6.61	1	146 to 75 @24V	111 to 75 @12V	146 to 111 @12V
21.	1,4-Dichlorobenzene-d4	6.71	1	150 to 76 @38V	150 to 78 @26V	150 to 115 @14V
22.	1,4-Dichlorobenzene	6.74	1	146 to 75 @24V	111 to 75 @12V	146 to 111 @14V
23.	Benzyl alcohol	6.94	1	108 to 77 @22V	79 to 51 @20V	108 to 79 @12V
24.	1,2-Dichlorobenzene	6.98	1	146 to 111 @12V	111 to 50 @36V	111 to 75 @10V
25.	Indene	7.12	1	116 to 89 @28V	115 to 63 @26V	115 to 89 @16V
26.	2-Methylphenol	7.14	1	108 to 77 @24V	79 to 51 @20V	108 to 80 @8V
27.	2,2′-oxybis(1-chloropropane)	7.2	1	121 to 45 @6V	77 to 51 @12V	121 to 77 @8V
28.	N-Nitrosopyrrolidine	7.34	1	100 to 43 @8V	100 to 55 @6V	100 to 68 @8V
29.	Acetophenone	7.37	1	105 to 51 @26V	77 to 51 @14V	105 to 77 @12V
30.	3- and 4-Methylphenol	7.41	1	107 to 51 @26V	70 to 43 @6V	107 to 77 @12V
31.	N-Nitrosomorpholine	7.42	1	116 to 56 @10V	86 to 56 @6V	116 to 86 @6V
32.	o-Toluidine	7.44	1	107 to 77 @26V	106 to 77 @16V	106 to 79 @8V
33.	Hexachloroethane	7.56	1	201 to 131 @30V	117 to 82 @24V	201 to 166 @12V
34.	Nitrobenzene-d5	7.63	1	128 to 54 @28V	82 to 54 @12V	128 to 82 @12V
35.	Nitrobenzene	7.68	1	123 to 51 @30V	77 to 51 @12V	123 to 77 @10V
36.	N-Nitrosopiperidine	7.94	1	114 to 41 @10V	114 to 84 @6V	114 to 97 @6V
37.	Isophorone	8.12	1	138 to 82 @8V	82 to 39 @12V	82 to 54 @6V
38.	2-Nitrophenol	8.25	1	139 to 81 @12V	109 to 81 @8V	139 to 109 @8V
39.	2,4-Dimethylphenol	8.36	1	122 to 77 @26V	107 to 77 @14V	122 to 107 @12V
40.	O,O,O-Triethyl phosphorothioate	8.51	1	198 to 114 @12V	121 to 65 @10V	198 to 121 @8V
41.	Benzoic acid	8.53	1	122 to 77 @20V	105 to 77 @10V	122 to 105 @8V
42.	Bis(2-chloroethoxy)methane	8.55	1	93 to 63 @6V	63 to 26 @36V	63 to 27 @12V
43.	Phentermine	8.64	1	134 to 91 @20V	58 to 42 @22V	134 to 115 @12V
44.	2,4-Dichlorophenol	8.68	1	162 to 63 @24V	98 to 63 @8V	162 to 98 @12V
45.	1,2,4-Trichlorobenzene	8.84	1	180 to 109 @24V	145 to 109 @10V	180 to 145 @12V
46.	Naphthalene-d8	8.91	1	136 to 84 @20V	136 to 108 @18V	136 to 134 @14V
47.	Naphthalene	8.97	1	129 to 103 @14V	128 to 78 @20V	128 to 102 @16V
48.	a-Terpineol	9.04	1	136 to 93 @10V	121 to 93 @8V	136 to 121 @8V
49.	4-Chloroaniline	9.09	1	127 to 65 @20V	65 to 39 @12V	127 to 100 @10V
50.	2,6-Dichlorophenol	9.11	1	164 to 63 @26V	162 to 63 @26V	162 to 126 @8V
51.	Hexachloropropene	9.15	1	215 to 119 @18V	213 to 119 @18V	215 to 121 @18V
52.	Hexachlorobutadiene	9.23	1	260 to 190 @26V	225 to 190 @14V	260 to 225 @12V
53.	Quinoline	9.6	1	129 to 76 @26V	102 to 76 @12V	129 to 102 @16V
54.	Caprolactam	9.7	1	113 to 56 @10V	85 to 67 @6V	113 to 85 @6V
55.	N-Nitrosodibutylamine	9.76	1	116 to 74 @8V	84 to 56 @14V	116 to 99 @6V
56.	1,4-Phenylenediamine	9.77	1	108 to 80 @20V	80 to 53 @12V	108 to 81 @10V
57.	4-Chloro-3-methylphenol	10.04	1	142 to 77 @26V	107 to 77 @12V	142 to 107 @12V
58.	Isosafrole I	10.16	1	162 to 104 @12V	131 to 103 @8V	162 to 131 @12V
59.	2-Methylnaphthalene	10.28	1	141 to 89 @30V	115 to 89 @16V	141 to 115 @16V
60.	1-Methylnaphthalene	10.46	1	141 to 89 @30V	115 to 89 @14V	141 to 115 @16V
61.	Hexachloropentadiene	10.59	1	272 to 237 @12V	237 to 119 @20V	237 to 143 @22V
62.	1,2,4,5-Tetrachlorobenzene	10.61	1	216 to 108 @36V	179 to 143 @8V	216 to 181 @14V
63.	Isosafrole II	10.73	1	162 to 104 @12V	131 to 103 @10V	162 to 131 @12V
64.	2,3-Dichloroaniline	10.83	1	163 to 90 @18V	161 to 90 @16V	161 to 99 @18V
65.	2,4,6-Trichlorophenol	10.83	1	196 to 97 @24V	132 to 97 @10V	160 to 97 @16V
66.	2,4,5-Trichlorophenol	10.88	1	196 to 97 @24V	132 to 97 @10V	196 to 132 @12V
67.	2-Fluorobiphenyl	10.99	1	172 to 151 @22V	172 to 170 @22V	172 to 171 @12V
68.	Safrole	11.16	1	162 to 77 @30V	131 to 103 @10V	162 to 127 @16V
69.	2-Chloronaphthalene	11.2	1	162 to 77 @32V	127 to 77 @16V	162 to 127 @16V
70.	Biphenyl	11.2	1	153 to 126 @32V	154 to 115 @24V	154 to 152 @22V
71.	1-Chloronaphthalene	11.25	1	162 to 77 @30V	127 to 77 @16V	162 to 127 @16V
72.	o-Nitroaniline	11.41	1	138 to 65 @22V	108 to 80 @8V	138 to 92 @12V
73.	Diphenyl ether	11.42	1	170 to 141 @16V	141 to 115 @14V	170 to 142 @10V
74.	1,4-Naphthoquinone	11.56	1	158 to 102 @14V	102 to 76 @12V	158 to 130 @8V
75.	1,2-Dinitrobenzene	11.7	1	168 to 75 @20V	122 to 75 @12V	168 to 122 @8V
76.	1,3-Dinitrobenzene	11.83	1	168 to 75 @22V	76 to 50 @10V	168 to 122 @8V
77.	Diphenyl phthalate	11.83	1	163 to 77 @20V	163 to 92 @24V	163 to 133 @8V
78.	1,6-Dinitrotoluene	11.91	1	165 to 63 @20V	148 to 90 @10V	165 to 148 @8V
79.	Acenaphthylene	11.98	1	152 to 76 @36V	152 to 102 @26V	152 to 126 @24V
80.	1,4-Dinitrobenzene	11.99	1	168 to 51 @14V	76 to 63 @6V	168 to 63 @26V
81.	3-Nitroaniline	12.21	1	138 to 65 @20V	92 to 65 @8V	138 to 92 @12V
82.	Acenaphthene-d10	12.24	1	164 to 160 @32V	162 to 160 @18V	164 to 162 @14V

	Peaks	tR (min)	Conc. (µg/g)	SRM 1	SRM 2	SRM 3
83.	Acenaphthene	12.32	1	153 to 77 @38V	153 to 126 @36V	154 to 127 @34V
84.	2,4-Dinitrophenol	12.41	1	184 to 107 @10V	154 to 79 @12V	184 to 154 @6V
85.	4-Nitrophenol	12.57	1	139 to 81 @14V	109 to 81 @8V	139 to 109 @6V
86.	Pentachlorobenzene	12.6	1	250 to 142 @38V	215 to 179 @10V	250 to 215 @16V
87.	2,4-Dinitrotoluene	12.66	1	165 to 63 @22V	89 to 63 @12V	165 to 119 @6V
88.	Dibenzofuran	12.66	1	168 to 139 @22V	139 to 63 @30V	139 to 89 @18V
89.	1-Naphthylamine	12.81	1	143 to 115 @22V	115 to 89 @16V	143 to 116 @10V
90.	2,3,5,6-Tetrachlorophenol	12.83	1	234 to 133 @26V	232 to 131 @26V	232 to 168 @12V
91.	2,3,4,6-Tetrachlorophenol	12.91	1	234 to 131 @24V	232 to 133 @26V	232 to 168 @12V
92.	2-Naphthylamine	12.97	1	143 to 115 @24V	115 to 89 @16V	143 to 116 @10V
93.	Diethyl Phthalate	13.21	1	177 to 149 @8V	149 to 65 @20V	149 to 93 @12V
94.	Hexadecane	13.29	1	99 to 41 @14V	85 to 43 @6V	99 to 57 @6V
95.	Fluorene	13.31	1	167 to 166 @14V	165 to 115 @24V	165 to 139 @26V
96.	Zinophos	13.36	1	143 to 79 @10V	107 to 52 @20V	107 to 79 @14V
97.	5-Nitro-o-toluidine	13.37	1	152 to 77 @24V	106 to 77 @12V	152 to 106 @10V
98.	4-Chlorophenyl phenyl ether	13.37	1	204 to 77 @22V	141 to 115 @14V	204 to 141 @12V
99.	4-Nitroaniline	13.37	1	138 to 80 @18V	108 to 80 @10V	138 to 108 @8V
100.	4,6-Dinitro-2-methylphenol	13.45	1	198 to 121 @10V	168 to 121 @6V	198 to 168 @6V
101.	Diphenylamine	13.6	1	169 to 66 @22V	169 to 77 @30V	170 to 66 @22V
102.	Azobenzene	13.67	1	182 to 77 @12V	77 to 51 @14V	182 to 105 @6V
103.	2,4,6-Tribromophenol	13.77	1	332 to 143 @34V	330 to 141 @36V	330 to 222 @20V
104.	Sulfotepp	14	1	322 to 146 @24V	202 to 146 @10V	322 to 202 @10V
105.	1,3,5-Trinitrobenzene	14.14	1	213 to 74 @38V	213 to 120 @22V	213 to 167 @8V
106.	Diallate 1	14.2	1	234 to 150 @16V	86 to 43 @6V	234 to 192 @12V
107.	Phorate	14.22	1	121 to 47 @26V	75 to 47 @8V	121 to 65 @8V
108.	Phenacetin	14.25	1	179 to 109 @14V	108 to 80 @12V	179 to 137 @8V
109.	4-Bromophenyl phenyl ether	14.31	1	250 to 141 @16V	141 to 115 @12V	248 to 141 @14V
110.	Diallate 2	14.37	1	234 to 150 @16V	86 to 43 @6V	234 to 192 @10V
111.	Hexachlorobenzene	14.37	1	288 to 216 @26V	249 to 214 @12V	284 to 249 @14V
112.	Dimethoate	14.51	1	125 to 47 @14V	93 to 63 @8V	125 to 79 @8V
113.	Atrazine	14.7	1	215 to 58 @10V	200 to 122 @8V	215 to 200 @8V
114.	Pentachlorophenol	14.77	1	270 to 169 @22V	228 to 165 @14V	266 to 167 @22V
115.	4-Aminobiphenyl	14.79	1	169 to 141 @22V	168 to 141 @8V	168 to 167 @10V
116.	Pentachloronitrobenzene	14.81	1	295 to 237 @14V	237 to 143 @20V	295 to 265 @8V
117.	Propyzamide	15	1	254 to 191 @16V	173 to 145 @14V	254 to 226 @10V
118.	Octadecane	15.1	1	99 to 41 @14V	85 to 43 @6V	99 to 57 @6V
119.	Phenanthrene-d10	15.1	1	188 to 160 @20V	184 to 154 @32V	184 to 156 @22V
120.	Phenanthrene	15.16	1	178 to 151 @32V	176 to 150 @20V	178 to 152 @20V
121.	Dinoseb	15.21	1	240 to 117 @24V	163 to 116 @14V	240 to 211 @8V
122.	Disulfoton	15.22	1	97 to 65 @16V	88 to 60 @6V	97 to 79 @12V
123.	Anthracene	15.26	1	178 to 151 @32V	177 to 151 @18V	178 to 152 @18V
124.	Carbazole	15.6	1	167 to 139 @24V	166 to 140 @14V	167 to 166 @12V
125.	Methyl Parathion	15.95	1	263 to 79 @24V	125 to 47 @12V	263 to 109 @10V
126.	di-n-Butyl phthalate	16.41	1	149 to 65 @20V	149 to 93 @14V	149 to 121 @12V
127.	4-Nitroquinoline-N-oxide	16.69	1	190 to 77 @20V	101 to 75 @10V	190 to 160 @8V
128.	Ethyl Parathion	16.73	1	291 to 81 @26V	109 to 81 @10V	291 to 109 @10V
129.	Methapyrilene	16.9	1	190 to 97 @14V	97 to 53 @16V	190 to 157 @8V
130.	Isodrin	17.19	1	261 to 191 @28V	193 to 123 @28V	261 to 226 @16V
131.	Fluoranthene	17.47	1	202 to 152 @30V	200 to 174 @22V	202 to 176 @26V
132.	Benzidine	17.8	1	184 to 130 @26V	184 to 156 @18V	184 to 166 @16V
133.	Pyrene-d10	17.84	1	212 to 208 @36V	212 to 210 @20V	0
134.	Pyrene	17.88	1	200 to 149 @34V	200 to 150 @26V	200 to 174 @24V
135.	p-Terphenyl-d14	18.3	1	244 to 226 @18V	244 to 240 @22V	244 to 242 @14V
136.	Aramite 1	18.33	1	319 to 123 @10V	175 to 107 @14V	319 to 185 @6V
137.	Aramite 2	18.49	1	319 to 107 @36V	185 to 63 @12V	319 to 185 @6V
138.	p-Dimethylaminoazobenzene	18.57	1	225 to 120 @10V	120 to 77 @16V	225 to 148 @6V
139.	Chlorobenzilate	18.71	1	251 to 111 @30V	139 to 111 @12V	251 to 139 @12V
140.	Famphur	19.17	1	218 to 109 @14V	125 to 47 @14V	125 to 79 @6V
141.	3,3′-Dimethylbenzidine	19.21	1	212 to 180 @22V	211 to 195 @16V	211 to 196 @8V
142.	Kepone	19.24	1	272 to 237 @12V	237 to 119 @24V	237 to 143 @22V
143.	Benzyl butyl phthalate	19.31	1	206 to 149 @8V	149 to 65 @20V	149 to 121 @10V
144.	Bis(2-ethylhexyl) adipate	19.55	1	129 to 55 @14V	111 to 83 @6V	129 to 83 @8V
145.	2-Acetylaminofluorene	19.69	1	223 to 180 @26V	181 to 152 @34V	223 to 181 @10V
146.	Chrysene-d12	20.23	1	240 to 212 @22V	240 to 236 @30V	240 to 238 @14V
147.	Benz[a]anthracene	20.23	1	228 to 202 @24V	226 to 199 @36V	226 to 200 @28V
148.	3,3′-Dichlorobenzidine	20.25	1	252 to 154 @26V	252 to 181 @24V	252 to 182 @20V
149.	4,4′-Methylenebis(2-chloroaniline)	20.28	1	266 to 195 @28V	231 to 195 @16V	266 to 231 @12V
150.	Chrysene	20.3	1	228 to 202 @22V	226 to 200 @28V	228 to 201 @36V
151.	Bis(2-ethylhexyl) phthalate	20.49	1	167 to 149 @8V	149 to 93 @16V	149 to 121 @14V
152.	6-Methylchrysene	21.19	1	242 to 226 @28V	239 to 213 @26V	239 to 237 @32V
153.	Di-n-octyl phthalate	21.86	1	149 to 65 @22V	149 to 93 @16V	149 to 121 @12V
154.	7,12-Dimethylbenz[a]anthracene	22.45	1	256 to 239 @38V	241 to 226 @14V	256 to 241 @12V
155.	Benzo[b]fluoranthene	22.46	1	252 to 226 @24V	250 to 223 @38V	250 to 224 @24V
156.	Benzo[k]fluoranthene	22.53	1	252 to 226 @22V	250 to 223 @38V	250 to 224 @26V
157.	Benzo[a]pyrene	23.21	1	252 to 226 @26V	250 to 223 @38V	250 to 224 @26V
158.	Perylene-d12	23.33	1	264 to 236 @24V	264 to 260 @34V	264 to 262 @20V
159.	3-Methylcholanthrene	24.16	1	268 to 252 @32V	252 to 226 @22V	268 to 253 @14V
160.	Dibenz(a,h)acridine	25.55	1	279 to 252 @34V	278 to 250 @24V	278 to 275 @36V
161.	Dibenz[a,j]acridine	25.74	1	279 to 250 @38V	278 to 250 @26V	279 to 277 @30V
162.	Indeno[1,2,3-cd]pyrene	26.16	1	276 to 250 @30V	276 to 274 @34V	138 to 125 @12V
163.	Dibenz[a,h]anthracene	26.24	1	278 to 252 @26V	139 to 113 @14V	139 to 126 @8V
164.	Benzo[ghi]perylene	26.88	1	276 to 274 @38V	138 to 124 @28V	138 to 125 @12V

Conditions

Column	Rxi-SVOCms, 30 m, 0.25 mm ID, 0.25 µm (cat.# 16623)
Standard/Sample
	SVOC MegaMix 150 kit (cat.# 31907)
	SV internal standard mix (cat.# 31206)
	Acid surrogate mix (4/89 SOW) (cat.# 31063)
	Revised B/N surrogate mix (cat.# 31888)
Diluent:	Dichloromethane
Conc.:	1 µg/mL (0.1 ng on-column)
Injection
Inj. Vol.:	1 µL split (split ratio 10:1)
Liner:	Topaz 4.0 mm ID single taper inlet liner w/ wool (cat.# 23303)
Inj. Temp.:	250 °C
Oven
Oven Temp.:	40 °C (hold 1 min) to 280 °C at 12.4 °C/min to 330 °C at 3.3 °C/min (hold 3.65 min)
Carrier Gas	He, constant flow
Flow Rate:	1.2 mL/min

Detector	TSQ8000
Transfer Line Temp.:	280 °C
Analyzer Type:	Quadrupole
Source Temp.:	330 °C
Quad Temp.:	180 °C
Electron Energy:	70 eV
Solvent Delay Time:	2 min
Tune Type:	PFTBA
Ionization Mode:	EI
Instrument	Thermo Trace GC
Sample Preparation	Solutions were mixed and diluted to 1 ppm or lower with dichloromethane in amber 2 mL, 9 mm short-cap, screw-thread vials (cat.# 21143) and sealed with 2.0 mL, 9 mm short-cap, screw-vial closures (cat.# 23842).
Notes	The compounds in the inserts are at lower concentrations than the full chromatogram and are showing specific transitions as noted in the inserts. The SVOC MegaMix 150 kit (cat.# 31907) contains one ampul each of the following standards: • 8270 MegaMix (cat.# 31850) • SVOC additions standard (cat.# 31909) • Appendix IX mix #1, revised (cat.# 32459) • Methapyrilene (cat.# 32460) • Appendix IX mix #2 (cat.# 31806) • Benzoic acid (cat.# 31879)

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The second challenge presented by GC-MS/MS analysis of semivolatiles using EPA Method 8270E is the response stability of reactive compounds, such as pyridine, benzoic acid, and acrylamide. These compounds exhibit a shift in retention time across different concentrations, which can make detection challenging when using SRM windows. As the concentration of active analytes decreases, the retention time increases (Figure 2). We found that the best concentration range for these compounds is 1-10 ng on-column.

In summary, GC-MS/MS is a great technique for detecting picograms on-column, and it significantly extends the sensitivity range for semivolatile analysis using EPA Method 8270E, albeit with some caveats. Analysts must be aware of calibration range changes, and they must also watch for retentions time shifts for reactive compounds and adjust SRM windows accordingly, if necessary.

Figure 2: Pyridine retention time shifts with decreased concentration.