GC-MS Analysis of Polychlorinated Biphenyl Congeners Using a New
Capillary GC ColumnFrank L. Dorman, Gary B. Stidsen, Chris M.
English and Lydia NolanRestek Corporation, Bellefonte, PA
Jack CochranLECO Corporation, Las Vegas, NV
Abstract• The analysis of polychlorinated biphenyls (PCB’s) by GC can be a
very challenging analysis. Numerous researchers have demonstrated various separations on the common commercially available GC stationary phases, but all of these have had limitations when it comes to the separation of all 209 possible PCB congeners. While it may be argued that the complete separation of all 209 possible congeners is not necessary, separation of the environmentally significant and the toxic congeners is important.
• The separation requirements for the analysis of PCB congeners differ considerably depending on the type of detector used. Separation needs when using a mass spectrometer are different then when using standard GC detectors.
• This presentation will discuss the separation needs for PCB congeners when using a mass spectrometer, and demonstrate an improved separation of PCB congeners, using a new capillary stationary phase developed for this purpose.
Experiment• Determine retention times for all 209 PCBs on
a new low-bleed capillary column – AccuStandard 9 mixtures– Hexachlorobenzene for relative retention times
• Analyze mix of Aroclors 1221:1242:1254:1262– 1:2:2:2 ratio– Show chromatogram with congeners labeled
• GC-MS results obtained using a time-of-flight mass spectrometer to allow for possible spectral deconvolution
GC-TOFMS Conditions• Gas Chromatography
– One microliter splitless 250°C, 60 sec valve – 60 m x 0.18 mm x 0.18 µm Restek Rtx-PCB column
• Constant flow helium, 1.5 mL/minute• 70°C (1 min), 50°/min to 120°, 3°/min to 360° (1 min)
• Mass Spectrometry LECO Pegasus III– Source temperature: 225°C– Electron ionization: 70 eV– Stored mass range: 120 to 520 u– Acquisition rate: 5 spectra/sec
Aroclor Mix Chromatogram• Overlaid ion chromatograms are plotted
– For example, hexachlorobiphenyl is 360– Peaks are labeled with congener numbers
• Text size and format is only for space and not meant to indicate anything about PCBs, except:
• European indicator congeners are in red
• Chromatograms are not to one scale– Each panel is adjusted so most of the PCB
peaks can be seen
1
2
3
4+10
9 7
6
5
8
19
18
17
12 27
13
24
16 32
15
3423
54 29
26
25
31 28
33
51
45
22
46 43
52
48
49
53 20
47
75
44
59
4271
35
417296
103
64
40
37
67 102
95
74
70
94 57 98
639376
91
66
55
92
89+84
101
99
60
11983
12586
97
87
154
110
85
115
136117
56
151
135 82
144
147+149
77139
124123+109
134133
118153
114
122
146
131
132 179
141
176
105
137
130164
138
163
129
158
187
175
183
166
185
174
128
202167
177
201171
172173 197
178
156157
180
193 200
191 198
199
170
196
203
190
208
207 189
195
194
205
206
Important Congener Separations
• European indicator PCBs
• May coelute on 5% phenyl methylsiliconeand other column phases
31 28
33Trichlorobiphenyls
20
153
132
Hexachlorobiphenyls
138
163
Hexachlorobiphenyls
Table Key• Congener classification according to their significance in
Aroclors 1242, 1254, or 1260– Bold Underline: Congener > 1.0 Wt%
– Bold: Congener 0.05 to 1.0 Wt%
– Italics: Trace or undetected congener
• Congener naming according to Guitart et al. by chlorine positions– 107: 234-35– 108: 2346-3– 109: 235-34
– 199: 2345-2356– 200: 23456-236– 201: 2346-2356
• RRT is relative retention time
• Coelutions of significance where MS won’t help are
2110.92109.32093.32088.12067.32061.12053.31993.51963.31953.31894.31882.31849.31815.31808.31679.71678.11642.11601.31403.3
RT (sec)
1.083935.183241.082935.152131.074834.893271.072134.802121.061534.463171.058234.352111.054334.223181.023633.223301.007932.722141.003032.553190.972731.57280.966531.37250.949630.82260.932130.26270.928530.14290.862528.002100.861727.97240.843227.37130.822226.69120.720623.3911RRTRT (min)Cl#PCB#
2374.32364.32349.52313.32312.72312.92309.52303.52290.72286.52252.72239.32237.12202.72188.92187.32176.12158.92148.72135.1
RT (sec)
1.218939.574731.214039.403221.206439.164451.187738.563201.187438.543211.187438.554511.185838.493331.182838.393281.176238.183311.173838.114531.156737.543251.149837.323261.148637.284501.130936.713291.123736.484541.123436.453231.117336.273341.108435.982151.103335.813321.096335.58316RRTRT (min)Cl#PCB#
2535.72527.92521.52506.72501.32487.32461.32452.92450.72451.32448.52444.72440.32426.52417.32406.92398.92397.72391.52374.5
RT (sec)
1.302042.264411.297842.133351.294742.024711.287041.784421.284241.694591.277241.454441.263741.023381.259840.883391.258640.844621.258440.854751.257140.814651.255240.754471.252940.6751041.245840.444491.241240.294481.235940.114521.231739.983361.231239.964431.227939.864691.219339.58446RRTRT (min)Cl#PCB#
2657.52653.92650.92646.12646.12637.92635.92618.92614.72613.52594.12589.12581.92581.32569.92561.92560.52552.32545.12542.1
RT (sec)
1.364644.295951.363044.2351211.361044.184631.358744.104761.358644.105931.354443.965981.353343.934611.344643.6551021.342643.584581.342043.564671.331943.234571.329743.155941.325543.0351001.325443.023371.319542.834401.315342.704641.315042.674681.310542.5451031.306742.425961.305242.37472RRTRT (min)Cl#PCB#
2802.32798.92776.72776.12772.92757.32751.52751.52750.92745.92743.72726.52723.32709.72695.72688.72678.32675.72667.92658.9
RT (sec)
1.438846.7151191.437046.6561521.425846.284601.425846.2751501.423846.215991.415745.9551131.412845.864561.412545.865901.412445.8551011.410045.775841.408745.735891.399945.445921.398445.394551.391745.164801.384244.934661.380544.815911.375244.644701.374244.5961551.369944.464741.365644.31588RRTRT (min)Cl#PCB#
2906.72895.72889.12883.52878.92877.32871.12870.32868.32867.72855.52841.92835.52828.92825.92821.52817.72812.12811.32807.5
RT (sec)
1.492548.4451101.486948.2651201.483348.155851.480648.0651151.478047.9851171.477347.9661361.474647.8551111.473747.844781.472847.805871.472247.7961541.466547.5951161.459147.364791.456347.2661481.452447.155971.450947.1061451.448847.0251081.446746.965861.444046.8751121.443846.8551251.441646.79583RRTRT (min)Cl#PCB#
3027.53023.13018.93018.53011.53011.33009.53005.32990.52988.92981.32980.32972.32968.32966.32949.12948.32937.32929.12927.7
RT (sec)
1.554950.4661421.552150.3861331.550050.3151061.549850.3161341.546750.1971881.546250.1951091.545250.1651231.543050.0951071.535949.8461431.534449.8151241.530749.6961391.530649.6761401.526149.544771.524149.4761491.523149.4461471.514249.1561441.513949.145821.508248.9661351.503948.8261511.503048.79481RRTRT (min)Cl#PCB#
3171.13168.73157.73157.13150.73140.93137.53125.73109.33094.13077.13076.13072.53060.33060.13050.33044.13040.73034.33032.5
RT (sec)
1.628352.8561641.626752.8161301.621252.6351271.621152.6271861.617752.5161371.612652.3551051.610952.2971761.605052.1061411.596651.8271791.588751.5761321.580051.2861531.579451.2751141.578051.2161681.571251.0061611.571051.0051221.566350.8461461.562850.7361651.561250.6871841.558050.5761311.557050.545118RRTRT (min)Cl#PCB#
3328.93322.73321.13307.73307.93295.93293.33290.33277.33264.13243.33221.13210.53209.73208.53203.93198.93196.73191.73187.7
RT (sec)
1.709155.4871811.706055.3861671.705055.3582021.698455.1371741.698455.1361281.692754.9361621.690954.8971851.689354.8451261.682854.6261591.675954.4061661.665454.0671831.654053.6871871.648253.5171751.648053.4971821.647353.4861581.645053.4061291.642953.3161601.641153.2861631.638953.1961381.636853.137178RRTRT (min)Cl#PCB#
3569.33564.73564.73546.93539.93534.33456.53447.73437.53432.13430.13415.33414.73403.13383.13379.73366.13353.93352.33348.5
RT (sec)
1.832859.4982031.830459.4181961.830259.4171901.821259.1271701.817759.0081991.814858.9081981.774757.6171911.770057.4682001.765157.2971931.762357.2071801.761157.1761571.753556.9261561.753456.9171921.747456.7271721.737156.3981971.735456.3371731.728456.1071711.722055.9082041.721055.8782011.719455.817177RRTRT (min)Cl#PCB#
3952.93872.33791.53766.93692.93683.33676.53643.73583.5
RT (sec)
2.029565.88102091.988464.5492061.946863.1982051.934262.7881941.896261.5581951.891161.3971891.887661.2892071.870860.7392081.839959.726169RRTRT (min)Cl#PCB#
Conclusions• Greater than 140 Aroclor PCBs can be
determined with the new column and mass spectrometry
• The seven European indicator PCBs can be determined individually
• Spectral deconvolution available with TOFMS allows qualitative identification for coeluting PCBs
