15
ReducingDiscrimination
Reduced responseof thehighermolecularweight semivolatile compounds canbe causedby
discrimination in the injectionport. In extreme cases response for the last threePAH com-
poundsmaybe lost completely at lower calibration levels. To reduce the effects of discrimina-
tion in the injectionport,we recommendusing a drilledUniliner
®
inlet liner. Because the
column seals into the taper at the bottomof the liner, there is reduced loss of highmolecular
weight compounds and improved response. The drilledUniliner
®
inlet liner has a small hole
drilled at the entrance that allows it toworkwith small diameter columns andElectronic
PressureControl (EPC) injection systems.Whenusing the drilledUniliner
®
liner (Figure 8),
the response of the last threePAHs is significantlyhigher compared to the same analysis done
with a normal splitless sleeve (seeFigure 5). The drilledUniliner
®
is available forAgilent
5890 and6890GCs (see page 19).
Figure8.
TheRtx
®
-5SilMS combinedwith theSiltek
™
drilledUniliner
®
liner exhibits excellent peak shape and response for
the semivolatile compounds listed inUSEPAMethod8270.
1. N-nitrosodimethylamine
2. pyridine
3. methyl methanesulfonate
4. 2-fluorophenol
5. ethyl methanesulfonate
6. phenol-d6
7. phenol
8. aniline
9. bis(2-chloroethyl)ether
10. 2-chlorophenol
11. 1,3-dichlorobenzene
12. 1,4-dichlorobenzene-d4
13. 1,4-dichlorobenzene
14. 1,2-dichlorobenzene
15. benzyl alcohol
16. 2-methylphenol
17. bis(2-chloroisopropyl)ether
18. acetophenone
19. 4-methylphenol/3-methylphenol
20. N-nitroso-di-
n
-propylamine
21. hexachloroethane
22. nitrobenzene-d5
23. nitrobenzene
24. isophorone
25. 2-nitrophenol
26. 2,4-dimethylphenol
27. bis(2-chloroethoxy)methane
28. benzoicacid
29. 2,4-dichlorophenol
30. 1,2,4-trichlorobenzene
31. naphthalene-d8
32. naphthalene
33. 2,6-dichlorophenol
34. 4-chloroaniline
35. hexachloropropene
36. hexachlorobutadiene
37. 4-chloro-3-methylphenol
38. isosafrole
39. 2-methylnaphthalene
40. 1-methylnaphthalene
41. hexachlorocyclopentadiene
42. 1,2,4,5-tetrachlorobenzene
43. 2,4,6-trichlorophenol
44. 2,4,5-trichlorophenol
45. 2-fluorobiphenyl
46. safrole
47. 2-chloronaphthalene
48. 2-nitroaniline
49. 1,4-naphthoquinone
50. dimethylphthalate
51. 1,3-dinitrobenzene
52. 2,6-dinitrotoluene
53. acenaphthylene
54. acenaphthene-d10
55. 3-nitroaniline
56. acenaphthene
57. 2,4-dinitrophenol
58. pentachlorobenzene
59. 4-nitrophenol
60. dibenzofuran
61. 2,4-dinitrotoluene
62. 2,3,4,6-tetrachlorophenol
63. diethyl phthalate
64. fluorene
65. 4-chlorophenyl phenyl ether
66. 4-nitroaniline
67. 4,6-dinitro-2-methylphenol
68. diphenylamine
69. azobenzene
70. 2,4,6-tribromophenol
71. phenacetin
72. 4-bromophenyl phenyl ether
73. hexachlorobenzene
74. pentachlorophenol
75. pentachloronitrobenzene
76. phenanthrene-d10
77. dinoseb
78. phenanthrene
79. anthracene
80. di-
n
-butylphthalate
81. 4-nitroquinoline-1-oxide
82. isodrin
83. fluoranthene
84. benzidine
85. pyrene
86.
p
-terphenyl-d14
87. aramite
88. chlorbenzilate
89. kepone
90. butyl benzyl phthalate
91. benzo(a)anthracene
92. 3,3'-dichlorobenzidine
93. chrysene-d12
94. chrysene
95. bis(2-ethylhexyl)phthalate
96. di-
n
-octyl phthalate
97. benzo(b)fluoranthene
98. benzo(k)fluoranthene
99. benzo(a)pyrene
100. perylene-d12
101. 3-methylcholanthrene
102. indeno(1,2,3-cd)pyrene
103. dibenzo(a,h)anthracene
104. benzo(g,h,i)perylene
30m, 0.25mm ID, 0.25µmRtx
®
-5SilMS (cat.#12723)
Conc.: 24µg/mL inmethylene chloride
(cat.#s: 31618, 31619, 31620, 31621, 31622, 31206,
31062, 31063)
Note: Internal standards at 8ppm
Inj. vol.:
1µL
Inj type:
splitless
Hold time:
0.4 min.
Inlet liner:
drilledUniliner
®
liner, Siltek
™
deactivation (cat# 21054-214.1)
Inj. temp.:
300°C
Carrier gas:
helium (1mL/min. constant flow)
Linear velocity:
34cm/sec.
Oven temp.:
35°C (hold2min.) to260°C@
20°Cmin. (hold0min.), to330°@
6°C/min. (hold1min.)
Det. type:
MS
Transfer line temp.:
280°C
Scan range:
35 to 550amu
Ionization:
EI
Mode:
full scan
GC_EV00576
Website :
E-mail :
TelNo : 03 9762 2034 . . . inAUSTRALIA
