ADV01-05_1-298

• 14 •

800-356-1688 •

www.restek.com

2005 vol. 1

A high sample throughput is important to most

analysts, and is essential to those in environ-

mental laboratories. Chromatographers follow-

ing US EPA methods 8270, 625, or 525, or other

methods for equivalent lists of semivolatile

organic pollutants, now can take advantage of

advances in mass spectrometer and GC column

technology, to reduce analytical time and

increase sample throughput while also obtaining

good lifetimes from their columns.

The new generation of high sensitivity mass

spectrometers enables analysts to reduce the

amount of sample injected onto the column. In

analyses of semivolatiles, this has lead to using

split injections and columns having smaller

internal diameter, resulting in shorter analysis

times. Split injection contributes to good chro-

matographic resolution, but also helps improve

sensitivity by reducing the degradation of acidic

and basic compounds in the hot injection port.

Further, because less sample is transferred onto

the column in split injections, transfer of non-

volatile contaminants from the extracts is mini-

mized, and column lifetime is prolonged.

In our laboratories, we have been evaluating

various combinations of column length, ID, and

film thickness for suitability for shortening

analysis time while meeting the resolution

requirements of the various methods. The latest

product of our research is the 20m, 0.18mm ID,

0.36µm film Rtx

-5Sil MS column. Figure 1

shows the results of an analysis on this new

column. Under the conditions listed, resolution

of these 89 compounds meets the resolution cri-

teria of method 8270, 625, or 525. A split injec-

tion was used to obtain Figure 1, but the column

also can be used with splitless injections.

The 20m, 0.18mm ID, 0.36µm film Rtx

-5Sil MS

column is the latest product of our application

lab chemists' continuing efforts to combine rapid

analysis with good column lifetime, and give you

the best available column for analyzing semi-

volatile pollutants. To discuss this application,

call our technical support staff at 800-356-1688

or 814-353-1300, ext. 4, or contact your Restek

representative.

Fast GC/MS Analysis of Semivolatile Organic

Compounds

Using a 0.18mm ID / 0.36µm Film Rtx

-5Sil MS Column

by Gary Stidsen, GC Columns Marketing Manager

•Meets resolution and response factors for many methods, including EPA Method 8270.

•Split injections and thick phase film help prolong column life when analyzing dirty extracts.

• Low bleed, thermally stable.

•Column and method optimized for conventional scanning detectors, such as Agilent 5973.

GC_EV00757

1. N-nitrosodimethylamine

2. pyridine

3. 2-fluorophenol

peaks 4-63: see page 19

64. 4-bromophenyl phenyl ether

65. hexachlorobenzene

66. pentachlorophenol

67. phenanthrene-d10

68. phenanthrene

69. anthracene

70. carbazole

71. di-

-butylphthalate

72. fluoranthene

73. benzidine

74. pyrene

75.

-terphenyl-d14

76. butyl benzyl phthalate

77. bis(2-ethylhexyl)adipate

78. benzo(a)anthracene

79. chrysene-d12

80. bis(2-ethylhexyl)phthalate

81. chrysene

82. di-

-octyl phthalate

83. benzo(b)fluoranthene

84. benzo(k)fluoranthene

85. benzo(a)pyrene

86. perylene-d12

87. indeno(1,2,3-cd)pyrene

88. dibenzo(a,h)anthracene

89. benzo(ghi)perylene

Figure1

89 semivolatile pollutants, surrogates, and internal standards separated in less than 18

minutes on a 20m, 0.18mm ID, 0.36µm film Rtx®-5Sil MS column.

Enlarged area—see page 19.

Column:

Rtx

-5Sil MS, 20m, 0.18mm ID, 0.36µm (cat.# 557810)

Sample:

US EPA Method 8270D analytes, 10ppm each (10ng on column); 8270 MegaMix

™

(cat.# 31850); Benzidine (cat.# 31441); Benzoic Acid (cat.# 31415); 2,4-

Dinitrophenol (cat.# 31291); Acid Surrogate Mix (4/89 SOW) (cat.# 31063); B/N

Surrogate Mix (4/89 SOW) (cat.# 31062)

Inj.:

1.0µL, splitless, 4mm ID gooseneck splitless inlet liner (cat.# 20798), splitless

hold time 0.20 min., pressure pulse 0.15 min. @ 30psi

GC:

Agilent 6890

Inj. temp.:

250°C

Carrier gas:

helium, constant flow

Flow rate:

1.2mL/min.

Oven temp.:

50°C(hold 0.5 min.) to 330°C @ 18°C/min. (hold 3 min.)

Det.:

Agilent 5973 GC/MS

Transfer line

temp.:

280°C

Scan range:

35-550 amu

Solvent Delay:

1 min.

Tune:

DFTPP

Ionization: