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Environmental
NewRxi™-1 ms Capillary GC Column
For Low Level GC/MS Analyses
By Robert Freeman, Environmental Innovations Chemist
• Inert, low-bleed column for reliable result s.
Save time - analyze acidic and basic compounds under the same conditions.
Guaranteed reproducible performance, column to column.
The second column in our new Rxi" GC column
line - the Rxi™-lms column - will provide the
same outstanding performance as the Rxi™-Sms
column, with equally superior inertness, ultr a-low
bleed, and excellent batch to batch reproducibility.
Our first test for this 100% dimethylpolysiloxane
phase column was an analysis of a comple x mix­
ture of semivolatile organic compounds . The
extensive target list was comprised of many classes
of compounds including chloro acet ani lides,
chlorotriazines, tria zinon es, uracils, polcyclic aro­
matic hydrocarbons, and phthalates. Figure 1
shows peak shape and selectivity are equally good
for all of these diverse compounds, and all are elut­
ed in an acceptable analysis time .
Excellent Inertness
In addition to analyzing these compounds, we
analyzed an acidic compound (2,4-dinitrophenol)
and a basic compound (pyridine), each at O.5ng on
column, to assess column inertness. Column activ­
ity reveals itself through poor response and peak
tailing for such active compounds, and these two
compounds present both varying difficulties in a
GC/MS analysis and differing modes of degrad a­
tion . Figure 2 shows the excellent peak shapes and
respons es for these compounds on th e 30m x
0.25mm !D, 0.25flm film column.
Pheno ls are notorious for breakdown and peak
tailing, caused by interaction with the surface of an
active inlet liner or an active column. Nitrophenols
and pentachlorphenol, for exampl e, very often
exhibit poor peak shape and /or poor response.
Figure 3 shows the 30m x 0.2Smm !D, 0.2Sflm
Rxi™_lms column provi des very good peak
shapes for pheno ls. Peak responses are well above
method requirements.
Ultra-Low Bleed
In addition to excellent inertness, Rxi H I -l ms
columns exhibit very low bleed. Figure 4 is focused
on the end of the chromatogram for semivolatiles.
At 330°C, bleed is much lower than the signals for
O.5ngof target ana lytes. This exceptional signal-to­
no ise differential for late eluting compounds
assures better detection limits.
Figure 1 Excellent select ivity and peak shapes for common
drinking water semivolatiles at lOng, using an Rxi™-lms column.
1. 2-fluorophenol (surr.) 21. 2-naphthalenamine 42. metolachlor
2. bis(2-chloroethyl)ether 22. 5-nitro-o-toluidine 43.fluoranthene
3. phenol-d6(surr.) 23. diethylphthalate 44. pyrene
4. 1,4-dichlorobenzene-d4 24.fluorene 45. butachlor
(int. std.) • 25. propachlor 46. p-terphenyl-d14(surr.)
5. nitrobenzene-d5(surr.) 26. diphenylamine 47. p-dimethylaminoazobenzene
6. naphthalene-d8 (int. std.) • 27. 2,4,6-tribromophenol (surr.) 48. benzylbutyl phthalate
7. naphthalene 28.simazine 49. 2-acetylaminofluorene
8. l- rnethylnaphthalene 29.prometon 50. bis(2-ethylhexyl)adipate
9. 2-methylnaphthalene 30. atrazine 51. benzo(a)anthracene
10. hexachlorocyclopentadiene 31. hexachlorobenzene 52. chrysene-d12(int. std.) •
11. EPTC 32. 4-aminobiphenyl 53. chrysene
12. 2-fluorobiphenyl (surr.) 33. terbacil 54. bis(2-ethylhexyl)phthalate
13. 2,6-dinitrotoluene 34. phenanthrene-dl0 (int. std.) • 55. di-n-octylphthalate
14. dimethylphthalate 35. phenanthrene 56. benzo(b)fluoranthene
15. acenaphthylene 36. anthracene 57. benzo(k)fluoranthene
16. acenaphthene-dl fl (int. std.) • 37. metribuzin 58. benzo(a)pyrene
17. acenaphthene 38. acetochlor 59.perylene-d12(int. std.) •
18. 2,4-dinitrotoluene 39. alachlor 60. indeno(1,2,3-cd)pyrene
19. I-naphthalenamine 40. bromacil 61. dibenzo(a,h)anthracene
20. molinate 41. di-n-butylphthalate 62. benzo(ghi)perylene
2,3
13-36
6 4445 51,:%53
4 7 9 12
3~1 431/
46 50
8 381 42 4/ 8 54 55
57 59
1
10 37 56 58
40 6~rt
II !
15.00 11,00
GC EV00833
Column: Rxi~-lms , 30m, 0.25mm 10,0.251lm (cat.# 13323)
Sample: US EPA Method525.2 mix: custom525.2calibrationmix,
SVInternal Standard Mix (cat.# 31206),
BIN Surrogate Mix(4/89 SOW) (cat.# 31024),
Acid Surrogate Mix (4/89SOW) (cat.# 31025)
Inj.: 1.01lL, lOllg/ mLeach analyte (internal standards lOOllg/ mL), split (10:1)
4mmDnlled Uniliner" inlet liner (holeat bottom) (cat.# 20756)
Instrument: Agllent 6890
Inj. temp.: 250' C
Carrier gas: helium, constant flow
Flow rate: 1.2mL/min.
Oven temp.: 50'C(hold 1 min.)to 265' C@ 20' C/ min., to 330'C @ 6'Cmin. (hold1 min.)
Del.: Agilent 5973MSD
Transfer line
temp.: 280'C
Scanrange: restek innovation !
35-550 amu
Solventdelay: 3.20 min.
Tune: DFTPP DrilledUniliner"'- see page11.
Ionization: EI
Website : E-mail : TelNo : 03 9762 2034 . . . in AUSTRALIA