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See Semivolatiles Clearly with Rugged, Reliable Rxi-SVOCms Columns

Outstanding inertness keeps calibrations passing and samples running.
Excellent resolution of critical pairs for improved accuracy.
Consistent column-to-column performance.
Long column lifetime.

Our Rxi-SVOCms column was named Best New Separations Product of the Year in the SelectScience Scientists' Choice Awards

Designed specifically for semivolatiles analysis, Restek’s new Rxi-SVOCms columns ensure consistent performance that will keep calibrations passing longer, so you can run more samples before needing to recalibrate the instrument or replace the column. Our new polymer and deactivation chemistries produce highly inert columns with tightly controlled selectivity resulting in exceptional performance for a wide range of analytes (acidic, basic, and neutral).

Rxi-SVOCms columns are tuned specifically to improve peak shape for challenging SVOCs, such as pentachlorophenol, pyridine, and benzidine, as well as to ensure optimized resolution of difficult polycyclic aromatic hydrocarbons (PAH). As shown in Figure 1, the most problematic reactive analytes show highly symmetrical peak shapes and good responses. In addition, excellent resolution (≥85% valley) is obtained for benzo[b]fluoranthene and benzo[k]fluoranthene, which are isobaric PAHs that must be separated chromatographically, as well as for indeno[1,2,3-cd]pyrene and dibenz[a,h]anthracene.

For chemists in the environmental industry who are slowed down by variable column performance, frequent calibration failures, and poor column lifetimes, switching to rugged Rxi-SVOCms columns can ensure data requirements are met longer and downtime is minimized.

cgarm-img — **Figure 1:** Rxi-SVOCms columns provide outstanding chromatographic performance, reliably producing good peak shape and resolution even for problematic compounds. Split injection is recommended, when possible, because is minimizes the effect of inlet contamination on transfer of sample to the analytical column.

	Peaks	t_R (min)
1.	(IS) 1,4-Dioxane-d8	1.87
2.	N-Nitrosodimethylamine	2.00
3.	Pyridine	2.03
4.	(SS) 2-Fluorophenol	2.67
5.	(SS) Phenol-d6	3.29
6.	Phenol	3.30
7.	Aniline	3.36
8.	Bis(2-chloroethyl) ether	3.40
9.	2-Chlorophenol	3.46
10.	1,3-Dichlorobenzene	3.59
11.	(IS) 1,4-Dichlorobenzene-D4	3.63
12.	1,4-Dichlorobenzene	3.65
13.	Benzyl alcohol	3.72
14.	1,2-Dichlorobenzene	3.78
15.	2-Methylphenol	3.80
16.	Bis(2-Chloroisopropyl)ether	3.84
17.	4-Methylphenol	3.93
18.	3-Methylphenol	3.93
19.	N-Nitrosodi-N-propylamine	3.95
20.	Hexachloroethane	4.07
21.	(SS) Nitrobenzene-D5	4.10
22.	Nitrobenzene	4.11
23.	Isophorone	4.32
24.	2-Nitrophenol	4.40
25.	2,4-Dimethylphenol	4.42
26.	Benzoic acid	4.46
27.	Bis(2-chloroethoxy)methane	4.51
28.	2,4-Dichlorophenol	4.61
29.	1,2,4-Trichlorobenzene	4.70
30.	(IS) Naphthalene-D8	4.76
31.	Naphthalene	4.78

	Peaks	t_R (min)
32.	4-Chloroaniline	4.82
33.	Hexachlorobutadiene	4.89
34.	4-Chloro-3-methylphenol	5.26
35.	2-Methylnaphthalene	5.43
36.	1-Methylnaphthalene	5.53
37.	Hexachlorocyclopentadiene	5.59
38.	2,4,6-Trichlorophenol	5.70
39.	2,4,5-Trichlorophenol	5.73
40.	(SS) 2-Fluorobiphenyl	5.79
41.	2-Chloronaphthalene	5.91
42.	2-Nitroaniline	6.00
43.	1,4-Dinitrobenzene	6.13
44.	Dimethyl phthalate	6.18
45.	1,3-Dinitrobenzene	6.20
46.	2,6-Dinitrotoluene	6.24
47.	1,2-Dinitrobenzene	6.29
48.	Acenaphthylene	6.31
49.	3-Nitroaniline	6.40
50.	(IS) Acenaphthene-D10	6.45
51.	Acenaphthene	6.48
52.	2,4-Dinitrophenol	6.50
53.	4-Nitrophenol	6.55
54.	2,4-Dinitrotoluene	6.63
55.	Dibenzofuran	6.65
56.	2,3,5,6-Tetrachlorophenol	6.73
57.	2,3,4,6-Tetrachlorophenol	6.77
58.	Diethyl phthalate	6.88
59.	4-Chlorophenyl phenyl ether	6.99
60.	Fluorene	6.99
61.	4-Nitroaniline	7.00
62.	4,6-Dinitro-2-methylphenol	7.03

	Peaks	t_R (min)
63.	N-Nitrosodiphenylamine	7.10
64.	N,N-Diphenylhydrazine	7.15
65.	(SS) 2,4,6-Tribromophenol	7.23
66.	4-Bromophenyl phenyl ether	7.47
67.	Hexachlorobenzene	7.53
68.	Pentachlorophenol	7.72
69.	(IS) Phenanthrene-D10	7.92
70.	Phenanthrene	7.94
71.	Anthracene	7.99
72.	Carbazole	8.15
73.	di-n-Butyl phthalate	8.49
74.	Fluoranthene	9.12
75.	Benzidine	9.24
76.	(SS) Pyrene-D10	9.32
77.	Pyrene	9.34
78.	(SS) p-Terphenyl-d14	9.49
79.	3,3'-Dimethylbenzidine	9.98
80.	Butyl benzyl phthalate	10.00
81.	Bis(2-ethylhexyl) adipate	10.09
82.	3,3'-Dichlorobenzidine	10.62
83.	Benz[a]anthracene	10.66
84.	(IS) Chrysene-D12	10.67
85.	Chrysene	10.71
86.	Bis(2-ethylhexyl) phthalate	10.71
87.	Di-n-octyl phthalate	11.68
88.	Benzo[b]fluoranthene	12.30
89.	Benzo[k]fluoranthene	12.34
90.	Benzo[a]pyrene	12.89
91.	(IS) Perylene-D12	13.00
92.	Indeno[1,2,3-cd]pyrene	15.32
93.	Dibenz[a,h]anthracene	15.40
94.	Benzo[ghi]perylene	15.95

Column	Rxi-SVOCms, 30 m, 0.25 mm ID, 0.25 µm (cat.# 16623)
Standard/Sample	8270 MegaMix standard (cat.# 31850)
	8270 Benzidines mix (cat.# 31852)
	Benzoic acid (cat.# 31879)
	Revised SV internal standard mix (cat.# 31886)
	Revised B/N surrogate mix (cat.# 31888)
	Acid surrogate mix (cat.# 31063)
Diluent:	Dichloromethane
Conc.:	20 µg/mL
Injection
Inj. Vol.:	1 µL split (split ratio 10:1)
Liner:	Topaz 4.0 mm ID single taper inlet liner with wool (cat.# 23303)
Inj. Temp.:	250 °C
Split Vent Flow Rate:	12 mL/min
Oven
Oven Temp.:	60 °C (hold 0.5 min) to 285 °C at 25 °C/min to 305 °C at 3 °C/min to 330 °C at 20 °C/min (hold 5 min)
Carrier Gas	He, constant flow
Flow Rate:	1.2 mL/min

Stable Calibrations Increase Sample Throughput

Failed calibrations mean lost productivity as sample analysis must be put on hold for time-consuming maintenance and recalibration. The improved inertness of Rxi-SVOCms columns overcomes this, resulting in an average response factor %RSD from the initial calibration of six columns of just 6% over all compounds and columns (Table I). Extremely low and consistent response factors ensure that calibrations will last longer, allowing more samples to be run before recalibration is required. As shown in Figure 2, consistent peak shapes and retention times are seen even across different concentrations of pyridine and pentachlorophenol, which are problematic compounds that tend to tail and often fail calibration criteria on columns that are not highly inert.

Table I: Stable performance means fewer recalibrations and more time available for running samples, which improves lab productivity. Green indicates passing initial calibrations (n = 6 columns).

Compound	Calibration Range (µg/mL)	Average %RSD of Response Factors
N-Nitrosodimethylamine	1 - 120	4.70%
Pyridine	1 - 120	6.10%
(SS) 2-Fluorophenol	1 - 120	1.70%
(SS) Phenol-d6	1 - 120	2.10%
Phenol	1 - 120	3.20%
Aniline	1 - 120	3.10%
Bis(2-chloroethyl)ether	1 - 120	2.40%
2-chlorophenol	1 - 120	2.80%
1,3-dichlorobenzene	1 - 120	2.60%
1,4-Dichlorobenzene	1 - 120	2.10%
Benzyl alcohol	1 - 120	3.30%
1,2-Dichlorobenzene	1 - 120	2.70%
2-Methylphenol	1 - 120	3.30%
Bis(2-chloroisopropyl)ether	1 - 120	2.40%
4-Methylphenol/3-methylphenol	1 - 120	3.30%
N-nitroso-di-n-propylamine	1 - 120	3.80%
Hexachloroethane	1 - 120	3.00%
(SS) Nitrobenzene-D5	1 - 120	1.60%
Nitrobenzene	1 - 120	2.60%
Isophorone	1 - 120	3.40%
2-Nitrophenol	1 - 120	7.00%
2,4-Dimethylphenol	1 - 120	3.70%
Benzoic acid	2.5 - 120	25.00%
Bis(2-chloroethoxy)methane	1 - 120	3.60%
2,4-Dichlorophenol	1 - 120	4.10%
1,2,4-Trichlorobenzene	1 - 120	2.80%
Naphthalene	1 - 120	3.20%
4-Chloroaniline	1 - 120	3.90%
Hexachlorobutadiene	1 - 120	3.70%
4-Chloro-3-methylphenol	1 - 120	4.40%
2-Methylnaphthalene	1 - 120	3.40%
1-Methylnaphthalene	1 - 120	3.60%
Hexachlorocyclopentadiene	1 - 120	6.90%
2,4,6-Trichlorophenol	1 - 120	5.90%
2,4,5-Trichlorophenol	1 - 120	6.20%
(SS) 2-Fluorobiphenyl	1 - 120	1.10%
2-Chloronaphthalene	1 - 120	2.80%
2-Nitroaniline	1 - 120	7.80%
1,4-Dinitrobenzene	1 - 120	11.10%
Dimethyl phthalate	1 - 120	3.40%
1,3-Dinitrobenzene	1 - 120	10.80%
2,6-Dinitrotoluene	1 - 120	7.80%
Acenaphthylene	1 - 120	4.10%
1,2-Dinitrobenzene	1 - 120	8.10%
3-Nitroaniline	1 - 120	5.80%
Acenaphthene	1 - 120	3.30%
2,4-Dinitrophenol	2.5 - 120	17.30%
4-Nitrophenol	1 - 120	7.90%
Dibenzofuran	1 - 120	3.50%
2,4-Dinitrotoluene	1 - 120	11.60%
2,3,5,6-Tetrachlorophenol	1 - 120	10.40%
2,3,4,6-Tetrachlorophenol	1 - 120	7.30%
Diethyl phthalate	1 - 120	4.50%
4-Chlorophenyl phenyl ether	1 - 120	3.60%
Fluorene	1 - 120	4.40%
4-Nitroaniline	1 - 120	9.10%
4,6-Dinitro-2-methylphenol	2.5 - 120	15.10%
N-nitrosodiphenylamine	1 - 120	4.60%
Diphenylhydrazine	1 - 120	4.60%
(SS) 2,4,6-Tribromophenol	1 - 120	5.50%
4-Bromophenyl phenyl ether	1 - 120	5.50%
Hexachlorobenzene	1 - 120	4.30%
Pentachlorophenol	1 - 120	10.60%
Phenanthrene	1 - 120	3.70%
Anthracene	1 - 120	4.80%
Carbazole	1 - 120	5.30%
di-n-Butyl phthalate	1 - 120	7.90%
Fluoranthene	1 - 120	5.10%
Benzidine	1 - 120	9.30%
(SS) Pyrene-D10	1 - 120	1.50%
Pyrene	1 - 120	4.30%
(SS) p-Terphenyl-d14	1 - 120	1.80%
3,3'-Dimethylbenzidine	1 - 120	9.50%
Butyl benzyl phthalate	1 - 120	8.60%
Bis(2-ethylhexyl)adipate	1 - 120	10.50%
3,3'-Dichlorobenzidine	1 - 120	8.50%
Benz[a]anthracene	1 - 120	3.20%
Chrysene	1 - 120	3.70%
Bis(2-ethylhexyl)phthalate	1 - 120	10.40%
Di-n-octyl phthalate	1 - 120	13.20%
Benzo[b]fluoranthene	1 - 120	5.60%
Benzo[k]fluoranthene	1 - 120	4.90%
Benzo[a]pyrene	1 - 120	6.30%
Indeno[123-cd]pyrene	1 - 120	7.20%
Dibenz[a,h]anthracene	1 - 120	7.50%
Benzo[ghi]perylene	1 - 120	6.40%
	Average %RSD:	6.00%

Restore Performance Easily with Rugged, Long Life Rxi-SVOCms Columns

Accumulation of components from highly complex environmental samples is a routine challenge, but it doesn’t have to be a column killer. Improved column chemistry ensures that Rxi-SVOCms column performance is durable even under very aggressive conditions. In Figure 3, we subjected columns to repeated injections of a dirty sample, monitored calibration performance, and cut off contaminated sections after every 30 sample injections. Even after 300 injections, performance was easily restored with a quick column trim as evidenced by fewer than 10% of compounds failing the post-trim calibration check. Bringing back performance with simple routine maintenance means more samples can be analyzed with less downtime and fewer column replacements.

**Figure 3:** Column performance is completely restored by trimming following repeated exposure to a highly complex sample. Rugged Rxi-SVOCms columns come back to life so you can keep running samples instead of changing columns and recalibrating.

Consistent Performance Is Built into Every Column

From our proprietary polymer chemistry to the final QC test, every aspect of manufacturing Rxi-SVOCms columns is tightly controlled and stringently tested. The result is extremely consistent column-to-column performance, so you get the same chromatography from every column you install. Stable retention times, even for 2,4-dinitrophenol, which is an active and often problematic compound, and extremely low-bleed profiles characterize Rxi-SVOCms columns (Figure 4).

	Peaks
1.	4-Picoline
2.	2-Ethylhexanoic acid
3.	1,6-Hexanediol
4.	4-Chlorophenol
5.	n-Tridecane
6.	1-Methylnaphthalene

	Peaks
7.	1-Undecanol
8.	n-Tetradecane
9.	Dicyclohexylamine
10.	Acenaphthene-d10
11.	2,4-Dinitrophenol
12.	Pentachlorophenol
13.	Benzidine

Column	Rxi-SVOCms, 30 m, 0.25 mm ID, 0.25 µm (cat.# 16623)
Standard/Sample	Low-level activity test mix
Diluent:	Dichloromethane
Conc.:	200 µg/mL
Injection
Inj. Vol.:	1 µL split (split ratio 200:1)
Liner:	Topaz 4.0 mm ID Precision inlet liner with wool (cat.# 23305)
Inj. Temp.:	250 °C
Split Vent Flow Rate:	236 mL/min
Oven
Oven Temp.:	125 °C (hold 12.5 min) to 340 °C at 20 °C/min (hold 4 min)
Carrier Gas	He, constant flow
Linear Velocity:	32 cm/sec @ 125 °C
Dead Time:	1.5885 min @ 125 °C

Detector	FID @ 350 °C
Make-up Gas Flow Rate:	40 mL/min
Make-up Gas Type:	N₂
Hydrogen flow:	40 mL/min
Air flow:	400 mL/min
Data Rate:	50 Hz
Instrument	Agilent 7890B GC
Sample Preparation	Samples were aliquoted into amber 2 mL, 9 mm short-cap, screw-thread vials (cat.# 21143) containing glass Big Mouth inserts (cat.# 21782) and sealed with 2.0 mL, 9 mm short-cap, screw-vial closures (cat.# 23842).

Reliably Resolve Challenging Environmental PAH Compounds

Polycyclic aromatic hydrocarbons (PAH) are some of the most difficult compounds to separate in semivolatiles methods. Reporting accurate results at trace-levels requires a highly selective and efficient column that can reliably separate closely eluting compounds. Figure 5 demonstrates that the Rxi-SVOCms column provides optimized resolution of 23 priority pollutants, including benzo[b]fluoranthene and benzo[k]fluoranthene which must be separated chromatographically in order to be reported individually.

EVSS3820D-UNV

	Peaks	t_R (min)
1.	Naphthalene	6.27
2.	2-Methylnaphthalene	7.09
3.	1-Methylnaphthalene	7.20
4.	Biphenyl	7.65
5.	2,6-Dimethylnaphthalene	7.84
6.	Acenaphthylene	8.17
7.	Acenaphthene	8.38
8.	2,3,5-Trimethylnaphthalene	8.85
9.	Fluorene	9.01
10.	Dibenzothiophene	10.02
11.	Phenanthrene	10.18

	Peaks	t_R (min)
12.	Anthracene	10.24
13.	1-Methylphenanthrene	10.94
14.	Fluoranthene	11.64
15.	Pyrene	11.91
16.	Benz[a]anthracene	13.45
17.	Chrysene	13.50
18.	Benzo[b]fluoranthene	15.13
19.	Benzo[k]fluoranthene	15.18
20.	Benzo[a]pyrene	15.69
21.	Indeno[1,2,3-cd]pyrene	17.77
22.	Dibenz[a,h]anthracene	17.82
23.	Benzo[ghi]perylene	18.26