Sampling and Laboratory Analysis for Solvent Stabilizers - Environmental Investigation and Remediation - page 208

TABLE 4.5 (continued)
Operating Conditions for OCWD Purge and Trap, GC-MS/MS Method for
Low-Level Detection of 1,4-Dioxane

Sample Injection Conditions b

Settle 0.3 min

Prepurge 30 s

Sample pressurize 40-60 s

Sample transfer 75 s

Internal standard i ll 5 s

Internal standard transfer 50 s

Back l ush Off

Desorb time 4 min

Transfer line rinse Off

GC and MS Conditions c

Initial column temperature 35°C

Hold time 2 min

Final temperature 220°C

Temperature rate 3.1°C/min to 100°C; 100°C; to 220°C at 30°C/min

Hold time 1 min at 30°C/min

Helium linear velocity 1 mL/min

Total run time 27.97 min

Injector temperature 125°C

Detector Ion trap MS/MS

Transfer line 220°C

Mass range 40-100 m / z

Trap temperature 135°C

Background mass 40 m / z

EI (electron-impact ionization) current 80 μA

Scan time 0.36 s

Filament/multiply delay 14 min

Reagent ion ejection 20 V

Ion storage level 35.0 m / z

Ejection amplitude 20 V

High edge amplitude 15 V

Wave form Resonance

Source: FromYoo, L.J., Fitzsimmons, S., and Wehner, M., 2002, Improved purge-trap and GC/MS/MS tech-
niques for the trace-level determination of 1,4-dioxane in water. In: Proceedings, Water Quality Tech-
nology Conference . Seattle, WA: American Water Works Association, CD-ROM. With permission.

a

Purge and trap by Tekmar ALS 3100.

b

Sample injector by Tekmar AquaTek 50.

c

GC—Varian Model 3800; MS—Varian Saturn 2000 (column—DB-VRX fused-silica capillary column,
60 m × 0.32 mm ID with 1.8 μm i lm thickness).

4.4 LABORATORY METHODS FOR THE ANALYSIS OF 1,4-DIOXANE BY GC-MS
Laboratory methods using GC-MS form the subject of numerous topics and university courses.
This section presents only a brief synopsis of the key operative elements of these methods, in the
context of how they are modii ed to analyze for 1,4-dioxane.