Lowering detection limits for 1,2,3-trichloropropane in water using solid phase extraction coupled to purge and trap sample introduction in an isotope dilution GC-MS method.
Purge and trap sample introduction (PTI) has been the premier sampling and preconcentration technique for gas chromatographic determination of volatile organic compounds (VOCs) in drinking water for almost 50 years. PTI affords sub parts-per-billion (ppb) detection limits for purgeable VOCs including fixed gases and higher boiling hydrocarbons and halocarbons. In this study the coupling of solid phase extraction (SPE) to PTI was investigated as a means to substantially increase enrichment and lower detection limits for the emerging contaminant, 1,2,3-trichloropropane (TCP). Water samples (500 mL) were dechlorinated, preserved with a biocide, and spiked with the isotope labeled internal standard, d5-TCP. The entire 500 mL sample was extracted with activated carbon or carbon molecular sieve SPE cartridges, and then eluted with dichloromethane -- excess solvent was removed in a nitrogen evaporator and diethylene glycol "keeper" remaining was dispersed in 5 mL of water for PTI GC-MS analysis. The experimental Method Detection Limit (MDL) for TCP was 0.11 ng/L (ppt) and accuracy was 95-103% in sub-ppt determinations. Groundwater samples including impaired California sources and treated water (n = 21) were analyzed with results ranging from below the method reporting limit (0.30 ng/L) to > 250 ng/L. Coupling of SPE with PTI may provide similar reductions in detection limits for other VOCs with appropriate physical-chemical properties.
Drinking Water and Radiation Laboratory Branch, Center for Environmental Health, California Department of Public Health, 850 Marina Bay Parkway, Richmond, CA, 94804, United States.
Wenta
W
Liao
Drinking Water and Radiation Laboratory Branch, Center for Environmental Health, California Department of Public Health, 850 Marina Bay Parkway, Richmond, CA, 94804, United States.
Miriam
M
Ghabour
Drinking Water and Radiation Laboratory Branch, Center for Environmental Health, California Department of Public Health, 850 Marina Bay Parkway, Richmond, CA, 94804, United States. Electronic address: william.draper@cdph.ca.gov.
William M
WM
Draper
Drinking Water and Radiation Laboratory Branch, Center for Environmental Health, California Department of Public Health, 850 Marina Bay Parkway, Richmond, CA, 94804, United States.
Esala
E
Chandrasena
D002138:Calibration; D002140:California; D002244:Carbon / Q000737:chemistry; D002849:Chromatography, Gas; D002853:Chromatography, Liquid; D004202:Disinfectants / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D060587:Groundwater; D054879:Halogenation; D006838:Hydrocarbons / Q000032:analysis; D006843:Hydrocarbons, Chlorinated / Q000032:analysis; D007554:Isotopes / Q000032:analysis; D057230:Limit of Detection; D011407:Propane / Q000031:analogs & derivatives* / Q000032:analysis; D015203:Reproducibility of Results; D052616:Solid Phase Extraction; D012997:Solvents; D055549:Volatile Organic Compounds / Q000032:analysis; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*
D004202:Disinfectants; D006838:Hydrocarbons; D006843:Hydrocarbons, Chlorinated; D007554:Isotopes; D012997:Solvents; D055549:Volatile Organic Compounds; D014874:Water Pollutants, Chemical; D014867:Water; C009536:1,2,3-trichloropropane; D002244:Carbon; D011407:Propane
1,2,3-trichloropropane; Isotope dilution GC-MS; Purge and trap; Solid phase extraction; Tandem sample preparation and introduction; Ultratrace water analysis; Volatile organic compounds