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This article discusses an innovative automated microscale solid phase extraction (SPE) technology coupled with GC-MS for online analysis of water samples. The study includes details on the LVI-GC conditions, SPE Twin-PAL LVI-GC-MS extraction and collection plates, automated SPE conditions, and the SPE Twin-PAL LVI-GC-MS running sequence. The method's sensitivity, accuracy, and precision are also evaluated through online analysis of treated well water, untreated well water, and tap water samples.
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An Innovative Automated Microscale Solid Phase Extraction Technology Coupled with GC-MS for Online Analysis of Water Samples Pittcon 2000 March 14, 2000 Yongtao B. Li, Ed J. George, Earl M. Hansen, and Jerry J. Thoma and Werner Martin and Peter D. Smith (LEAP Technologies)
LVI-GC Conditions • Injection Vol.: 50 µL eluate • Injector Temp.: 80 ºC for 1 min, 80-280 ºC at 300ºC/min, 280 ºC for 34 min • Vent Valve: 0-0.6 min open, 0.6-3.5 min closed, 3.5- 37 min open • Vent Flow: 85 mL/min • Column Temp.: 45 ºC for 3 min, 45-160 ºC at 50 ºC/min, 160-260 ºC at 5 ºC/min, 260-330 ºC at 6 ºC/min, 330 ºC for 1 min • Helium: 26 cm/s at 100 ºC
Automated SPE Conditions • Cleaning: 500 µL 1:1 dichloromethane:ethyl acetate • Conditioning: 500 µL methanol & 500 µL reagent water • Extraction: 10 mL samples • Washing:1 mL reagent water • Drying: 5 min nitrogen gas • Elution: 160 µL 1:1dichloromethane:ethyl acetate • Mixing:~ 90 µL eluate + 10 µL internal standard • Injection:50 µL
Automated Multi-Step Elution • 160 µL 1:1 dichloromethane:ethyl acetate at 10 µL/s. • 70 µL solvent, then soak for 60 s; • 30 µL solvent, then soak for 30 s; • 30 µL solvent, then soak for 30 s; • 30 µL solvent, then soak for 30 s. • Flush with nitrogen gas at 15 psi for 5 s.
SPE Twin-PAL LVI-GC-MS Calibrations 1.6 Heptachlor 1.4 Bromacil Heptachlor Epoxide 1.2 gamma-Chlordane alpha-Chlordane 1 trans-Nonachlor Dieldrin 0.8 Endrin 0.6 0.4 0.2 0 0 2 4 6 8 10 Environmental Health Laboratories 0.05-10 ug/L, 50 uL 2 R = 0.999-1.000 Sample Area/Standard Area Concentration, ug/L