AWWA WQTC58857

This study developed an electrospray ionization (ESI) liquid chromatography/mass spectrometry (LC/MS) method for the analysisof polar turfgrass pesticides that are commonly used in North America. The watersamples were first extracted by using a solid phase extraction (SPE) technique. The analysis was then carriedout with a Waters 2690 LC equipped with a ZMD detector. The separation wasperformed on a reverse phase C18 column. Acetonitrile/5 mM ammonium acetate inwater were used as the solvents for the gradient mobile phase profile. The flowrate wasset to 0.25 mL/min. The injection volume was 20 uL.This method was effectively used for the analysis of a number of turfgrass pesticides oflow volatility in finished drinking water, groundwater, and surface water. Thesecontaminants included bensulide, clopyralid, halofenozide, imidacloprid, mecoprop,neburon, oryzalin, paclobutrazol, triadimefon, triadimenol, etc. Bisphenol A-d16 wasused as the internal standard. 4-(4'-bromophenyl)phenol was used as the surrogate.The calibrations were in a range of 0.05-30 ug/L. The method detection limits (MDLs)were determined by measuring seven replicate laboratory fortified blanks spiked at themethod reporting level (MRL) at 0.5 ug/L or less. The MDLs were calculated as aproduct of the standard deviation of the replicate analyses and the student's t value witha 99% confidence level and a n-1 degree of freedom. The method accuracy (meanrecovery) and precision (relative standard deviation, RSD) were determined bymeasuring four replicate laboratory fortified blanks (LFBs) spiked at 5-10 ug/L. Includes 9 references, tables.

Product Details

Edition:

Vol. - No.

Published:

11/02/2003

Number of Pages:

3

File Size:

1 file , 290 KB