Methods of Analysis by the U.S. Geological Survey Organic Geochemistry Research Group-- Determination of Triazine and Phenylurea Herbicides and Their Degradation Products in Water Using Solid-Phase Extraction and Liquid Chromatography/Mass Spectrometry

An analytical method for the determination of 7 triazine and phenylurea herbicides and 12 of their degradation products in natural water samples using solid-phase extraction and liquid chromatography/mass spectrometry is presented in this report. Special consideration was given during the development of the method to prevent the formation of degradation products during the analysis. Filtered water samples were analyzed using 0.5 gram graphitized carbon as the solid-phase extraction media followed by liquid chromatography/mass spectrometry. Three different water-sample matrices•ground-water, surface-water, and reagent-water samples•spiked at 0.2 and 2.0 micrograms per liter were analyzed.

Method detection limits ranged from 0.013 to 0.168 microgram per liter for the parent triazine herbicides and the triazine degradation products. Method detection limits ranged from 0.042 to 0.141 microgram per liter for the parent phenylurea herbicides and their degradation products. Mean recoveries for the triazine compounds in the ground- and surface-water samples generally ranged from 72.6 to 117.5 percent, but deethyl-cyanazine amide was recovered at 140.5 percent. Mean recoveries from the ground- and surface-water samples for the phenylurea compounds spiked at the 2.0-micrograms-per-liter level ranged from 82.1 to 114.4 percent. The mean recoveries for the phenylureas spiked at 0.2-microgram per liter were less consistent, ranging from 87.0 to 136.0 percent. Mean recoveries from reagent-water samples ranged from 87.0 to 109.5 percent for all compounds. The triazine compounds and their degradation products are reported in concentrations ranging from 0.05 to 2.0 micrograms per liter, with the exception of deethylcyanazine and deethylcyanazine amide which are reported at 0.20 to 2.0 micrograms per liter. The phenylurea compounds and their degradation products are reported in concentrations ranging from 0.20 to 2.0 micrograms per liter. The upper concentration limit was 2.0 micrograms per liter for all compounds without dilution.

CONTENTS

Abstract
Introduction
Determination of Triazine and Phenylurea Herbicides and Their Degradation Products in Water

Method of Analysis

Application
Summary of Method
Interferences
Apparatus and Instrumentation
Reagents and Consumable Materials
Sampling Methods
Standards
Safety Precautions

Evaluation of Instrument Performance

High-Performance Liquid Chromatograph and Diode Array Detector Performance
Mass Spectrometer Performance

Instrument Calibration
Alternate Calibration
Extraction Efficiency
Solid-Phase Extraction Procedure
Calculation of Results

Qualitative Identification
Quantitation
Alternate Quantitation

Reporting of Results
Method Performance

Corrections for Background Concentrations
Method Detection Limits
Mean Recovery

Discussion
Conclusions
References Cited
Appendix 1. AutoTrace program

Lee, E.A., Strahan, A.P., and Thurman, E.M., 2002, Methods of Analysis by the U.S. Geological Survey Organic Geochemistry Research Group•Determination of Triazine and Phenylurea Herbicides and Their Degradation Products in Water Using Solid-Phase Extraction and Liquid Chromatography/Mass Spectrometry: U.S. Geological Survey Open-File Report 02-436, 19 p.

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