MULTI-RESIDUE ANALYSIS OF IMAZAPYR, PICLORAM AND TRICLOPYR IN DRINKING WATER
Report No FR0475

K MOORE

MARCH 1994

SUMMARY

I BENEFITS

A sensitive and accurate analytical method for imazapyr, picloram and triclopyr using readily available equipment will allow their determination in drinking water. These pesticides, used as non-agricultural herbicides, are important but were previously difficult to analyse. The improved system for identifying priority pesticides that need methods of analysis would help focus resources.

II OBJECTIVES

The objectives of the work were to:

• Update the list of priority pesticides for analytical method development published previously (FR 0312).

• Select the most important priority pesticides for analytical method development.

• Improve the methodology for identifying priority pesticides for analytical method development.

• Develop and performance test an analytical method for the selected pesticides.

III REASONS

The Water Supply (Water Quality) Regulations 1989 impose a duty on water undertakers to monitor regularly for pesticides in water supplies. Sufficiently sensitive and accurate analytical methods are thus needed to monitor for all the pesticides that may be present in water supplies. In a previous report (FR 0312), those pesticides which may leach into water sources for which there are no satisfactory analytical methods were identified. Imazapyr, picloram and triclopyr were three of the pesticides on this priority list for analytical method development. It was thought to be particularly important to develop an analytical method for imazapyr and triclopyr because they are reported to be used as replacements for the non-agricultural uses of atrazine.

IV CONCLUSIONS

Imazapyr, picloram and triclopyr were selected for analytical method development. A multiresidue analytical method based on solid-phase extraction, methylation and gas chromatography with nitrogen/phosphorus detector has been developed. The analytical method has been performance tested and found to be capable of monitoring compliance with the Water Supply Regulations. The method could be extended to other related pesticides. An updated list of priority pesticides for method development was produced. In addition the method for selecting pesticides that require method development was improved.

V RECOMMENDATIONS

The analytical method described in this report should be used to determine concentrations of imazapyr, picloram and triclopyr in water supplies.

Analytical methods should be developed and tested for some of the other pesticides on the priority list of pesticides for analytical method development.

VI RESUME OF CONTENTS

The priority list of pesticides for analytical method development was updated using recently acquired information. Pesticides for analytical method development were selected from this list. An improved methodology for identifying priority pesticides for analytical method development was developed for future use by water companies or regulatory authorities. An analytical method for the selected pesticides (imazapyr, picloram and triclopyr) was developed and performance tested.

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