consultancy contract - acid herbicides - hydrolysis of...

25

Upload: others

Post on 04-Sep-2019

11 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: Consultancy Contract - Acid Herbicides - Hydrolysis of Estersdwi.defra.gov.uk/research/completed-research/reports/dwi0761.pdf · Acid 1. 2. 3. Herbicides and Phenols - Hydrolysis
Page 2: Consultancy Contract - Acid Herbicides - Hydrolysis of Estersdwi.defra.gov.uk/research/completed-research/reports/dwi0761.pdf · Acid 1. 2. 3. Herbicides and Phenols - Hydrolysis

Acid

1.

2.

3.

Herbicides and Phenols - Hydrolysis of Esters

Introduction

Acid herbicides (alkoxy-alkanoic acids and related . ~- compounds) are commonly determined for residues in drinking and other waters. These compounds are however not always used in the form of the free acid or salt but in the form of an ester, or with phenolic herbicides as an ether. The analytical method normally used for the determination of these compounds does not involve a step to convert the esters to the free acids and hence these are not normally determined by the methylation and GC-MS method used.

The present work was aimed at developing a protocol for the analysis of the acid herbicides using alkaline hydrolysis. This procedure was evolved in a previous study on bromoxynil and ioxynil and was adapted by the Standing Committee of Analysts' draft method for these compounds. The method adopted for the analysis after 16hr hydrolysis with samples made alkaline to pH 12, involved re- acidification to pH 2, Cl8 cartridge extraction, elution with ethyl acetate, evaporation to incipient dryness, methylation with diazomethane and GC-MS using single ion monitoring. For the present work, external standards were used for quantification. All the tests were carried out in both distilled and tap water spiked (apart from the blanks) at a level of 0.1 ug/litre.

Source of Samples

2.1 Distilled water obtained from a standard laboratory still.

2.2 Tap water - Stevenage supply - calcium level approximately 100 mg/litre.

Standards

All the standards were obtained from QMx Ltd in the form of the free acids and as the appropriate ester or ether.

The acid herbicides used were: Benazolin Bromoxynil 2,4-D 2,4-DB Dichlorprop Fenoxaprop Fluazifop Fluroxypyr Ioxynil MCPA MCPB MCPP PCP 2,4,5-T Triclopyr

Page 3: Consultancy Contract - Acid Herbicides - Hydrolysis of Estersdwi.defra.gov.uk/research/completed-research/reports/dwi0761.pdf · Acid 1. 2. 3. Herbicides and Phenols - Hydrolysis
Page 4: Consultancy Contract - Acid Herbicides - Hydrolysis of Estersdwi.defra.gov.uk/research/completed-research/reports/dwi0761.pdf · Acid 1. 2. 3. Herbicides and Phenols - Hydrolysis
Page 5: Consultancy Contract - Acid Herbicides - Hydrolysis of Estersdwi.defra.gov.uk/research/completed-research/reports/dwi0761.pdf · Acid 1. 2. 3. Herbicides and Phenols - Hydrolysis
Page 6: Consultancy Contract - Acid Herbicides - Hydrolysis of Estersdwi.defra.gov.uk/research/completed-research/reports/dwi0761.pdf · Acid 1. 2. 3. Herbicides and Phenols - Hydrolysis
Page 7: Consultancy Contract - Acid Herbicides - Hydrolysis of Estersdwi.defra.gov.uk/research/completed-research/reports/dwi0761.pdf · Acid 1. 2. 3. Herbicides and Phenols - Hydrolysis
Page 8: Consultancy Contract - Acid Herbicides - Hydrolysis of Estersdwi.defra.gov.uk/research/completed-research/reports/dwi0761.pdf · Acid 1. 2. 3. Herbicides and Phenols - Hydrolysis
Page 9: Consultancy Contract - Acid Herbicides - Hydrolysis of Estersdwi.defra.gov.uk/research/completed-research/reports/dwi0761.pdf · Acid 1. 2. 3. Herbicides and Phenols - Hydrolysis
Page 10: Consultancy Contract - Acid Herbicides - Hydrolysis of Estersdwi.defra.gov.uk/research/completed-research/reports/dwi0761.pdf · Acid 1. 2. 3. Herbicides and Phenols - Hydrolysis
Page 11: Consultancy Contract - Acid Herbicides - Hydrolysis of Estersdwi.defra.gov.uk/research/completed-research/reports/dwi0761.pdf · Acid 1. 2. 3. Herbicides and Phenols - Hydrolysis
Page 12: Consultancy Contract - Acid Herbicides - Hydrolysis of Estersdwi.defra.gov.uk/research/completed-research/reports/dwi0761.pdf · Acid 1. 2. 3. Herbicides and Phenols - Hydrolysis
Page 13: Consultancy Contract - Acid Herbicides - Hydrolysis of Estersdwi.defra.gov.uk/research/completed-research/reports/dwi0761.pdf · Acid 1. 2. 3. Herbicides and Phenols - Hydrolysis
Page 14: Consultancy Contract - Acid Herbicides - Hydrolysis of Estersdwi.defra.gov.uk/research/completed-research/reports/dwi0761.pdf · Acid 1. 2. 3. Herbicides and Phenols - Hydrolysis
Page 15: Consultancy Contract - Acid Herbicides - Hydrolysis of Estersdwi.defra.gov.uk/research/completed-research/reports/dwi0761.pdf · Acid 1. 2. 3. Herbicides and Phenols - Hydrolysis
Page 16: Consultancy Contract - Acid Herbicides - Hydrolysis of Estersdwi.defra.gov.uk/research/completed-research/reports/dwi0761.pdf · Acid 1. 2. 3. Herbicides and Phenols - Hydrolysis
Page 17: Consultancy Contract - Acid Herbicides - Hydrolysis of Estersdwi.defra.gov.uk/research/completed-research/reports/dwi0761.pdf · Acid 1. 2. 3. Herbicides and Phenols - Hydrolysis
Page 18: Consultancy Contract - Acid Herbicides - Hydrolysis of Estersdwi.defra.gov.uk/research/completed-research/reports/dwi0761.pdf · Acid 1. 2. 3. Herbicides and Phenols - Hydrolysis
Page 19: Consultancy Contract - Acid Herbicides - Hydrolysis of Estersdwi.defra.gov.uk/research/completed-research/reports/dwi0761.pdf · Acid 1. 2. 3. Herbicides and Phenols - Hydrolysis
Page 20: Consultancy Contract - Acid Herbicides - Hydrolysis of Estersdwi.defra.gov.uk/research/completed-research/reports/dwi0761.pdf · Acid 1. 2. 3. Herbicides and Phenols - Hydrolysis
Page 21: Consultancy Contract - Acid Herbicides - Hydrolysis of Estersdwi.defra.gov.uk/research/completed-research/reports/dwi0761.pdf · Acid 1. 2. 3. Herbicides and Phenols - Hydrolysis
Page 22: Consultancy Contract - Acid Herbicides - Hydrolysis of Estersdwi.defra.gov.uk/research/completed-research/reports/dwi0761.pdf · Acid 1. 2. 3. Herbicides and Phenols - Hydrolysis
Page 23: Consultancy Contract - Acid Herbicides - Hydrolysis of Estersdwi.defra.gov.uk/research/completed-research/reports/dwi0761.pdf · Acid 1. 2. 3. Herbicides and Phenols - Hydrolysis
Page 24: Consultancy Contract - Acid Herbicides - Hydrolysis of Estersdwi.defra.gov.uk/research/completed-research/reports/dwi0761.pdf · Acid 1. 2. 3. Herbicides and Phenols - Hydrolysis
Page 25: Consultancy Contract - Acid Herbicides - Hydrolysis of Estersdwi.defra.gov.uk/research/completed-research/reports/dwi0761.pdf · Acid 1. 2. 3. Herbicides and Phenols - Hydrolysis