ABSTRACT
CONTENTS 19.1 Introduction ..................................................................................................................... 492 19.2 Fungicides ........................................................................................................................ 492
19.2.1 Protectant or Surface-Active Fungicides ...................................................... 493 19.2.2 Curative or Systemic Fungicides ................................................................... 493 19.2.3 Chemical Class.................................................................................................. 493
19.2.3.1 Carbamates and Derivates............................................................. 493 19.2.3.2 Substituted Benzenes...................................................................... 495 19.2.3.3 Dinitrophenols................................................................................. 495 19.2.3.4 Phthalimides .................................................................................... 496 19.2.3.5 Carboxamide (Oxathiins)............................................................... 496 19.2.3.6 Azoles and Derivatives .................................................................. 496
19.2.4 Antibiotics.......................................................................................................... 496 19.2.5 Fumigants .......................................................................................................... 497
19.3 Herbicides ........................................................................................................................ 497 19.3.1 Aliphatic Acids ................................................................................................. 499 19.3.2 Acetanilide......................................................................................................... 499 19.3.3 Benzoic or Arylaliphatic Acid Herbicides.................................................... 499 19.3.4 Benzonitrile Herbicides ................................................................................... 500 19.3.5 Bipyridyliums or Bipyridyls........................................................................... 500 19.3.6 Carbamate and Thiocarbamate Herbicides.................................................. 500 19.3.7 Triazines............................................................................................................. 500 19.3.8 Ureas................................................................................................................... 501
19.4 Regulations ...................................................................................................................... 501 19.5 Analytical Methods ........................................................................................................ 502
19.5.1 Sampling ............................................................................................................ 503 19.5.1.1 Well Water Sampling ..................................................................... 503 19.5.1.2 Potable Water Sampling ................................................................ 503 19.5.1.3 Surface Water Sampling ................................................................ 503
19.5.2 Sample Storage.................................................................................................. 503 19.5.3 Extraction........................................................................................................... 504
19.5.3.1 Liquid-Liquid Extraction............................................................... 504 19.5.3.2 Solid-Phase Extraction.................................................................... 505
19.5.4 Separation and Detection Methods ............................................................... 512 19.5.4.1 Gas Chromatography ..................................................................... 512
19.5.4.2 Liquid Chromatography................................................................ 515 19.5.4.3 Capillary Electrophoresis............................................................... 515 19.5.4.4 Mass Spectrometry.......................................................................... 517
19.6 Conclusions...................................................................................................................... 521 References ................................................................................................................................... 522
Pesticides are chemicals or biological substances used to kill or control pests. They fall into three major classes: insecticides, fungicides, and herbicides. Others classes are rodenticides, nematicides, molluscicides, and acaricides. These chemicals can be natural compounds or synthetic ones. Pesticides may also be divided into contact and systemic pesticides. Pesticides that were earlier produced were of the contact type. They do not appreciably penetrate plant tissue, so they are susceptible to the effects of the weather and moreover new plant growth is not protected. Vice versa, most of the recently developed pesticides are systemically active. They move through the plant vascular system and thus they not only can protect a plant from attack but also inhibit or cure established infections. Systemic pesticides are not affected by weathering and also confer immunity to all new plant growth. In 1993, 57% of all the pesticides used in the United States were herbicides, while 23% and 12% were insecticides and fungicides, respectively [1].
