Determination of the Pesticide Chlorothalonil by HPLC and UV Detection for Occupational Exposure Assessment in Greenhouse Carnation Culture*

Abstract

An HPLC method was developed for application in the measurement of occupational exposure to the pesticide chlorothalonil. In addition, sampling methods were validated for the determination of exposure to chlorothalonil in the greenhouse culturing of carnations. Procedures for sampling of the inspirable fraction of aerosols, for the determination of hand contamination by hand rinse and the use of cotton gloves, and for the determination of dislodgable chlorothalonil residues on carnation leaves were validated. Normal phase HPLC with hexane-dioxane as the eluent and UV detection at either 254 or 325 nm appeared suitable for the determination of chlorothalonil in the described matrices. The limit of detection, after concentration on SepPak C18 cartridges was approximately 0.5 micrograms/L. Linear calibration curves were obtained in concentration ranges from 0.5 microgram/L to 100 mg/L. In general, no interferences were noticed in the analysis of the matrices. However, cotton gloves for determination of hand contamination had to be washed before use because they contained interfering material, and in the case of air sampling, glass fiber filters for air sampling appeared to degrade chlorothalonil very rapidly. Therefore, cellulose filters were used for collection of the inspirable fraction of aerosols containing chlorothalonil.

Permeation of chlorothalonil through nitrile gloves: Collection solvent effects in the closed-loop permeation method

“…Cotton gloves are inadequate protection against chlorothalonil because the fungicide was detected on pads under the gloves, and biological monitoring showed urinary chlorothalonil in a skin exposure situation [13]. This complemented previous greenhouse worker skin and glove exposure data [14][15][16]. There is a lack of quantitative permeation data of chlorothalonil through other glove types like the muchused disposable and chemically protective nitrile rubber materials, these being copolymers of acrylonitrile and butadiene of various thicknesses (disposable gloves are thinner) and extents of polymerization and layering [17].…”

Three Different Spectrophotometric Methods for Simultaneous Determination of Pyriproxyfen and Chlorothalonil Residues in Cucumber and Cabbage Samples

“…Chlorothalonil has moderate acute toxicity [12]. Many analytical methods are available to determine chlorothalonil residues in various matrices, but the wellknown methods are high-performance liquid chromatography-diode array detection [13,14] and high-performance liquid chromatography with UV detection [15][16][17][18]. Gas chromatography with electron capture detection [19][20][21] and by headspace solid-phase microextraction was coupled to gas chromatography with electron capture detection [22].…”

“…Ratio spectra (a) and first derivative ratio spectra (b) of pyriproxyfen(1,2,3,5,7,10,15,20,25, and 30 μg·mL − 1 ) when 1.5 μg·mL − 1 of chlorothalonil was used as the divisor in methanol (∆λ � 4 nm).…”

Determination of Azole Pesticides in Human Serum by Coupled Column Reversed-Phase Liquid Chromatography Using Ultraviolet Absorbance and Mass Spectrometric Detection

“…Direct measurement involves determination of the pesticide residues in the media through which the exposure occurs, such as measurement of pesticides adsorbed on clothing worn by workers. [1][2][3] These techniques provide a calculable measure of human exposure under actual conditions. However, this type of measurement is not always possible and, in addition, does not consider other multiple sources of entry of pesticides into the human body, such as ingestion, or through respiration and dermal absorption.…”