Simultaneous determination of chlorothalonil and its metabolite 4-hydroxychlorothalonil in greenhouse air: dissipation process of chlorothalonil.

An analytical method was developed and tested for the simultaneous determination of chlorothalonil and its main metabolite 4-hydroxychlorothalonil, in airborne samples. High performance liquid chromatography equipped with Ultra-violet detector was used to separate and quantify the analytes. Glass microfibre filters for the collection of the analytes' particles were tested.

Determination of dithiocarbamate fungicide propineb and its main metabolite propylenethiourea in airborne samples.

A simple, rapid and sensitive GC-MS method for the determination of dithiocarbamate fungicide propineb [polymeric zinc propylenebis (dithiocarbamate)] and an improved HPLC procedure for the simultaneous determination of its main metabolite, propylenethiourea, and ethylenethiourea, the main metabolite of all ethylenedithiocarbamates, in airborne samples are described. The method for the analysis of propineb involves the evolution of carbon disulfide (CS(2)), under acidic conditions in the presence of stannous chloride, extraction of the generated CS(2) into a layer of isooctane which is then analyzed for CS(2) content by GC-MS in SIM mode. Under the optimum conditions, the retention time of CS(2) was 1.

Determination of plasma, urine, and bovine serum albumin low-molecular-weight carbonyl levels by capillary gas chromatography with electron-capture and mass-selective detection.

Peroxidation of lipids produces low-molecular-weight carbonyl compounds, which are reactive with biological nucleophiles. The analysis of these compounds is often difficult. A multicomponent method for the determination of 11 of them in biological samples is reported.

Cyanuric acid trace analysis by extractive methylation via phase-transfer catalysis and capillary gas chromatography coupled with flame thermoionic and mass-selective detection. Process parameter studies and kinetics.

A GC method using phase-transfer catalysis for the simultaneous derivatization, extraction, and preconcentration of the highly polar cyanuric acid (CYA) was developed. The method was based on the extractive N-methylation of the analyte of concern in two- and three-phase systems, whereby the 1,3,5-trimethyl-1,3,5-triazine-2,4,6-(1H,3H,5H)trione was formed. Subsequent detection was performed using flame thermoionic specific detection (FTD) and mass spectrometry (MS) selective-ion monitoring (SIM) using electron impact.

Ion chromatographic method for the simultaneous determination of nitrite and nitrate by post-column indirect fluorescence detection.

This short paper highlights the suitability of ion chromatography with post-column indirect fluorescence detection to determine simultaneously nitrite and nitrate based on the quenching of tryptophan native fluorescence. The method uses an enhanced fluorescence mobile phase containing tryptophan and detects the suppression of fluorescence of the mobile phase due to the elution of the target ions. The phenomenon of fluorescence quenching of tryptophan is highly induced by the presence of phosphate ions.