Simultaneous determination of 17 pesticide residues in rice by GC/MS using a direct sample introduction procedure and spiked calibration curves

A reliable, rapid and accurate method based on spiked calibration curves and direct sample introduction was developed for determination of 17 pesticide residues in rice by gas chromatography-mass spectrometry single quadrupole selected ion monitoring GC/MS-SQ-SIM. Sample preparation is based on extraction with acetonitrile without clean up. The use of spiked calibration curves for constructing the calibration curve substantially reduced adverse matrix-related effects. The average recovery of pesticides at 6 concentration levels was in range of 97.5-102.1%. The method was proved to be repeatable with RSDr in range of 0.7%-19.8%for all of the concentration levels. The limits of detection and limit of quantifications for all the pesticides were < 10 ng/g and < 25 ng/g, respectively. The developed method was applied for simultaneous determination of the selected pesticides in 23 rice samples collected from Tehran retail market in March 2009. Although many studies have been conducted regarding the determination of pesticides by using GC-MS, this is the first attempt in Iran using GC-MS-SIM technique that successfully can determine 17 pesticides with difference in physicochemical properties in rice

Performance evaluation of electrocoagulation process for diazinon removal from aqueous environments by using iron electrodes

The present study investigates the removal of pesticide by electrocoagulation process. A glass tank in 1.56 L volume with four iron plate electrodes was used to perform the experiments. The electrodes connected to a DC power supply [bipolar mode]. The tank was filled with synthetic wastewater were which contained diazinon pesticide in concentration of 10, 50 and 100 mg/L. The percent of diazinon removal was measured at pH= 3, 7 and 10 and in electric potential range of 20-40V by thin layer chromatography method. The results indicated that initial concentration of diazinon can affect efficiency removal and for higher concentrations of diazinon, higher electrical potential or more reaction time is needed. The results showed that for a given time, the removal efficiency increased significantly with increase of voltage. The highest electrical potential [40V] produced the quickest treatment with >99% diazinon reduction occurring after 60 min. The final pH for iron electrodes was always higher than initial pH. Finally it can be concluded that electrocoagulation process [using iron electrodes] is a reliable, efficient and cost-effective method for removal of diazinon from aqueous environments, especially designed for pH=3 and voltage40V

Monitoring of organochlorine pesticide residues in milk powder

Milk Powder is used in Egypt as infant food and also for adults. Contamination of milk powder with organochlorine pesticide residues was investigated in samples collected from the markets which belong to different producers. Hexachlorocyclohexane alpha and beta isomers and p, p/ DDE- residues were found to contaminate all milk powder samples with concentrations ranged between 0.36-0.81 ppb, 4.76-9.19 ppb and 0.84-6.11 ppb respectively when the milk powder was diluted with tap water and between 0.23-0.95 ppb, 4.76-11.91 ppb and 1.24-6.24ppb respectively when diluted with boiled water. Analysis of tap water and boiled water results indicated the presence of low concentrations of organochlorine pesticide residues. Some of which decreased by the thermal treatment i.e. alpha HCH from 0.013 to 0.003 ppb, dieldrin from 0.054 to 0.004 ppb and non significant p, p/ DDE from 0.100 to 0.089 ppb. While beta HCH showed opposite pattern as its residues increased from 0.153 to 0.439 ppb after boiling the water. Some of the milk powder studied are specified as babies and infant food. Daily intake of detected contaminants was calculated and referred to their Acceptable Daily Intake [ADI]

Base legal que sustenta los controles de foco de intoxicaciones agudas por plaguicidas y el registro y control nacional de plaguicidas de uso en salud pública y domestico / Legal base

Documento que presenta la propuesta de las Bases legales que sustente el uso y manejo de las sustancias tóxicas, las que han reflejado una alta incidencia de intoxicaciones agudas con efectos crónicos en cierto sector de la población nicaragüense. El establecimmiento de éstas, estan estrechamente vinculadas a la decisión de las autoridades de Salud de considerar el problema de los plaguicidas como un problema de salud pública, ha permitido desarrollar un Programa de plaguicidas que ha reforzado la red de vigilancia epidemiológica para prevenir y detectar oportunamente los casos y brotes de contaminación aguda por medio de plaguicidas