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Uddin R.,Southern Zone Agricultural Research Center | Khan M.F.,University of Karachi | Iqbal S.,Southern Zone Agricultural Research Center | Abbas M.,Southern Zone Agricultural Research Center
Bulletin of Environmental Contamination and Toxicology | Year: 2011

The undesirable effects of green revolution include residues of extensively used pesticides in various food commodities. Several studies showed that pesticides could cause health problems. Keeping in view the problem of pesticide residues in various food commodities, the present study was conducted on domestic stored wheat as well as on imported wheat for the qualitative and quantitative analysis of organochlorine, organophosphorus and pyrethroids. Among the imported wheat, 22.5% samples were found contaminated by organophosphorus (chlorpyrifos 0.073-0.230 μg/g, malathion 0.0419-0.1003 μg/g) and pyrethroids (cypermethrin 0.1404-0.2005 μg/g, permethrin 0.0140-0.0480 μg/g) while in domestic wheat 6.7% samples were found contaminated by pyrethroids (deltamethrin 0.0650-1.2903 μg/g) only. Method used for extraction and analysis of insecticides was validated both by recovery studies and inter laboratory comparison proficiency test. The method recovery results show that the average recovery of the fortified wheat samples was in the range of 73.77%-100.17% with the RSD in the range of 2.21-9.27 whereas, the Z-scores of the inter laboratory comparison proficiency test's result was less than 2. © Springer Science+Business Media, LLC 2011. Source


Uddin R.,Southern Zone Agricultural Research Center | Iqbal S.,Southern Zone Agricultural Research Center | Khan M.F.,University of Karachi | Parveen Z.,Southern Zone Agricultural Research Center | And 2 more authors.
Bulletin of Environmental Contamination and Toxicology | Year: 2011

A simple, easy, cheap and efficient analytical method for determination of multiple pesticide residues including organochlorine, organophosphorus, synthetic pyrethroids and herbicides in rice grain by capillary gas chromatography is developed. The quantification of residues was done by capillary gas chromatography with a μ-ECD detector and a HP-5MS capillary column. Known amounts of a mixture of pesticides were added to grain prior to extraction, cleanup and GC-determination. Recoveries were checked at two fortification levels; 0.1 and 0.5 μg/g. Qualitative and quantitative analysis were carried out based on the retention time and peak area basis. The results show that the average recovery of the analytical method for the fortified rice samples was in the range of 74%-111% and %RSD in the range of 2.41-12.42. The analytical method was used to analyze commercial rice grain samples. © 2010 Springer Science+Business Media, LLC. Source


Iqbal S.,Southern Zone Agricultural Research Center | Uddin R.,Southern Zone Agricultural Research Center | Saied S.,University of Karachi | Ahmed M.,Southern Zone Agricultural Research Center | And 2 more authors.
Bulletin of Environmental Contamination and Toxicology | Year: 2012

This study presents an improved method for quantitative analysis of imidacloprid residues in wheat grain using high performance liquid chromatography. The study used chromatographic response (in terms of peak height) as a quantitative tool for determination instead of peak area. The peak height of imidacloprid showed a very good linear correlation (R2 = 0.999) when compared with absolute values at six different concentrations. The limit of detection was found to be 0.01 lg/mL. The recovery of imidacloprid residues in spiked wheat grain at three levels (0.03, 0.05, and 0.1 lg/g) was in the range of 79%-88% with %RSD 5.72 at 0.05 lg/g (w/w) and between 87% and 93% with %RSD 3.55 at 0.1 lg/g (w/w). At 0.03 lg/g (w/w) level, recovery was not within the recommended range of 70%-110%. Therefore, the lowest limit of quantification for this method was found to be 0.05 lg/g. © Springer Science+Business Media, LLC 2012. Source

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