Publications by authors named "Sherif M Taha"

Prochloraz and tebuconazole are well-known fungicides for broad applications, including medical, industrial, and agricultural. They are frequently used simultaneously which increases the probability of their co-existing in various water sources. In this study, the analysis of PCZ or TBZ in water was performed by a direct analysis using the liquid chromatography-tandem mass spectrometry technique (LC-MS/MS).

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Accurate and highly sensitive analysis of folpet and captan was accomplished using liquid chromatography-triple quadrupole linear ion trap mass spectrometry (LC-QqQIT) with selective ion mode; mass filtering, collision, and trapping condition. Dimensional mass spectrometry (MS) parameters were optimized for the residue detection of folpet and captan in six food commodities (apples, tomatoes, sweet pepper, wheat flour, sesame seeds, and fennel seeds). The sample preparation method was based on the known QuEChERS protocol, except a mixture of acetonitrile/acetone was used for the sample extraction from the sesame seeds.

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In the current study, Pesticide residue extraction in beeswax was carried out using a mixture of acetonitrile-ethyl acetate (1:3, v/v). This mixture of solvents not only enables the melting of beeswax sample at a lower temperature than when using acetonitrile only but also introduces one phase solution. The sample extract was directly injected into both GC-MS/MS, of the commonly used split-less inlets, and into LC-MS/MS.

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This study describes the high sensitivity and the reduced ion suppression and matrix effect that can be achieved by supercritical fluid chromatography (SFC) in the analysis of dried spices as complex matrices. Samples selected for the evaluation were cayenne and black pepper, which are representative of complex dried spices. To carry out the evaluation of this technique, blank samples were fortified with a solution containing 162 pesticides at two concentration levels (50 and 200 μg kg).

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A simple and efficient multi residue method was developed, for the analysis of 160 pesticides by GC-MS/MS in herbal plants. The developed method employs pesticide residue extraction by EtAC/ n. hexane (6:4) with a cleanup step using florisil/ PSA mixture.

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