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

[Comparison of RD, L20B and Hep2 cell lines sensitivity to the standard poliovirus and oral polio vaccine virus]

As we are approaching the global eradication of wild poliovirus, laboratory surveillance of poliovirus by the gold standard cell culture method becomes increasingly important. As there is a lot of concern about accurate and sensitive detection of imported wild and Vaccine Derived Polioviruses [VDPVs] in Polio-Free countries, in this study we assessed and compared the sensitivity of the cell lines used in polio laboratory simultaneously to standard poliovirus and Oral Polio Vaccine [OPV] polioviruses, to ensure the accurate detection of circulating and imported polioviruses in the society. Cell sensitivity test was performed according to the World Health Organization [WHO], Polio Laboratory Manual for RD, L20B and Hep2 cell lines using 3 serotypes of standard monovalent and OPV polioviruses. The test was repeated every four passages for all cell lines. The sensitivity of L20B and Hep2 cell lines for standard poliovirus type 1 and 2 is more than sensitivity for the same types of OPV virus but for poliovirus type 3 it is vice versa. Also RD cell line is more sensitive to all 3 types of OPV virus. In addition, the test showed that increasing the passage number will decrease the sensitivity of all cell lines. Using RD and L20B cell lines simultaneously [with low passage number] will assure us of sensitivity and accuracy of the cell lines for detection of circulating and imported polioviruses

Extraction and purification of Hesperidin and Naringin from Citrus aurantium var. Amara L. Peel

Citrus aurantium var. amara L. [Rutaceae] is a plant whose fruit, flower and essential oil are used very extensively as well as its vitamins. Because of the importance of vitamin P and considerable amount of flavonoids in the peel of this plant, the ripe and unripe peels of the plant were the subject of this investigation. At first, the extraction of flavonoids [hesperidin and naringin] was carried out by suitable solvents. Then, preparative chromatography procedure was applied for the purification of the two flavonoids. Structures were elucidated by spectroscopic and chemical means. This method of isolation yielded hesperidin 9.8% from ripe and 12% from unripe peels and naringin 0.1% from ripe and unripe peels

Anti-inflammatory and analgesic activity of methanolic extracts of aerial parts of Stachys Schtschegleevii sosn. and stachys balansae boiss. and kotschy ex boiss in rats

Extracts of the flowering aerial parts of Stachys schtschegleevii Sosn. and S. balansae Boiss. and Kotschy ex Boiss have been used in Iranian folk medicine as remedy for rheumatic and other inflammatory disorders and anti-inflammatory and analgesic effects of some species of Stachys e.g. Stachys inflata have been reported. In this study, the anti-inflammatory and antinociceptive properties of total methanolic extracts of the flowering aerial parts of two Stachys species in rat were investigated by carrageenan-induced paw edema and formalin test. Intraperitoneal injection of the extracts, 60 min before induction of inflammation, resulted in inhibition of carrageenan-induced rat paw edema in dose dependant manner [doses 50, 100 and 200 mg/kg]. In the formalin test, the extract [50, 100 and 200 mg/kg] had low effect in the first phase [0-5 min] of the formalin-induced pain, but all three doses showed analgesic and anti nociception effects significantly. In conclusion the methanolic extracts of Stachys schtschegleevii and Stachys balansae have analgesic and anti-inflammatory effects in formalin test and carrageenan-induced paw edema

Two new valepotriates from the roots of valeriana sisymbriifolia

A dicholoromethane extract of the roots of Valeriana sisymbriifolia Vahl. afforded a new valepotriate. I- alpha -aceisovaltrate and a new valepotriatehydrine, acetoxydesiovaleroxy-1- alpha -acetoxy-isovaleroxy isovaltratehydrine together with a known compound, valtrate. Structural assignments of the compounds were based on spectroscopic methods [UV, IR, MS, 1H-NMR and 13C-NMR]