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Showing 5 results for Lc-Ms


Volume 6, Issue 2 (6-2020)
Abstract

Aim: Cereals and cereal-based products are prone to be infected by mycotoxin-producing fungi. The aim of this study was to investigate the level of contamination caused by 11 major mycotoxins in wheat samples collected from wheat silos in Tehran and Alborz provinces using UHPLC-MS/MS device.
Materials & Methods: Samples preparation was performed based on the extraction and purification procedures using acetonitrile/water/acetic acid solvents and Myco6in1 immunoaffinity columns, respectively. Selected mycotoxins were detected simultaneously using reversed phase ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) with electrospray ionization technique in positive-ion mode in a 15-minute run in the MRM program. Spiked samples calibration curve was used to overcome the matrix effects and to determine the residual mycotoxins.
Findings: Quantification and detection limits for AFB1 and OTA mycotoxins were 2 and 0.7 ppb; for DON, FB1, and FB2 were 100 and 33.3 ppb; for ZER were 50 and 16.6 ppb: for AFB2, AFG1, AFG2, and T-2 were 5 and 1.6 ppb; and for HT-2 were 20 and 6.6 ppb, respectively. Good precision and linearity was observed for mycotoxins. The average recovery rate of mycotoxins was in the range of 72-123 %, and the relative standard deviation (RSDr), indicating the method accuracy, was between 0.6-24.2 %. The validated method for analyzing the 30 wheat samples was used to evaluate the residual mycotoxins. OTA, T-2, and HT-2 mycotoxins were found in wheat samples. Only in one sample, the level of residual OTA exceeded the allowable limit set by the Iranian National Standards Organization.
Conclusion: The present study results highlighted the need for monitoring wheat and wheat-based products and the implementation of control and preventive measures in wheat fields, storage warehouses, and flour factories.

 

Volume 6, Issue 3 (8-2020)
Abstract

Background: The outbreak of novel coronavirus (2019-nCoV), which began in Wuhan, China, has rapidly spread in many countries and is currently considered a pandemic. The virus (SARS-CoV-2) causes severe acute respiratory syndrome and is related to SARS-CoV and MERS-CoV.
Methods: In this review, an introduction to SARS-CoV-2 was provided comprising the following items: general features; pathogenesis; the existing knowledge on immunological properties; transmission routs; diagnostic features, especially discussion about new approaches for treatment and prevention; and different diagnostic methods including nucleic acid based assays, serological testing, and MALDI TOF-MS and LC-MS technologies.
Findings and Conclusion: Introducing the different methods for SARS-CoV-2 detection may be useful to provide new insights into the development and improvement of detection primers, probes, methods/techniques, potential targets for drug designation, and therapeutic candidates against the virus.

Volume 7, Issue 3 (7-2018)
Abstract

Sorghum Sorghum bicolor L. releasing allelochemicals in the soil through their root exudation that functional their associated soil microorganisms and can help in building disease control strategy for increasing sustainability. The obtained results of sorghum rhizospheric exudates exhibited markedly effect on bacterial count in rhizosphere soil. The extract of root exudates profile was tested by two prepared concentrations; 500 ppm and 1000 ppm against the Bipolaris sorokiniana compared to untreated control. The reduction percentages were calculated after four and seven days of fungus growth, the results represented that the reduction over control were 17.53, 45.63% after four days, however after seven days the reductions over control were 17.28, 36.40%. For sorghum root parts, the reduction increase with increasing concentration ranged from 49.71 to 71.67%, the highest reduction was afforded by conc. 1600 ppm while the lowest reduction by 200 ppm. The analysis to identify sorghum allelochemicals was conducted by LC-MS/MS and FTIR afforded; proline, coumaric acid, cinnamic acid, hydroxycoumarin, benzoxazolone, ferulic acid and sorgoleone. While, sorghum root parts extract compounds were; coumaric acid, cinnamic acid, vanillic acid, luteolin3-Hydroxycoumarin, gallic acid, ferulic acid and sorgoleone. It could be used sorghum root exudates and root parts extract in disease bio-control due the effect of secreted biochemical molecules as step toward sustainable agriculture.
S. Soleimani , M. Yousefzadi , H. Rezadoost ,
Volume 9, Issue 4 (12-2018)
Abstract

Aims: Sea urchins have been extensively studied due to the commercial importance of their gonads in the global industry. Although after removal of the edible gonads, the remaining shell and spines are usually discarded, they are known to possess various polyhydroxylated naphthoquinone (PHNQ) pigments. The aim of the present research was quantitative and qualitative identification of PHNQ pigments from shell and spine of Echinometra Mathaei of the Persian Gulf.
Materials and Methods: In this experimental study, the Echinometra mathaei was used as the sea urchin test sample. Sea urchins were collected in 2013 from Zeytoon Park in Qeshm Island, Persian Gulf. Shell and spine pigments were extracted by hydrochloric acid from sea urchin. Then, the quantity of Naphthoquinone compounds was evaluated by spectrophotometric and their quality was evaluated by Liquid chromatography–mass spectrometry (LC-MS) and High-performance liquid chromatography (HPLC). The data were analysed by ANOVA and Duncan's new multiple range test at 5% probability level, using SPSS 19 software and the diagrams were drawn by Excel 2013 software.
Findings: The most pigments were Spinochrome A, C, B, and Echinochrome A, respectively. The presence of PHNQ pigments were confirmed in pigments Spinochrome B and C, Echinochrome A, and Spinochrome A, respectively.
Conclusion: The presence of each of the four pigments in shell and spine pigments is confirmed by quantitative and qualitative methods. The most pigments are Spinochrome A, C, B, and Echinochrome A, respectively.


Volume 19, Issue 126 (8-2022)
Abstract

In this research a validated and effective method was developed for simultaneous analysis of 60 pesticides in rice, using liquid chromatography-mass spectrometry (LC-MS/MS), then, the effects of washing and heating processes on residues of studied pesticides were investigated. Extraction was performed by the original QuEChERS method. The pesticides were analyzed simultaneously in a single run with a multiple reaction monitoring (MRM) method. The validation study was performed based on the SANTE 2019 guideline. The method was tested to assess for linearity, trueness, precision, specificity, limit of quantification (LOQ) and limit of detection (LOD). The results showed that the calibration curves for all studied compounds were linear with a coefficient of determination (R2) ranged between 0.984 - 1.000. The mean recoveries obtained for three fortification levels (25, 250, 1000 ng/g) were 76.4 - 110.2 % with satisfactory precision (RSD ranged between 2.8 – 16.7%.
After analysis of treated rice samples with investigated pesticides, the results indicated that both of washing and heating processes, in individual and combinational cases, significantly reduced the amounts of studied pesticides.


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