Synthesis and application of new silver and sulfur decorated S-doped reduced graphene oxide in ultra-trace analysis of pesticides by ion mobility spectrometry.

In this research study, a novel, facile, and affordable method is presented for the synthesis of a Ag/S/S-RGO nanocomposite. The resulting new nanocomposite was identified by FT-IR, XRD, FESEM, XPS, BET and EDX and employed as a rapid and effective adsorbent with acceptable absorption capacity for the analysis of various pesticides by dispersive solid-phase microextraction combined with ion mobility spectrometry. The main experimental parameters of the method were optimized such as the type of desorption solvent, pH of the sample solution, type of buffer, amount of the sorbent (Ag/S/S-RGO), sorption/desorption time, etc. Under the optimized conditions, linear dynamic ranges of 0.5-110.0, 1.0-110.0, and 0.8-90.0 ng mL-1 were achieved, with limits of detection of 0.25, 0.35, and 0.25 ng mL-1 for simazine, alachlor, and haloxyfop, respectively. The relative standard deviations (RSD%) were obtained as <5.0%. Eventually, the method was utilized for the simultaneous determination of simazine, alachlor, and haloxyfop in environmental and agricultural samples with recoveries between 95.0 and 104.6%.

Application of ZnS/S/S-RGO three-component nanocomposites in dispersive solid-phase microextraction coupled with ion mobility spectrometry for ultra-trace determination of multiclass pesticides.

A fast, effective, and sensitive dispersive solid-phase microextraction method coupled with ion mobility spectrometry for the simultaneous determination of bendiocarb, butachlor, and diazinon was developed using zinc sulfide/sulfur/sulfur-doped reduced graphene oxide (ZnS/S/S-RGO) nanocomposites. ZnS/S/S-RGO three-component nanocomposites were synthesized through a single-step solvothermal procedure, and their properties were characterized by FT-IR, XRD, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), and energy-dispersive x-ray spectroscopy (EDX). The influence of different parameters was optimized on the efficiency of the extraction including the type and the volume of desorption solvent, pH, type and the volume of buffer, the amount of absorbent, sorption and  desorption times. Under the optimal conditions, linear ranges were achieved 0.8-110, 1.0-110, and 0.5-100 ng mL-1 with detection limits of 0.32±0.01, 0.40±0.02, and 0.27±0.02 ng mL-1 for bendiocarb, butachlor, and diazinon, respectively. The method was employed for the ultra-trace determination of the three pesticides in water, rice, and soil samples with acceptable recovery values within the range 96.6±4.8-104.4±6.4%.

The effective factors on library anxiety of students in Isfahan University of Medical Sciences and Shiraz University of Medical Sciences.

INTRODUCTION: The efficient use of libraries can be an important factor in determining the educational quality of Universities. Therefore, investigation and identification of factors affecting library anxiety becomes increasingly necessary. The purpose of this research is to determine the factors effecting library anxiety of students in Isfahan University of Medical Sciences and Shiraz University of Medical Sciences. MATERIALS AND METHODS: This was an applied survey research using Bostick's Library Anxiety questionnaire as data gathering tool. The statistical population consisted of all students of Isfahan University of Medical Sciences and Shiraz University of Medical Sciences (15011 students) with the sample size of 375 using stratified random sampling. The validity of data gathering tool was confirmed by experts in the library and information science and its reliability was determined by Cronbach's alpha (r = 0.92). Descriptive statistics (frequency, percentage, mean and standard deviation) and inferential statistics (t-test and ANOVA) were used for data analysis using SPSS 18 software. RESULTS: Findings showed that the mean of library anxiety score was 2.68 and 2.66 for students of Isfahan University of Medical Sciences and Shiraz University of Medical Sciences respectively which is above average (2.5). Furthermore, age and gender had no meaningful effect on the library anxiety of students of Isfahan University of Medical Sciences, but gender had a meaningful effect on library anxiety of students of Shiraz University of Medical Sciences while age had no such effect. CONCLUSION: The results showed that the mean of factors effecting library anxiety in students of Isfahan University of Medical Sciences and students of Shiraz University of Medical Sciences is higher than average and therefore not satisfactory and only factors relating to feeling comfortable in the library is lower than average and somewhat satisfactory.