Trace Detection of Diphenhydramine by Adsorption on a Microelectrode at Flow Injection System by Fast Fourier Transform Continuous Cyclic Voltammetry

A continuous cyclic voltammetric study of diphenhydramine at gold micro electrode was carried out. Some investigations were also done to find the effects of various parameters on the sensitivity of the proposed method. The experiments were performed under the following conditions: pH = 2, the scan rate = 40 V/ s (v), accumulation potential = 500 mV (E), and accumulation time = 0.2 s (t). The drug in phosphate buffer (pH = 2.0) is adsorbed at optimized condition on the surface of electrode, giving rise to change in the current of well-defined oxidation peak of gold in the flow injection system. The proposed detection method is a very fast and appropriate technique for determination of the drug compound in a wide variety of chromatographic analysis methods. Signal-to-noise ratio has significantly increased by application of discrete Fast Fourier Transform (FFT) method, background subtraction and twodimensional integration of the electrode response over a selected potential range and time window. The linear concentration range was from 4.0 × 10–7 to 1.0 × 10–11 mol dm–3 (r = 0.9987) with a limit of detection and quantitation 5 × 10–12 and 4 × 10–11 mol dm–3, respectively. The method has the requisite accuracy, sensitivity, precision and selectivity to assay diphenhydramine in tablets

A number of modern industries and toxicants release: A review

Aim: The present study seeks to help the experts and specialists by investigating documents relevant to the harmful chemical compounds and toxic substances used in the production processes of a few novel industries so that, the information gap is identified by recognizing such toxicants and taking steps to fill such gap. Methods: By making the use of keywords related to the objective of the study (keywords such as toxicity, modern toxicity, modern industries (MIs), new toxins, modern/new chemical compounds), the indexed articles were searched from 2000 to 2022 in ProQuest, Science Direct, Pub Med, Scopus, Web of Science, and Google Scholar databases aiming at access to the toxic compounds in several MIs. In this study, out of 116 articles searched as full text and following the inclusion and exclusion criteria, 46 articles were wholly selected. Results: According to the results, the issues include the nanotechnology industry (silver-nanoparticles, gold-nanoparticles, titanium dioxide, zinc-oxide, cerium-dioxide, and iron-oxide nanoparticles), nuclear technology (cobalt [60 Co and 58 Co], uranium [235U], and plutonium [Pu4+]), semiconductor industries (arsenic compounds, phosphorus, dopants, acids, photoactive compounds, etc.), liquid crystal display industries (indium compounds and indium tin oxide), pharmaceutical and medical (cytotoxic and platinum-based drugs), modern dentistry (resins, silica-nanofillers, barium-glass, and beryllium compounds), as well as the MIs involved in silica, nickel, and dioxin nanoparticles, were documented and discussed. Conclusion: Developing MIs and equipping the traditional industries with new technologies have confronted humankind with different chemicals and toxins resulting from producing and using products that require attention, study, and research. It is hoped that the present review study will pave the way for extensive studies on occupational health and toxicology in MIs

Fabrication and Optimization of Molecularly Imprinted Nanofibers in Assessment of Occupational Exposure to 5-fluorouracil

Background and purpose: Cytotoxic drugs are a group of chemicals that raise concerns over the health of healthcare professionals. Therefore, accurate methods are needed to investigate the traces of these drugs. This study was done to fabricate and optimize molecularly imprinted membrane as a specific absorbent in assessment of occupational exposure to 5-fluorouracil. Materials and methods: 5-FU molecularly imprinted microspheres were produced by precipitation polymerization and encapsulated into nanofibers using electrospinning. Optimization of electrospinning parameters (MIP value, electrospinning voltage, the distance between needle tip to collector, and flow rate) was performed using response surface methodology (RSM) and Experimental design software. Totally, 22 trials were done on the basis of study design.  The diameter of the fiber was measured using SEM image analysis. The applicability of the synthesized membranes in absorbing 5-FU was evaluated. Results: In this study, MIP particles were successfully encapsulated into PET nanofibers. The optimization process showed that the molecularly imprinted nanofibers diameter of 276.38 nm could be obtained in 57%W MIP, 25 kV, 13 cm, and 0.55 ml/h. The efficacy of extracting 5-FU by synthesized membranes was 97.2±0.34. Conclusion: The experimental models presented in this study can be used in further experiments to create a uniform molecularly imprinted nanofibers for specific analyte absorption in occupational and environmental monitoring

Evaluation of direct reading photoionization detector performance under various operational parameters

The authors would like to thank Tehran University of Medical Sciences and Iran National Science Foundation (INSF) , for supporting this project. This study was supported by Tehran University of Medical Sciences under Ph.D. thesis scheme (Number: 9421138001) and the INSF. The funding body played no role in the design of the study, collection and analysis of data, interpreting results or writing the manuscript or decision to submit the manuscript for publication. The content of this publication is only the responsibility of the authors.Background: A hand-held portable direct-reading monitor, including photoionization detector (PID) is renowned for its good sensitivity, considerable dynamic range, and nondestructive vapor detection ability in comparison to the tardy response of the PID in gas chromatography (GC), which its application has been restricted. In this study, the performance of a PID system (MultiRAE Lite) was evaluated as a replacement of GC in the measurement of toluene in a dynamic adsorption system. Methods: The test was done at different relative humidity levels (30%, 50%, and 80%), temperatures (21, 30, 40°C), and toluene concentrations (20, 100, 200, and 400 ppm). Results: The PID achieved 48% of all measurements meeting the comparison criterion. The results showed that the performance of the PID could be altered by the variables. The best performance of the PID was at temperature of 21°C, the relative humidity of 50%, and concentration of 200 ppm with the percentage of readings achieving the criterion of comparison to 58%, 54%, and 52%, respectively. The averages of the PID readings (mean ± SD at 200 ppm= 207.9 ± 8.7) were higher than the reference method measurements averages (mean ± SD at 200 ppm= 203.5 ± 5.8). The regression analysis of the toluene results from the PID and the reference method results indicated that the measurements were significantly correlated (r2 = 0.93). Conclusion: According to the results, the device response is linear. Therefore, the findings are acceptable in adsorption studies. In this way, the measurement of the sample concentration should be performed using the same instrument before and after the reactor in order to calculate the adsorption efficiency.Tehran University of Medical SciencesIran National Science Foundation (INSF)Tehran University of Medical Sciences 9421138001Iran National Science Foundation (INSF

Optimization of Solid Phase Extraction for Trace Determination of Cobalt (II) Using Chromosorb 102 in Biological Monitoring

Cobalt is widely used in different industrial processes for production of various synthetic materials. For assessment of human exposure to toxic metal of Co (II), environmental and biological monitoring are essential processes, in which, preparation of samples is one of the most time-consuming and error-prone aspects prior to instrumental analysis. The aim of this study was to achieve optimum factors necessary for development of a sample preparation technique for cobalt (II), present in urine, hair, and nail samples followed by atomic absorption spectrometry. Solid phase extraction (SPE) using mini columns filled with Chromosorb 102 resin was optimized regarding sample pH, ligand concentration, loading flow rate, elution solvent, sample volume (up to 500 ml), elution volume, amount of resins, and sample matrix interferences. Cobalt ion was retained on sorbent and was eluted with 2 M HNO3 followed by determination by flame atomic absorption spectrometry. Obtained recoveries of cobalt ion were more than 92%. To evaluate occupational exposure to Co (II), successful applicability of the optimized method for human exposure was used by treatment real samples, including urine, hair, and nail. Suitable results were obtained for relative standard deviation (less than 10%). This optimized method can be considered successful in simplifying sample preparation for trace residue analysis of Co (II) in different matrices when an evaluation of occupational and environmental exposures is required

Occupational Exposure to Carbon Monoxide of Taxi Drivers in Tehran, Iran

Occupational exposure to carbon monoxide (CO) of taxi drivers has seldom been evaluated in Iran. Accordingly, in-vehicle CO levels were evaluated during 6 months inside the taxis between May 2009 and October 2010. The CO concentrations of 36 personal samples were collected using a direct reading instrument equipped with electrochemical sensor. The arithmetic mean of the personal monitoring CO levels was 19.84 ± 4.24 ppm per day, with a range of 13.29-33.46 ppm. The observed concentrations of CO fell well lower than occupational standards. Exposures to CO during traffic flow in the evening were considerably higher than those measured in the morning. The weekdays, months and atmospheric environment had a significant effect on exposure to CO (p< 0.0001). The average CO level was 19.84 ± 4.24 ppm, which was higher than the outdoor CO levels (3.21 ppm). In conclusion, the penetration of outdoor CO pollution and engine combustion/exhaust infiltration constituted the main sources of the taxis drivers' personal exposure to CO

Trace Detection of Diphenhydramine by Adsorption on a Microelectrode at Flow Injection System by Fast Fourier Transform Continuous Cyclic Voltammetry

A continuous cyclic voltammetric study of diphenhydramine at gold micro electrode was carried out. Some investigations were also done to find the effects of various parameters on the sensitivity of the proposed method. The experiments were performed under the following conditions: pH = 2, the scan rate = 40 V/ s (v), accumulation potential = 500 mV (E), and accumulation time = 0.2 s (t). The drug in phosphate buffer (pH = 2.0) is adsorbed at optimized condition on the surface of electrode, giving rise to change in the current of well-defined oxidation peak of gold in the flow injection system. The proposed detection method is a very fast and appropriate technique for determination of the drug compound in a wide variety of chromatographic analysis methods. Signal-to-noise ratio has significantly increased by application of discrete Fast Fourier Transform (FFT) method, background subtraction and twodimensional integration of the electrode response over a selected potential range and time window. The linear concentration range was from 4.0 × 10–7 to 1.0 × 10–11 mol dm–3 (r = 0.9987) with a limit of detection and quantitation 5 × 10–12 and 4 × 10–11 mol dm–3, respectively. The method has the requisite accuracy, sensitivity, precision and selectivity to assay diphenhydramine in tablets

Evaluation of Occupational Exposure of Glazers of a Ceramic Industry to Cobalt Blue Dye

Background: Cobalt is one of the most important constituent present in ceramic industries. Glazers are the relevant workers when they are producing blue colored ceramic, causing occupational exposure to such metal. Through this study, urinary cobalt was determined in glazers in a ceramic industry when they were producing blue-colored ceramic glazes.Methods: In this case-control study, spot urine samples were collected from 49 glazers at the start and end of work shifts (totally 98 samples) in 2011. Control group were well matched for age, height, and weight. A solid phase extraction system was used for separation and preconcentration of samples followed by analysis by inductively coupled plasma-atomic emission spectroscopy (ICP-AES).All participants filled out a self administered questionnaire comprises questions about duration of exposure, work shift, use of mask, skin dermatitis, kind of job, ventilation system, overtime work, age, weight, and height. The lung function tests were performed on each control and cobalt exposed subjects. Analysis of covariance (ANCOVA) was used to evaluate the obtained results.Results: Urinary levels of cobalt were significantly higher in the glazers compared to the control group. There were significant differences at urinary concentration of cobalt at the start and end of the work shift in glazers. Spirometric parameters were significantly lower in the glazers compared to the control group. Among the variables used in questionnaire the significant variables were dermatitis skin, mask, ventilation, and overtime work.Conclusion: This study verified existence of cobalt in the urine glazers, showing lower amount than the ACGIH standard