Adsorptive removal of Hg2+ from environmental water samples using thioglycerol-intercalated magnetic layered double hydroxides

Herein, the removal of Hg2+ from environmental water samples was carried out using a novel nanoadsorbent based on magnetite nanoparticles coated by a thioglycerol-intercalated layered double hydroxide. The prepared material was characterized using scanning electron microscopy equipped with an energy dispersive X-ray analyzer and Fourier transform infrared spectrometry. The effective parameters of the removal procedure were identified and optimized through the one-variable-at-a-time method. Under the optimal conditions, the removal characteristics of the synthesized adsorbent including selectivity, distribution coefficient, and loading capacity were calculated in the presence of some interfering ions. The removal efficiency of 94.98 together with the distribution coefficient of 5.00 � 105 mL g-1 and loading capacity of 480.69 mg g-1 showed the considerable capability of this novel adsorbent in the selective removal of Hg2+ from aqueous samples. To evaluate the performance of the synthesized adsorbent in the removal of Hg2+ from environmental water samples, the removal of the desired analyte was carried out using four different real samples. The removal procedures were conducted at the analyte concentration levels of 10.0 and 50.0 mg L-1 for each aqueous sample. The obtained results showed that the removal efficiency was in the range of 91.99-94.97, which confirmed the high performance of the synthesized adsorbent in the removal of Hg2+ from real samples. Furthermore, the relative standard deviation of as low as 4.18-6.17 showed the acceptable repeatability of this method. © 2020 The Royal Society of Chemistry

Polydopamine-Functionalized Carbon Nanotubes for Pipette-Tip Micro-Solid Phase Extraction of Malathion and Parathion from Environmental Samples

In this study, a polydopamine-functionalized multi-walled carbon nanotube was utilized in an efficient pipette-tip micro-solid phase extraction followed by gas chromatography-mass spectrometry for determination of two organophosphorus pesticides called malathion and parathion. All the effective parameters were optimized using a one variable at-a-time protocol. Under the optimal conditions, broad calibration curves were obtained with the linearity in the range between 0.30�200 ng mL�1. Preconcentration factors as high as 42.7 and 47.3 for malathion and parathion, respectively, were obtained along with the relative standard deviations (RSD) lower than 6.37 . Real samples analysis was carried out using the optimized technique for quantitative analysis of the target analytes in environmental water samples. Relative recoveries in the range between 89.37�101.22 show the capability of the method in real sample analysis. © 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinhei

Microextraction on a screw for determination of trace amounts of hexanal and heptanal as lung cancer biomarkers

Solid phase microextraction on a screw was utilized for the extraction of hexanal and heptanal as lung cancer biomarkers from urine samples. Reduced graphene oxide (rGO) was coated on the surface of a stainless-steel set screw by electrophoretic deposition method. The screw was located inside a glass cover, and the created channel acted as the sample solution flow pass. A 5 mL glass syringe was connected to a syringe pump to direct the sample and the eluent through the channel. The extraction procedure was followed by gas chromatography/mass spectrometry (GC/MS) for separation and determination of the extracted aldehydes. The effective parameters on the extraction efficiencies of the analytes were identified and optimized. Under the optimal extraction conditions, the extraction time was as short as 10 min. The calibration curves indicated good linearity (R2 > 0.97) within the concentration range of 1.0�50 μg L�1. The obtained limits of detection (LODs) for hexanal and heptanal were down to 0.4 and 0.3 μg L�1, respectively. Considering the repeatability, simplicity, and eco-friendliness of this simple extraction method, it can be efficiently used for preconcentration of aldehydes in different samples. © 2020 Elsevier B.V

The electromagnetic interference of mobile phones on the function of a γ-camera

PURPOSE: The aim of the present study is to evaluate whether or not the electromagnetic field generated by mobile phones interferes with the function of a SPECT γ-camera during data acquisition. METHODS: We tested the effects of 7 models of mobile phones on 1 SPECT γ-camera. The mobile phones were tested when making a call, in ringing mode, and in standby mode. The γ-camera function was assessed during data acquisition from a planar source and a point source of Tc with activities of 10 mCi and 3 mCi, respectively. A significant visual decrease in count number was considered to be electromagnetic interference (EMI). RESULTS: The percentage of induced EMI with the γ-camera per mobile phone was in the range of 0% to 100%. The incidence of EMI was mainly observed in the first seconds of ringing and then mitigated in the following frames. CONCLUSIONS: Mobile phones are portable sources of electromagnetic radiation, and there is interference potential with the function of SPECT γ-cameras leading to adverse effects on the quality of the acquired images. © 2013 by Lippincott Williams and Wilkins