Ultrasound assisted emulsification microextraction for selective determination of trace amount of mercury(II)

An environmental friendly sample pre-treatment method, ultrasound assisted emulsification microextraction, followed by furnace atomic absorption spectrometry is reported for the selective determination of mercury(II). Parameters that affect the extraction efficiency, such as the kind and volume of the extraction solvent, volume of chelating agent, sample pH, extraction time, temperature and addition of salt, are optimized. Under the optimum conditions for extraction recovery, 80 µL of tetrachloroethylene as extraction solvent and 1000 µL of [4-benzylidenamino- 3,4 dihydro-6-methyl 3-thioxo-1,2,4-triazin-5(2H)-one] as complexing agent give the best results. Under the optimum conditions, the calibration curve is linear in the range of 100-800 µg L-1, relative standard deviation is 2.8% for five analysis of sample solution containing 0.3 mg L−1 Hg(II) with the limit of detection of 0.043 mg L-1. The method has been applied successfully for assessing matrix effect by analysis of non- piked and spiked real samples. The results demonstrate a successful robustness of the method for quantitative and selective determination of trace amount of mercury(II) in water and wastewater samples with relative recovery of 96-103%

ZnS and ZnS/ZnO assembly for photocatalytic removal of Reactive Red 66

The current work investigated the effect of ZnS and ZnS/ZnO assembly on the photocatalytic removal of Reactive Red 66 from an aqueous solution. The photocatalytic activities were carried out using both UV irradiation and visible light, and the effects of various operating parameters, such as pH, catalyst loading, dye concentration, and contact time, were studied. The results showed that the ZnS/ZnO heterostructure exhibited a higher dye removal percentage than ZnS alone and assisted in the photodegradation of Reactive Red 66. Maximum adsorption was found at pH 2 and 5, indicating that the dye removal was strongly pH-dependent. The highest dye removal efficiency under UV light was 77.7 and 91.7% using ZnS and ZnS/ZnO, respectively. Furthermore, the degradation percentage of Reactive Red 66 by ZnS and ZnS/ZnO decreased to 43.3 and 75.2% under visible light. The enhanced photocatalytic activity of the ZnS/ZnO heterostructure is attributed to its high absorption of light, efficient separation of electron-hole pairs, and quick surface reaction in the heterostructure

Ultrasound assisted emulsification microextraction for selective determination of trace amount of mercury(II)

423-428<span style="font-size:11.0pt;font-family: " times="" new="" roman";mso-fareast-font-family:"times="" roman";mso-bidi-font-family:="" mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:="" hi"="" lang="EN-GB">An environmental friendly sample pre-treatment method, ultrasound assisted emulsification microextraction, followed by furnace atomic absorption spectrometry is reported for the selective determination of mercury(II). Parameters that affect the extraction efficiency, such as the kind and volume of the extraction solvent, volume of chelating agent, sample pH, extraction time, temperature and addition of salt, are optimized. Under the optimum conditions for extraction recovery, 80 µL of tetrachloroethylene as extraction solvent and 1000 µL of [4-benzylidenamino- 3,4 dihydro-6-methyl 3-thioxo-1,2,4-triazin-5(2H)-one] as complexing agent give the best results. Under the optimum conditions, the calibration curve is linear in the range of 100-800 µg L-1, relative standard deviation is 2.8% for five analysis of sample solution containing 0.3 mg L−1 Hg(II) with the limit of detection of 0.043 mg L-1. <span style="font-size: 11.0pt;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-bidi-font-family:mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;="" mso-bidi-language:hi"="" lang="EN-GB">The method has been applied successfully for assessing matrix effect by analysis of non-spiked and spiked real samples. The results demonstrate a successful robustness of the method for quantitative and selective determination of trace amount of mercury(II) in water and wastewater samples with relative recovery of 96-103%.</span

Environmental Psychology Effects on Mental Health Job Satisfaction and Personal Well Being of Nurses

Objective: Environmental psychology as a science could be useful in understanding the dissociation between the man and the environment. The aim of this study was to compare mental health, job satisfaction and well-being of nurses who work in hospital environments with different designs. Material: This was a quasi-experimental study, in which 250 nurses filled out the mental health, well-being and job satisfaction questionnaires. They were categorized into 3 groups randomly. Group1 included 63 nurses who worked in an environment without any natural elements; group 2 included 100 nurses who worked in an environment with natural elements and group 3 included 87 nurses who worked in an environment without any psychological and ergonomic design. The last group was only stimulated by demonstrating visual stimulus. Data were analyzed using the ANOVA and Tukey’s pursuit statistical method. Results: The nurses who were working in an environment without any natural elements reported significantly lower scores on mental health, well-being and job satisfaction compared to those who were working in other groups, with the exception of social functioning .Moreover, depression and anxiety were more common in nurses who were working in environments without any natural elements compared to those in the other groups (p<0.05). Conclusions: We can increase job satisfaction, and mental health and well-being of the nurses through the use of natural design and environmental psychology indexes in hospital buildings

Diaminonaphthalene functionalized LUS-1 as a fluorescence probe for simultaneous detection of Hg2+ and Fe3+ in Vetiver grass and Spinach

Abstract One of the important problems in the environment is heavy metal pollution, and fluorescence is one of the best methods for their detection due to its sensitivity, selectivity, and relatively rapid and easy operation. In this study, 1,8-diaminonaphthalene functionalized super-stable mesoporous silica (DAN-LUS-1) was synthesized and used as a fluorescence probe to identify Hg2+ and Fe3+ in food samples. The TGA and FT-IR spectra illustrated that 1,8-diaminonaphthalene was grafted into LUS-1. XRD patterns verified that the LUS-1 and functionalized mesoporous silica have a hexagonal symmetrical array of nano-channels. SEM images showed that the rod-like morphology of LUS-1 was preserved in DAN-LUS-1. Also, surface area and pore diameter decreased from 824 m2 g⁻1 and 3.61 nm for the pure LUS-1 to 748 m2 g⁻1 and 3.43 nm for the DAN-LUS-1, as determined by N₂ adsorption–desorption isotherms. This reduction demonstrated that 1,8-diaminonaphthalene immobilized into the pore of LUS-1. The DAN-LUS-1 fluorescence properties as a chemical sensor were studied with a 340/407 nm excitation/emission wavelength that was quenched by Hg2+ and Fe3+ ions. Hg2+ and Fe3+ were quantified using the fluorescence response in the working range 8.25–13.79 × 10–6 and 3.84–10.71 × 10–6 mol/L, with detection limits of 8.5 × 10–8 M and 1.3 × 10–7 M, respectively. Hg2+ and Fe3+ were measured in vetiver grass and spinach. Since the Fe3+ quenching can move in the opposite direction with sodium hexametaphosphate (SHMP) as a hiding compound for Fe3+, consequently, the circuit logic system was established with Fe3+, Hg2+, and SHMP as inputs and the fluorescent quench as the output

To Construction and Standardization of the Waiting Anxiety Questionnaire (WAQ) in Iran.

Objective: This study aimed to develop and validate a questionnaire to measure waiting anxiety . Methods: This was a cross-sectional study. Extensive review of literature and expert opinions were used to develop and validate the waiting anxiety questionnaire. A sample of 321 participants was recruited through random cluster sampling (n= 190 Iranian men and n= 131 women). The participants filled out WAQ, the Speilberger‘s State-Trait Anxiety Inventory (STAI), Burtner Rating scale (BRS) and Eysenk Personality questionnaire (EPQ) for adults . Results: Internal consistency of WAQ was revealed, meaning that all the 20 items were highly correlated with the total score. The Cronbach alpha equaled 0.83 for the Waiting Anxiety Questionnaire . The Pearson correlation coefficient of the questionnaire with the STAI, BRS and extraversion and neuroticism subscales of EPQ was 0.65, 0.78, - 0.47 and 0.43, respectively, which confirmed its convergent and divergent validity. Factors analysis extracting four cognitive, behavior l, sentimental and physiological factors could explain 67% of the total variance with an Eigen value of greater than 1. Conclusion: Our findings suggest that WAQ possesses appropriate validity and reliability to measure the individuals’ anxiety during the waiting time

Fast chromium determination in pharmaceutical tablets by using electrochemical sensors: Preparation and comparison

In the present paper, three electrodes were prepared with the aim of detecting chromium (III) in pharmaceutical tablets and comparing their capabilities and efficiency. At first, N-(pyridine-2-ylcarbamothioyl) benzamide (NP2YCTB) was synthesized and characterized by 1H NMR, FTIR, and 13C NMR spectroscopy methods. Then, it is used as a sensing material to prepare three types of chromium potentiometry sensors including solid-state electrodes (SSE), coated wire electrodes (CWE) as asymmetric electrodes, and liquid membrane electrodes (LME) as symmetric electrodes. The responses of all electrodes were Nernstian. Field-emission scanning electron microscopy was utilized to investigate the liquid membrane morphology. The presence of chromium (III) in the membrane was proved using Energy-dispersive X-ray spectroscopy and the coordination of NP2YCTB heteroatoms with chromium (III) was confirmed by Fourier transform infrared spectroscopy. The limit of detection for SSE (3 × 10−9 mol/L) was enhanced compared with LME (7 × 10−6 mol/L) and CWE (3 × 10−7 mol/L). The response time of electrodes was very short so it was about 5–6 s for LME and CWE and 5–8 s for SSE. The sensors were used for the potentiometric determination of chromium (III) in pharmaceutical tablets and in the potentiometric titration of it with EDTA