Ionic liquid-based dispersive liquid–liquid microextraction for the determination of formaldehyde in wastewaters and detergents

Spectrophotometry in combination with ionic liquid-based dispersive liquid–liquid microextraction (DLLME) was applied for the extraction and determination of formaldehyde in real samples. The method is based on the reaction of formaldehyde with methyl acetoacetate in the presence of ammonia. The variation in the absorbance of the reaction product was measured at 375?nm. An appropriate mixture of ethanol (disperser solvent) and ionic liquid, 1-hexyl-3-methylimidazoliumhexafluoro-phosphate [C₆MIM][PF₆] (extraction solvent) was rapidly injected into a water sample containing formaldehyde. After extraction, sedimented phase was analyzed by spectrophotometry. Under the optimum conditions, the calibration graph was linear in the range of 0.1–20?ng?mL^?1 with the detection limit of 0.02?ng?mL^?1 and limit of quantification of 0.08?ng?mL^?1 for formaldehyde. The relative standard deviation (RSD%, n?=?5) for the extraction and determination of 0.8?ng?mL^?1 of formaldehyde in the aqueous samples was 2.5%. The results showed that DLLME is a very simple, rapid, sensitive, and efficient analytical method for the determination of trace amounts of formaldehyde in wastewaters and detergents, and suitable results were obtained.     

Approaches for prevention and environmental management of novel COVID-19

Environmental Science and Pollution Research - The World Health Organization (WHO) recognized a novel coronavirus as the causative agent of a new form of pneumonia. It was subsequently named...     

Interaction between meteorological parameters and COVID-19: an ecological study on 406 authorities of the UK

Environmental Science and Pollution Research - Understanding the factors affecting COVID-19 transmission is critical in assessing and mitigating the spread of the pandemic. This study investigated...     

A critical review of state-of-the-art electrocoagulation technique applied to COD-rich industrial wastewaters

Environmental Science and Pollution Research - Electrocoagulation (EC) is one of the emerging technologies in groundwater and wastewater treatment as it combines the benefits of coagulation,...     

Rapid photodegradation and detection of zolpidem over β-SnWO4 and α-SnWO4 nanoparticles: optimization and mechanism

Environmental Science and Pollution Research - We reported the tin (II) tungstate nanoparticles as the photocatalyst and sensor modifier that were synthesized via chemical precipitation reaction...     

Evaluation of the available strategies to control the emission of microplastics into the aquatic environment

Environmental Science and Pollution Research - No effective strategy has been found so far to control the emission of microplastics. The purpose of this article is to review the available control...     

Performance enhancement of a solar still using a V-groove solar air collector—experimental study with energy,exergy, enviroeconomic,and exergoeconomic analysis

Environmental Science and Pollution Research - This paper intended to evaluate the performance of a new design of solar still integrated with a V-groove solar air collector. In this system, an air...     

Ultrasensitive and selective 4-aminophenol chemical sensor development based on nickel oxide nanoparticles decorated carbon nanotube nanocomposites for green environment

Nickel oxide nanoparticles decorated carbon nanotube nanocomposites(Ni O·CNT NCs)were prepared in a basic medium by using facile wet-chemical routes. The optical,morphological, and structural properties of Ni O·CNT NCs were characterized using Fourier transformed infra-red(FT-IR), Ultra-violet visible(UV/Vis) spectroscopy, field-emission scanning electron microscopy(FESEM), X-ray energy dispersed spectroscopy(XEDS), X-ray photoelectron spectroscopy(XPS), and powder X-ray diffraction(XRD) methods. Selective4-aminophenol(4-AP) chemical sensor was developed by a flat glassy carbon electrode(GCE, surface area: 0.0316 cm~2) fabricated with a thin-layer of NCs. Electrochemical responses including higher sensitivity, large dynamic range(LDR), limit of detection(LOD), and long-term stability towards 4-AP were obtained using the fabricated chemical sensors. The calibration curve was found linear(R~2= 0.914) over a wide range of 4-AP concentration(0.1 nmol/L–0.1 mol/L). In perspective of slope(2 × 10~(-5)μA/μM), LOD and sensitivity were calculated as 15.0 ± 0.1 pM and ~ 6.33 × 10~(-4)μA/(μM·cm) respectively. The synthesized Ni O·CNT NCs using a wet-chemical method is a significant route for the development of ultrasensitive and selective phenolic sensor based on nano-materials for environmental toxic substances. It is suggested that a pioneer and selective development of 4-AP sensitive sensor using Ni O·CNT NCs by a facile and reliable current vs voltage(I–V)method for the major application of toxic agents in biological, green environmental, and health-care fields in near future.     

Sensitive and selective determination of phenylhydrazine in the presence of hydrazine at a ferrocene-modified carbon nanotube paste electrode

The determination of hydrazine derivatives is of special interest because they are toxic and widely used in industry, agriculture and explosives. Electrochemical analysis has become of growing importance in industrial process control, environmental monitoring, and different applications in medicine and biotechnology. In the present work, we used a carbon paste electrode modified by ferrocene and carbon nanotubes for simultaneous determination of phenylhydrazine and hydrazine. The modified electrode showed an excellent character for electrocatalytic oxidization of phenylhydrazine and hydrazine with a 310 mV separation of both peaks. Differential pulse voltammetric peak currents of phenylhydrazine and hydrazine increased linearly with their concentrations at the range of 0.85–700 and 16–800 μM, and the detection limits (3σ) were determined to be 0.6 and 14 μM, respectively. Here, we show that this electrode could be used as an electrochemical sensor for determination of phenylhydrazine and hydrazine in real samples (water and urine) with advantages such as short time of analysis, lack of pretreatment procedures and more cheaper in comparison with some routine analysis methods such as chromatography or spectroscopy. The modified electrode showed good reproducibility, remarkable long-term stability, and especially good surface renewability by simple mechanical polishing.