Correction to 'Determination of carcinogenic herbicides in milk samples using green non-ionic silicone surfactant of cloud point extraction and spectrophotometry'.
TL;DR: This research presents a novel probabilistic procedure that allows for direct measurement of the response of the immune system to earthquake-triggered landsliding.
Abstract: A new cloud point methodology was successfully used for the extraction of carcinogenic pesticides in milk samples as a prior step to their determination by spectrophotometry. In this work, non-ioni...
Citations
More filters
TL;DR: In this article, a simple cloud-point extraction coupled to in-situ metathesis reaction of deep eutectic solvents method followed by high-performance liquid chromatography for rapid determination of neonicotinoid insecticide residues (i.e. thiamethoxam, clothianidin, imidacloprid, and thiacloprid) was developed.
35 citations
TL;DR: This is the first study that have investigated the use of magnetic nanoparticles coated activated charcoal modified with OFX 0309 surfactant for pretreatment of triazine herbicides in food samples analysis for simultaneous separation of organic pollutants.
17 citations
TL;DR: In this paper , the authors evaluated photolysis for 46 OMPs by a KrCl* excilamp and compared it with a low-pressure mercury UV lamp, and found that the enhanced photolyisation at 222 nm was mainly caused by strong light absorbance for non-nitrogenous, aniline-like, and triazine OMP, while notably higher quantum yield (4-47 times of that at 254 nm) occurred for nitrogenous OMP.
Abstract: Krypton chloride (KrCl*) excilamps emitting at far-UVC 222 nm represent a promising technology for microbial disinfection and advanced oxidation of organic micropollutants (OMPs) in water treatment. However, direct photolysis rates and photochemical properties at 222 nm are largely unknown for common OMPs. In this study, we evaluated photolysis for 46 OMPs by a KrCl* excilamp and compared it with a low-pressure mercury UV lamp. Generally, OMP photolysis was greatly enhanced at 222 nm with fluence rate-normalized rate constants of 0.2–21.6 cm2·μEinstein–1, regardless of whether they feature higher or lower absorbance at 222 nm than at 254 nm. The photolysis rate constants and quantum yields were 10–100 and 1.1–47 times higher, respectively, than those at 254 nm for most OMPs. The enhanced photolysis at 222 nm was mainly caused by strong light absorbance for non-nitrogenous, aniline-like, and triazine OMPs, while notably higher quantum yield (4–47 times of that at 254 nm) occurred for nitrogenous OMPs. At 222 nm, humic acid can inhibit OMP photolysis by light screening and potentially by quenching intermediates, while nitrate/nitrite may contribute more than others to screen light. Overall, KrCl* excilamps are promising in achieving effective OMP photolysis and merit further research.
References
More filters
TL;DR: The results demonstrated that hollow fiber-protected LPME was a fast, accurate, and stable sample pretreatment method that gave very good enrichment factors for the extraction of triazine herbicides from aqueous or slurry samples.
Abstract: A new microextraction technique termed hollow fiber-protected liquid-phase microextraction (LPME) was developed. Triazines were employed as model compounds to assess the extraction procedure and were determined by gas chromatography/mass spectrometry. Toluene functioned as both the extraction solvent and the impregnation solvent. Some important extraction parameters, such as effect of salt, agitation, pH, and exposure time were optimized. The new method provided good average enrichment factors of >150 for eight analytes, good repeatability (RSDs <3.50%, n = 7), and good linearity (r2 ≥ 0.9995) for spiked deionized water samples. The limits of detection (LODs) were in the range of 0.007−0.063 μg/L (S/N = 3) under selected ion monitoring mode. In addition to enrichment, hollow fiber-protected LPME also served as a technique for sample cleanup because of the selectivity of the membrane, which prevented large molecules and extraneous materials, such as humic acids in solution, from being extracted. The utiliz...
458 citations
TL;DR: This paper compares shape function (SF)-based and inverse distance weighting (IDW)-based spatiotemporal interpolation methods on a data set of PM2.5 data in the contiguous U.S. based on the error statistics results of k-fold cross validation, and finds the SF-based method performed better overall than the IDW-based methods.
Abstract: Appropriate spatiotemporal interpolation is critical to the assessment of relationships between environmental exposures and health outcomes. A powerful assessment of human exposure to environmental agents would incorporate spatial and temporal dimensions simultaneously. This paper compares shape function (SF)-based and inverse distance weighting (IDW)-based spatiotemporal interpolation methods on a data set of PM2.5 data in the contiguous U.S. Particle pollution, also known as particulate matter (PM), is composed of microscopic solids or liquid droplets that are so small that they can get deep into the lungs and cause serious health problems. PM2.5 refers to particles with a mean aerodynamic diameter less than or equal to 2.5 micrometers. Based on the error statistics results of k-fold cross validation, the SF-based method performed better overall than the IDW-based method. The interpolation results generated by the SF-based method are combined with population data to estimate the population exposure to PM2.5 in the contiguous U.S. We investigated the seasonal variations, identified areas where annual and daily PM2.5 were above the standards, and calculated the population size in these areas. Finally, a web application is developed to interpolate and visualize in real time the spatiotemporal variation of ambient air pollution across the contiguous U.S. using air pollution data from the U.S. Environmental Protection Agency (EPA)’s AirNow program.
231 citations
TL;DR: Matrix solid phase dispersion (MSPD) is a patented process for the simultaneous disruption and extraction of solid and semi-solid samples, which has proven to be particularly applicable for the analysis of drugs, pollutants, pesticides and other components in foods as discussed by the authors.
206 citations
TL;DR: The determination of phenylurea and triazine herbicides in milk based on microwave assisted ionic liquid microextraction (MAILME) coupled with high-performance liquid chromatographic separation was described and the proposed method was applied to the analysis of milk samples.
91 citations
01 Jan 2007
Abstract: A method based on cloud point extraction was developed to determine phthalate esters including di-ethyl-phthalate (DEP), di-(2-ethylhexyl)-phthalate (DEHP) and di-cyclohexyl-phthalate (DCP) in environmental water samples using high-performance liquid chromatography separation and ultraviolet detection (HPLC-UV). The non-ionic surfactant Triton X-114 was chosen as extraction solvent. The parameters affecting extraction efficiency, such as concentrations of Triton X-114 and Na2SO4, equilibration temperature, equilibration time and centrifugation time were evaluated and optimized. Under the optimum conditions, the method can achieve preconcentration factors of 35, 88, 111 and detection of limits of 2.0, 3.8, 1.0 ng/ml for DEP, DEHP and DCP in 10-ml water sample, respectively. The proposed method was successfully applied to the determination of trace amount of phathalate esters in effluent water of the wastewater treatment plant and the lixivium of plastic fragments.
89 citations