Spatial pattern of groundwater arsenic contamination in Patna, Saran, and Vaishali districts of Gangetic plains of Bihar, India.

Groundwater is an essential source of drinking as well as irrigation water. It has recently become a significant challenge to maintain good and safe drinking water for all living beings. The continuous supply of arsenic detected in groundwater poses a severe health problem and has adverse effects on humans and the ecosystem. Researchers also identified arsenic contamination globally across various regions. However, a few studies also identified that the groundwater of Patna, Saran, and Vaishali districts of Bihar is intoxicated by arsenic. To assess the toxic level of arsenic in groundwater, samples from various GPS-based pointed locations were collected from the study area using a GARMIN GPS device. The total concentration of arsenic in drinking water (mostly traces of arsenic, level of µg L-1 or less) can be detected only by sophisticated analytical techniques such as ICP-MS, GF-AAS, and HG-AAS. The standard procedures were followed to determine quality attributes in groundwater. Arsenic contamination persists in most areas and exceeds the permissible limits prescribed by the World Health Organization (WHO), negatively impacting the health of more than 10 million people in the state. The 90.47% and 85.71% groundwater samples of the study area exceeded the permissible limit of the WHO (0.01 mg L-1) and Bureau of Indian Standards (BIS (0.05 mg L-1), respectively. The analyzed data was obtained, and variability was noticed in total arsenic concentrations ranging from 0.002 to 7.801 mg L-1, with a mean value of 0.87 mg L-1. Similarly, the water quality attribute like total dissolved solids were identified in 14.28% of samples, which crossed 201 to 1026 mg L-1, with a mean value of 375.33 mg L-1.

Dissipation study of difenoconazole in/on chili fruit and soil in India.

One field experiment was conducted with Difenoconazole (25% EC) on chili crop during December 2009 to January 2010 at two different locations of West Bengal and Maharashtra. The main objective was to understand the residue and persistence behaviour of fungicide difenoconazole in chili fruit and soil samples. Difenoconazole was applied in chili field at 50 mL and 100 mL/100 liter of water. Its residue was analyzed by using LC-MS/MS and it dissipated in chili fruit and soil following first order kinetics. The half life values of difenoconazole were found in the range 2.15-2.32 days and 4.68-8.09 days for chili fruit and soil, respectively.

Ligand centered radical pathway in catechol oxidase activity with a trinuclear zinc-based model: synthesis, structural characterization and luminescence properties.

A new trinuclear zinc(II) complex, [Zn3(L)(NCS)2](NO3)2·CH3OH·H2O (1), of a (N,O)-donor compartmental Schiff base ligand (H2L=N,N'-bis(3-methoxysalicylidene)-1,3-diamino-2-propanol), has been synthesized in crystalline phase. The zinc(II) complex has been characterized by elemental analysis, IR spectroscopy, UV-Vis spectroscopy, powder X-ray diffraction study (PXRD), (1)H NMR, EI mass spectrometry and thermogravimetric analysis. PXRD revealed that 1 crystallizes in P-1 space group with a=9.218 Å, b=10.849 Å, c=18.339 Å, with unit cell volume is 2179.713(Å)(3). Fluorescence spectra in methanolic solution reflect that intensity of emission for 1 is much higher compared to H2L and both the compounds exhibit good fluorescence properties. The complex 1 exhibits significant catalytic activities of biological relevance, viz. catechol oxidase. In methanol, it efficiently catalyzes the oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC) to corresponding quinone via formation of a dinuclear species as [Zn2(L)(3,5-DTBC)]. Electron Paramagnetic Resonance (EPR) experiment suggests generation of radicals in the presence of 3,5-DTBC and it may be proposed that the radical pathway is probably responsible for conversion of 3,5-DTBC to 3,5-DTBQ promoted by complex of redox-innocent Zn(II) ion.