Search

A new multi-residue method using gas chromatography–mass spectrometry electron ionization selective ion monitoring mode (SIM) has been developed for the simultaneous determination of eight 1,3,5-triazine herbicides such as 1,3,5-triazine-2,4-diamine (atrazine), ametryn, prometryn, propazine, terbuthylazine, terbutryn, and simazine simetryn in water and soil samples. Quantification is done using lindane (gamma benzene hexachloride) as an internal standard. A specific Capillary DB-Wax column of 30 m length, 0.32 mm internal diameter, and 0.25 µm film thickness is used for the separation of eight 1,3,5-triazine-2,4-diamine. The method was applied for the determination of residues in groundwater and soil samples. The lowest detection limit by GC-MS-SIM (selective ion monitoring mode) is 0.1 pg/mL. Recovery in water samples is in the range of 93–103%, and in soil samples, 91–102% for different individual compounds. Forty-five groundwater and soil samples were collected in and around Kancheepuram district in Tamilnadu (India), and they were analyzed for the respective residues. A detailed discussion of the GC-MS analysis results has been presented. [ABSTRACT FROM AUTHOR]

Industrial areas play an important role in the urban ecosystem. Industrial site environmental quality is linked to human health. Soil samples from two different cities in India, Jamshedpur and Amravati, were collected and analyzed to assess the sources of polycyclic aromatic hydrocarbons (PAHs) in industrial areas and their potential health risks. The total concentration of 16 PAHs in JSR (Jamshedpur) varied from 1662.90 to 10,879.20 ng/g, whereas the concentration ranged from 1456.22 to 5403.45 ng/g in the soil of AMT (Amravati). The PAHs in the samples were dominated by four-ring PAHs, followed by five-ring PAHs, and a small percentage of two-ring PAHs. The ILCR (incremental lifetime cancer risk) of the soil of Amravati was lower compared to that of Jamshedpur. The risk due to PAH exposure for children and adults was reported to be in the order of ingestion > dermal contact > inhalation while for adolescents it was dermal contact > ingestion > inhalation in Jamshedpur. In contrast, in the soil of Amravati, the PAH exposure path risk for children and adolescents were the same and showed the following order: dermal contact > ingestion > inhalation while for the adulthood age group, the order was ingestion > dermal contact > inhalation. The diagnostic ratio approach was used to assess the sources of PAHs in various environmental media. The PAH sources were mainly dominated by coal and petroleum/oil combustion. As both the study areas belong to industrial sites, the significant sources were industrial emissions, followed by traffic emissions, coal combustion for domestic livelihood, as well as due to the geographical location of the sampling sites. The results of this investigation provide novel information for contamination evaluation and human health risk assessment in PAH-contaminated sites in India. [ABSTRACT FROM AUTHOR]

In the present study, calcium cobalt oxide-based ceramic oxide (Ca3Co4O9±δ) is synthesized by various reducing agent method by metal complex-assisted sol–gel assisted followed by combustion method using various reducing agents. The reducing agents adopted in the study are citric acid, starch polymer, and polyethylene glycol. The detailed structural and surface characterizations of as-prepared Ca3Co4O9+δ have demonstrated by XRD, TGA, and diffuse UV–visible spectral analysis. Hydrothermal method-prepared Iron-doped Ca3Co4O9± δ ceramic shows the Nanorods’ morphology. Electrical properties such as conductivity, Hall co-efficient, and electron mobility studies have been demonstrated. The density of the prepared materials by changing the stoichiometry ranges from 2.72 g/cm3 (relative density 55%) to 2.91 g/cm3 (relative density 58.9%). The density is found to be improved by decreasing the amount of calcium. The higher density is obtained for Ca2.90 Co3.91O9±δ which is 2.91 g/cm3 (58.9% of theoretical density). The effect of foreign metal ion doping in bulk calcium carbonate has studied and compared their electronic properties. The various reducing agent method-prepared Ca3Co4O9±δ shows the promising thermoelectric features. Polymer method-prepared Ca3Co4O9±δ sample with various transition metal ion substitution shows (calcium-doped ceramic oxide) the higher electron mobility and conducting activity. [ABSTRACT FROM AUTHOR]

CoAl2O4 and Zn:CoAl2O4 nanoparticles (NPs) were synthesized via microwave combustion process (MCP) and L-alanine used as fuel. The average crystallite size is found in the range of 10–18 nm. Spherical aggregated particle morphology is obtained for synthesized sample and the same confirmed by HR-SEM images and nonexistence of impurities in the prepared samples were confirmed by EDX spectra. The band gap values of the prepared samples were found to be in the range of 3.35–2.32 eV. Further in FTIR spectra a couple of strong absorption bands observed which lie in the range of 500–1100 cm−1, ensuring the formation of cubic spinel structure. Thermal studies confirmed the weight loss and exothermic transitions in pure and Zn2+ ion doped cobalt aluminate samples. The prepared Zn ion modified cobalt aluminate samples exhibited diamagnetic magnetic characteristics at room temperature and the same have been confirmed. The prepared Zinc ion modified cobalt aluminate spinel structure samples exhibited diamagnetic magnetic characteristics at room temperature and the same have been confirmed by the Magnetization–Field (M − H) hysteresis curves. The obtained images confirm the facile formation of crystallized grains comprising of pores and agglomerated coalescence morphology. Additionally, tiny secluded grains with pores and pore-walls ensuing from fused grains with discrete grain boundaries are noticed. [ABSTRACT FROM AUTHOR]