A simple, quick and sensitive capillary electrophoretic technique has been developed for the pharmaceutical analysis of isoxazolylpenicillins (oxacillin, cloxacillin and dicloxacillin) at trace levels for the first time. This method comprises large-volume sample stacking using the electroosmotic flow (EOF) pump (LVSEP), separation using 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CD) as selective complex-forming background electrolyte additive, and direct UV detection. A complete resolution was achieved in the optimal background electrolyte containing 5.2 mM HP-beta-CD. LVSEP was successfully applied in their determinations to improve the sensitivity, where the EOF in the buffer zone was suppressed by using an acidic buffer with pH 3.6. The detection limits of the current technique were found to be 2.0 microg/L for each of the isoxazolylpenicillins based on the signal-to-noise ratio of 3. The curves of peak response versus concentration were linear from 5.0 to 400.0 microg/L with regression coefficients of 0.9982, 0.9986 and 0.9976, respectively. The interaction of isoxazolylpenicillins with HP-beta-CD was discussed. The association constants for complexes of HP-beta-CD with isoxazolylpenicillins were determined by electrophoretic method. The obtained association constants were 27.3, 34.9, and 48.5 M(-1), respectively, being proportional to their hydrophobic properties and steric hindrances. A simple and easy-manipulative sample preparation method was developed and validated by analyzing commercially available milk samples. It was found that with current sample preparation process and instrumentation system, 0.1 mL of milk sample is enough for the analysis of isoxazolylpenicillins to meet European Union (EU) guideline of 30 microg/kg.

A simple, quick, and sensitive capillary electrophoretic technique-large volume stacking using the electroosmotic flow (EOF) pump (LVSEP) - has been developed for determining ethylenediaminetetraacetic acid (EDTA) in drinking water for the first time. It is based on a precapillary complexation of EDTA with Fe(III) ions, followed by large-volume sample stacking and direct UV detection at 258 nm. The curve of peak response versus concentration was linear from 5.0 to 600.0 microg/L, and 0.7 to 30.0 mg/L. The regression coefficients were 0.9988 and 0.9990, respectively. The detection limit of the current technique for EDTA analysis was 0.2 microg/L with an additional 10-fold preconcentration procedure, based on the signal-to-noise ratio of 3. As opposed to the classical capillary zone electrophoresis (CE) method, the detection limit was improved about 1000-fold by using this LVSEP method. To the best of our knowledge, it represents the highest sensitivity for EDTA analysis via CE. Several drinking water samples were tested by this novel method with satisfactory results.

Airborne particulate matter has now become an issue in the global environment. In this study, the atmospheric PM 2.5 , organic carbon (OC), elemental carbon (EC) and water-soluble organic carbon (WSOC) were measured in the urban city of Tiruchirappalli, Tamil Nadu, India. The annual average concentration of PM 2.5 was observed in 76.1 μg/m 3 , Similarly, the seasonal average of PM 2.5 were 49.4 μg/m 3 in summer, 73.3μg/m 3 in Pre-monsoon, 86.1 μg/m 3 in winter and 87.9 μg/m -3 during monsoon respectively. The present study found that the annual average concentrations of PM 2.5 in Tiruchirappalli was significantly higher than the limit of 40 μg/m 3 prescribed in the National Ambient Air Quality Standards (Indian-NAAQS) and 10 μg/m 3 of that of the World Health Organization (WHO). While, the annual concentrations of OC, EC and WSOC were 8.9 μg/m 3 , 4.1 μg/m 3 and 3.1 μg/m 3 respectively. On seasonal average, the OC and EC concentrations ranked in the order of monsoon> winter>pre-monsoon > summer, which could be attributed to the combined effects of changes in local emissions and seasonal meteorological conditions. The secondary organic carbon (SOC) estimated by EC-tracer method was the highest in pre-monsoon (7.94 μg/m 3 ) followed by monsoon (6.60 μg/m 3 ), winter (6.04 μg/m 3 ) and summer (4.57 μg/m 3 ). Overall, results revealed that the mass concentration of PM2.5 bound carbonaceous fractions, and their contributions were varies by seasons. This study provides baseline information that can be exploited for policy formulation and mitigation strategies to control air pollution in south Indian urban cities.

The aim of this study is to investigate the distribution and sources of polycyclic aromatic hydrocarbons (PAHs) as per the priority list of USEPA, bound to fine particulate matter (PM2.5) prevalent in Tiruchirappalli, an urban city of India. The sampling was carried out for 24 h continuously in each station to study the PM2.5 deposition. The PAHs deposited on the filter paper was estimated using ultrasonic centrifuge solid-phase extraction method and further analyzed with gas chromatography mass spectroscopy (GC-MS). The results showed that the range of PAHs concentrations in the study period was between 1.0 and 90.20 ng/m 3. The seasonal variation of all the 16 PAHs varied from 38.78 ng/m 3 in monsoon, 32.06 ng/m 3 in winter,12.54 ng/m 3 in summer and 8.88 ng/m 3 pre-monsoon. The annual average concentration of PAHs observed was 22.51 ng/m 3 with PAHs of higher molecular weight in abundance accounting for almost 90.81 % while the PAHs of lower molecular weight contributing to 9.23 %.Higher PAHs levels of 35.41 ng/m 3 were recorded during cold months followed by 10.71 ng/m 3 during warm months. Diagnostic ratio source analysis and principal component analysis established that vehicular emissions and off-road combustion sources were the major sources. The mean benzo(a)pyrene toxicity equivalent calculated for samples was 2.83 ng/m 3 and the mean contribution of the carcinogenic potency of benzo(a)pyrene was observed to be 41.13 %.