This study investigates the effect of landfill age on landfill leachate characteristics; two aspects are focused here. One is ultraviolet absorbance at 254 nm (UV(254)) property, as the discharge of landfill leachates to publically owned treatment works can cause interference with UV(254) disinfection. The other is biorefractory organic nitrogen in leachates, as it can contribute to effluent nitrogen making it difficult to meet stringent effluent nitrogen regulations. To study variation in UV(254)-absorbing organic carbon and organic nitrogen, leachate samples ranging from cells with ages 2 to 30 y from a large landfill in Kentucky, were collected and fractionated on a basis of their molecular weight and chemical nature into humic acids, fulvic acids and a hydrophilic fraction. The effectiveness of long term landfilling and membrane treatment for organic matter and organic nitrogen removal was examined. Humic materials, which were the major UV(254)-absorbing substances, were mainly >1 kDa and they degraded significantly with landfill age. The hydrophilic organic fraction, which was the major contributor to organic nitrogen, was mainly <1 kDa and it became increasingly recalcitrant with landfill age. This study provides insight into the characteristics of the different leachate fractions with landfilling age that might aid the design of on-site leachate treatment techniques.
A simple, rapid, precise, sensitive and reproducible reverse phase high performance liquid chromatographic (RP-HPLC) method for determination of Telmisartan (TELM) in tablet dosage form was developed and validated. Chromatographic separation was achieved on a 250 × 4.6 mm, 5µ, Waters symmetry column in gradient mode, with mobile phase consisting of a mixture of solution (10 mM potassium dihydrogen phosphate, pH 3.5 ± 0.01): acetonitrile (64:40) was used. The quantitation performed at flow rate of 1.0 mL/min at 230 nm and run time was 12 min. The analytical method was validated as per ICH guideline for linearity, accuracy, precision, specificity, limit of detection, limit of quantification, robustness and stability and method can be extended to the analysis of TELM in tablet formulations. The relative standard deviation values for precision was less than 2%, and % recovery was greater than 98% for TELM. The drug undergoes oxidative degradation, thermal degradation and in alkali medium.
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