The selective enhancement of membrane introduction mass spectrometry for non-polar alkanes, alkenes, and aromatic hydrocarbon compounds by the application of acetonitrile as a chemical ionization reagent was investigated. Acetonitrile Cl is able to produce specific fragment ions for many of the compounds test and this can be used to identify and quantify the parent neutrals. This method provided relatively high detection limits of the test compounds. This method could potentially be useful for analytical applications such as the detection of non-polar hydrocarbons for environmental studies if CH3CN Cl/MIMS is coupled with a preconcentration method.
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The morphology of silver particles deposited on ITO-glass surface by pulse electrolysis in acetonitrile solutions of AgNO3 has been analyzed. The influences of potential value (E) as well pulse duration (τon) and pause (τoff) on the size and geometry of the particles has been discussed. It has been shown that in the range of 0.0 ≤ E ≤ −1.5 V at τon = 6 ms and 90 ≤ τoff ≤ 490 ms formation of silver particles (∼20–50 nm) and their agglomeration (∼0.2–2 µm) take place. The tendency to increase size of the particles in 3D has been observed with the increase of cathode potential. Decreasing of duty cycle leads to more discrete deposited particles. [...]
The main objective of the proposed study is to develop and validate a new stability indicating reverse phase HPLC gradient method for the simultaneous estimation of olmesartan medoxomil and chlorthalidone in combined dosage form. The method is optimized by using zorbax phenyl column (250 x 4.6 mm, 5 μ). For pump-A, ammonium dihydrogen orthophosphate and pump-B, acetonitrile: are used. Phosphate buffer pH was adjusted with orthophosphoric acid to 3.0. Water and acetonitrile (45:50) are used as diluent. The flow rate is 1.5 ml/min and the elutant is monitored at 220 nm with uv detector. The retention time of olmesatran medoxomil and chlorthalidone are 10.70 ±0.1 mins and 4.8 ± 0.1 mins respectively. Precision shows that % Relative standard deviation of olmesartan medoxomil and chlorthalidone is about 0.23 and 0.56 respectively. The percentage recoveries of both the drugs olmesartan medoxomil and chlorthalidone from the dosage formulation are 100.3% and 99.20% respectively. Linearity of olmesartan medoxomil and chlorthalidone is in the range of 10.0 to 60.0 μg/ml and 6.25 μg/ml respectively. Calibration curve shows good linearity and range. The correlation coefficient of olmesartan medoxomil and chlorthalidone is 0.999. And the results obtained for Robustness and Ruggedness are well within the acceptance criteria. The proposed method is found to be simple, rapid, accurate and precise. It is found to be economical and suitable for simultaneous determination of olmesartan medoxomil and chlorthalidone in pharmaceutical dosage form.
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