Ultra-Trace Determination of Phosphate Ion Based on Filtration-Dissolution and Flow-through Spectrophotometric Measurement
A sensitive spectrophotometric method for the determination of ultra-trace amounts of phosphate ion is proposed. The colored ion associate formed between molybdophosphate and Malachite Green (MG) was filtered through a tiny membrane filter (cellulose nitrate; poresize, 1.0μm; 9mm diameter), dissolved together with the membrane filter in 1cm(3) or less of Methyl Cellosolve; the absorbance of the solution was then measured at 627nm with a flow-through system equipped with an autosampler. The absorbance, the standard deviation and the relative standard deviation of the reagent blank were 0.0270, 0.0005 and 1.8%, respectively. A calibration graph was linear over the range from 0.018 to 1.0ng cm(-3) (1ppb) of phosphorus using 40cm(3) of sample solutions; the detection limit corresponding to two-times the standard deviation of the reagent blank was 3ppt of phosphorus. By using the proposed method, phosphate ion in pure water samples were determined.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.