ISSN:
1618-2650
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Summary A highly sensitive and accurate fluorophotometric method is described for the determination of phosphate using the ion pair formation of molybdophosphate with Rhodamine 6G. This ion pair is floated at the phase boundary between ethyl ether phase and aqueous phase when the aqueous phase is adjusted to 0.38 mol/l sulphuric acid, 1.9 mmol/l ammonium molybdate and 3.8 Μmol/l Rhodamine 6G. After the phase separation, the floated ion pair is dissolved into the ethyl ether phase by the addition of methanol. The fluorescence intensity of the ion pair is measured at 548 nm with excitation at 530 nm. The calibration curve for phosphate is linear up to 100 ng of phosphorus with a correlation coefficient of 0.999. The relative standard deviation is 2.3% for 100 ng of phosphorus (n=11). Although arsenic(V) causes a positive error, no ions commonly existing in natural water, including silicate, interfere with the determination of phosphate. The proposed method was applied to the determination of phosphate-phosphorus in some natural waters and satisfactory results were obtained.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00481971
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