FLOW-INJECTION COLORIMETRIC METHOD FOR THE
ASSAY OF VITAMIN-C IN DRUG
FORMULATIONS USING TRIS,1-10-PHENANTHROLINE
IRON(III) COMPLEX AS AN
OXIDANT IN SULFURIC-ACID MEDIA
SULTAN, SM; ABDENNABI, AM; SULIMAN, FEO
ELSEVIER SCIENCE BV, TALANTA; pp: 125-130; Vol: 41
King Fahd University of Petroleum & Minerals
http://www.kfupm.edu.sa
Summary
A simple, fast and accurate colorimetric flow injection (FI) method suitable for the
assay of vitamin C in drug formulations was proposed. In the method, vitamin C was
injected into a flowing stream of iron(III) and then mixed with 1,10-phenanthroline in
0.05M sulphuric acid media. The mixture was allowed to react in a 45-cm long coil
and the resulting solution of tris, 1-10-phenanthroline-iron(II) complex was monitored
at 510 nm. The method was adopted by fully investigating the kinetics of the reaction
and proposing a suitable mechanism. A throughput of 100 samples per hour was
achieved with a relative standard deviation of 0.88% for vitamin C concentration
range of 100-400 ppm.
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Copyright: King Fahd University of Petroleum & Minerals;
http://www.kfupm.edu.sa
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Copyright: King Fahd University of Petroleum & Minerals;
http://www.kfupm.edu.sa