Flow-injection determination of retinol and tocopherol in pharmaceuticals with acidic potassium permanganate chemiluminescence.
A simple and rapid flow-injection method is reported for the determination of retinol, its derivatives and alpha-tocopherol by its enhancement effect on a potassium permanganate-formaldehyde chemiluminescence system in an acidic medium. Linear calibration graphs were obtained between 5.0 x 10(-8) to 5.0 x 10(-6) mol L(-1) for all-trans-retinol, 5.0 x 10.8 - 2.5 x 10(-6) mol L(-1) for all-trans-retinal, 5.0 x 10(-7) - 1.0 x 10.5 mol L(-1) for retinoic acid, 1.0 x 10(-7) - 5.0 x 10(-6) mol L(-1) for retinyl acetate and retinyl palmitate and 1.0 x 10(-8) - 5.0 x 10(-6) for alpha-tocopherol, with relative standard deviations (RSD; n = 4) in the range of 0.8 - 2.8%. The limits of detection (S/N = 3) were in the range of 5.0 x 10(-9) - 1.0 x 10(-7) mol L(-1) with a sample throughput of 100 h(-1). The influence of common ions, excipients in pharmaceutical preparations and related organic compounds were studied on the determination of retinol and alpha-tocopherol individually. The method was applied to determine retinol and alpha-tocopherol in pharmaceutical preparations, and the results obtained were in reasonable agreement with the amount labelled.
Waseem
Amir
A
Department of Chemistry, University of Balochistan, Quetta, Pakistan.
Rishi
Lubna
L
Yaqoob
Mohammad
M
Nabi
Abdul
A
D000143:Acids / Q000737:chemistry*; D017022:Flow Injection Analysis / Q000295:instrumentation / Q000379:methods*; D005557:Formaldehyde / Q000737:chemistry; D008163:Luminescent Measurements / Q000295:instrumentation / Q000379:methods*; D015394:Molecular Structure; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D011196:Potassium Permanganate / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D024505:Tocopherols / Q000032:analysis*; D014801:Vitamin A / Q000032:analysis*
D000143:Acids; D004364:Pharmaceutical Preparations; D011196:Potassium Permanganate; D014801:Vitamin A; D005557:Formaldehyde; D024505:Tocopherols