Automated determination of selected water-soluble vitamins in tablets using a bench-top robotic system coupled to reversed-phase (RP-18) HPLC with UV detection.

The determination of folic acid, nicotinamide, nicotinic acid, riboflavin, riboflavin-5'-phosphate, pyridoxine and thiamine in tablets has been successfully automated using a bench-top robotic system (Zymark Tablet Processing Workstation II) coupled to reversed-phase (RP-18) HPLC with UV-detection. The new automated methods have been validated and were found to be applicable in routine analysis for all common types of multivitamin tablets. The precision is exemplified by relative standard deviations of 5.4% for folic acid, 2.1% for nicotinamide, 1.6% for pyridoxine, 0.7% for riboflavin and 1.1% for thiamine using film-coated tablets as sample. Mean recoveries obtained during spiking experiments were in the range of 95.2-103.9%.