Development of new methodologies for rapid determination of oxidizable and reducible organic compounds using batch injection analysis
Abstrakt
Batch injection analysis (BIA) offers many advantages, e.g., rapid analysis, high reproducibility, sufficient selectivity, and minimal sample and reagent consumption. The development of a new method using BIA with amperometric detection (BIA-AD) for sensitive determination of chlorpromazine is described in this contribution.
The following parameters were optimized within the method development: pH of media (supporting electrolyte), detection potential, rate of dispense, and volume of dispense. Under the optimized conditions (pH = 6, detection potential of 700 mV, dispense rate of 286.3 μL s, injected volume of 50 μL), a linear calibration dependence of chlorpromazine was measured at a screen-printed carbon electrode in the concentration range 1-1000 μmol L, with a limit of quantification 2.7 μmol L.
Applicability of the newly develo-ped method was verified on determination of chlorpromazine in pharmaceutical formulation Plegomazine with satisfactory results. It is worth mentioning that air oxygen needs to be removed in BIA-AD from analyzed solutions while reducible compounds are determined.
One possible solution to overcome this complication is shown in experiments with metronidazole, where adding solid sodium sulfite as a reductive agent shows comparable results to the traditional oxygen removal with nitrogen gas.