SEQUENTIAL INJECTION CHROMATOGRAPHY FOR BIOFLUIDIC ANALYSIS: APPLICATION TO PROMETHAZINE ASSAY

In the current study, a newly developed sequential injection chromatograph (SIC) system is introduced to biochemical analysis. A new SIC method for promethazine assay is provided. The method was optimized, validated, and applied to human urine and serum, in addition to pharmaceutical formulations. Trifluphenazine was used as an internal standard. The 23 full-factorial design was adopted to screen the effect of mobile phase composition on separation efficiency, retention time, peak height, and baseline. The separation was conducted onto C18 monolithic column (4.6 x 25 mm) using 30 mmol/L phosphate:acetonitrile (50:50, v/v) at pH 4.0. The detection was carried out by miniaturized fiber optic spectrometric devices set at 250 nm. The limit of detection in biofluids was =23 ng/mL. The sensitivity was improved by optimizing the mobile phase composition, using a short monolithic column and a large sample volume (30 mu L), in addition to preconcentration obtained by solid-phase and liquidliquid extractions. Additionally, good recoveries (90.798.3%) in all types of samples were obtained. The remarkable advantages of the proposed SIC method are rapidity and simplicity, in addition to affordability in terms of instrumentation cost and reagent consumption.