Online clean-up setup for the determination of non-fluorescent acidic pharmaceutical drugs in complex biological samples.

Analysis of acidic pharmaceuticals in complex biological samples is a challenging and formidable task due to the existence of interfering constituents within the sample matrices. Therefore, in order to avoid analytical column clogging and suppression/enhancement of signals of the analyte of interest, herein a simple, cost-effective and quick online ion chromatography based clean-up setup was introduced. This system was further coupled with a cost-effective homemade photochemically induced fluorimetric (PIF) setup for direct online conversion of non-fluorescent acidic pharmaceutical drugs into their respective fluorescent species. This advantageous system was favorably applied for the determination of four non-fluorescent acidic compounds in two complex biological samples (human serum and oral fluid) with minimum labor and organic solvent consumption. At optimized conditions, the developed method has shown good sensitivity, selectivity, satisfactory recoveries (88.68–102.14%) and low limits of detection (0.35–8.10 μg/L) with minimum or zero matrix effect. • An online SPE-IC system was designed for analysis of non-fluorescent acidic drugs. • Online clean-up setup was used for matrix removal from biological samples. • A post-column UV induced photochemical reactor was also fabricated with the IC system. • All drugs were isocratically separated and detected with a fluorescent detector. • Validated results were acceptable for all drugs in two complex biological samples. [ABSTRACT FROM AUTHOR]