Automated sample preparation coupled to sequential injection chromatography: On-line filtration and dilution protocols prior to separation

Sequential injection chromatography (SIC) is a valuable tool in analytical chemistry as it can combine the automation capabilities of low pressure continuous flow techniques and the separation power of HPLC into a single instrumental configuration. The present study reports an automated SI setup allowing on-line filtration and dilution of the samples before separation through a short monolithic column. The applicability of the procedure was evaluated by studying the behavior of acyclovir formulations under forced degradation conditions. Minimal sample preparation is required prior to analysis. Thorough validation of the on-line dilution SIC assay was carried out and proved its validity in terms of critical parameters such as precision, accuracy and robustness. The results were evaluated by parallel experiments and analysis using the procedure recommended by the USP based on conventional HPLC using particulate-based column.