Novel sample double dilution calibration method for determination of lithium in biological samples using automatic flow system with in-syringe reaction

Talanta. 2024 May 1;276:126177. doi: 10.1016/j.talanta.2024.126177. Online ahead of print.ABSTRACTA novel sample double dilution calibration method (SDDCM) and an automatic flow system with in-syringe reaction and spectrophotometric detection were developed for determining lithium in biological samples. The method is based on the reaction of lithium with Thorin in an alkaline medium and the signal was measured at 480 nm. The reaction was performed simultaneously for both standards and samples in three syringes of the automatic flow system. The method was validated and successfully applied to the determination of lithium in synthetic and pharmaceutical samples, with results consistent with the ICP OES method. The novel calibration method, developed for the determination of lithium in biological samples, uses a sample with two dilution degrees. Using the method, the concentration of the analyte is determined by relating the signal for a less diluted sample to the calibration plot for a more diluted sample and vice versa. The implementation of the calibration method was facilitated by preparing solutions directly in the flow system. The use of two sample dilutions makes it possible to determine the analyte in the sample without preliminary preparation. Moreover, obtaining two results based on signals for a sample diluted to different degrees allows them to be verified for accuracy. The proposed approach was successfully verified by the determination of lithium in certified refer...

Source: Talanta - May 8, 2024 Category: Chemistry Authors: Justyna Paluch Karolina Mermer Justyna Kwiatkowska Marek Kozak Joanna Kozak Source Type: research