Development of the CE-C4D method for determination of organic acids in infants faeces using an in-house built instrument.

[Display omitted] • SCFAs, crucial for health, result from bacterial fermentation of dietary fibres. • CE-C4D method for SCFAs analysis in infants' faeces was developed. • Polybrene dynamic capillary coating enables the separation of SCFAs isomers. • Analysis of faeces gives insight into microbial metabolism in infants' intestines. Short-chain fatty acids (SCFAs) are a major group of products produced during colonic bacterial fermentation of nondigestible carbohydrates demonstrating several important functions, e.g. regulating the immune system activity or the lipid metabolism. A detailed profile and concentration characterization of SCFAs in infant faeces is essential for expanding knowledge regarding the role of SCFAs in infant physiology and pathophysiology. This research presents the development and validation of a capillary electrophoresis method with a contactless capacitively coupled conductivity detector (CE-C4D) for the analysis of SCFAs and succinic and lactic acids in infant faeces. The study focused on optimizing the background electrolyte, mainly dynamic capillary coating with polybrene, and utilizing cyclodextrins to achieve efficient separation. Validation parameters, such as linearity (0.993 – 0.998), limits of detection and quantification (LOD: 0.10 – 0.89 μg/mL; LOQ: 0.35 – 2.97 μg/mL), intra- and inter-day precision (1.71 – 5.69 % and 1.11 – 12.5 %, respectively), injection repeatability (0.91 – 5.70 %), trueness (-12.8 – 3.80 %), and matrix effect (78.8 – 108.6 %), were assessed and the method was found suitable for the purpose. The demonstrated method was successfully applied to determine nine organic acids in faecal samples. [ABSTRACT FROM AUTHOR]