Comparison of high-performance ion chromatography technique with microbiological assay of wyo-inositol in plant components of poultry feeds

Abstract

An ion chromatography technique (HPAEC-PAD) was employed for determination of inositol in plant components of feeds as an alternative to a microbiological assay. The study included analysis of total, free and dialysable inositol released from samples by an in vitro procedure simulating digestion in the gastrointestinal tract of birds. Inositol was separated on the high-performance anion-exchange CarboPack MAI column and monitored by the pulsed amperometric detection (PAD). As compared to the HPAEC-PAD technique, microbiological assay produced 2-3 fold lower values of total inositol, probably due to /wyo-inositol stereoselectivity of Saccharomyces cerevisiae ATCC 9080 analytical strain. The overall correlation coefficient was 0.989, 0.941 and 0.736 for total, free and dialysable inositol, respectively. Microbiological method of analysis rather than the HPAEC-PAD technique may be recommended for determination of dialysable myoinositol released from feed samples during in vitro digestions that simulate gastrointestinal tract of birds. The HPAEC-PAD technique was more sensitive, convenient and suitable for total inositol determination.