Rapid and accurate phytate quantification in plant tissues and grains via ion chromatography: Validation and application

Phytate (inositol hexakisphosphate) represents 65-90% of total phosphorus in the grains, yet its accurate quantification in plant samples remains challenging. In this study, a novel ion chromatography method coupled with suppressed conductivity detection (IC-SCD) was developed for rapid phytate determination in 15 plant samples. These included two model plants ( N. tabacum and A. thaliana ), four crop plants ( O. sativa, B. rapa, S. lycopersicum, and T. aestivum ), four fern plants ( P. ensiformis, P. vittata, P. multifida, and P. cretica ), and five grain samples (maize, rice, barley, oat, and wheat). The IC-SCD method achieved a low detection limit of 0.2 mg/L (0.04 mg/g) and enabled effective phytate separation from interferences of inositol trisphosphate and common organic acid salts, including malate, tartrate, oxalate, and citrate, which are inadequately resolved by high-performance liquid chromatography. Compared with the Wade method, the phytate contents determined by IC−SCD were comparable in 5 grain samples (1.64−3.11 mg/g). However, much lower values were obtained in 10 plant tissues (0.20−1.14 vs. 6.67−8.01 mg/g), with P. vittata showing the highest phytate content. The data indicate that Wade method overestimates phytate in plant tissues due to organic acid salt interference. This study demonstrates that the IC−SCD method provides a reliable and cost-effective analytical approach for accurate phytate determination, supporting improved evaluation of phosphorus dynamics in plant and feed research. • Ion chromatography-suppressed conductivity detection (IC-SCD) method was developed; • IC-SCD enables rapid, accurate, and economic phytate quantification in plants; • Phytate is separated from major organic acid salts, avoiding matrix interference; • Accurate analysis across plant samples reveals species differences in phytate; • Wade method overestimates phytate due to strong organic acid–Fe 3+ interference.