Simultaneous Determination of Six Inorganic Anions in Animal Whole Blood Using Ion Chromatography With Suppressed...

A sensitive and robust ion chromatography method with suppressed conductivity detection (IC-CD) was developed and validated for the simultaneous quantification of six inorganic anions (fluoride, nitrite, bromide, nitrate, phosphate, and sulfate) in animal whole blood. The method employed a carbonate-bicarbonate eluent (4.5-mM Na₂CO₃, 0.8-mM NaHCO₃) at a flow of 1 mL/min and an anion-exchange column (4 × 250 mm, Dionex IonPac AS23 RFIC) to achieve baseline resolution of all analytes within a 30-min run. Sample preparation involved protein precipitation with ice-cold methanol followed by centrifugation, dilution, and filtration. The method demonstrated excellent linearity (R² = 0.9974-0.9998), with limits of detection (LODs) ranging from 0.27 to 2.96 mg/L. Accuracy was confirmed through recovery studies, yielding values between 99.4% and 118.2%. Intraday and interday precision, expressed as relative standard deviation (%RSD), was consistently below 10% for both peak areas and retention times. The developed IC-CD protocol offers several advantages over existing techniques, including minimal sample volume, simplified sample preparation, rapid analysis, and high reproducibility. This method provides a valuable application tool for assessing ionic balance, nutritional status, and environmental exposure in animal health monitoring and toxicological studies.