Acetate, phosphate, chloride and citrate in infusion solutions

Importance of topic

Accurate determination of key anions in infusion solutions is essential for ensuring patient safety and proper therapeutic efficacy. Monitoring acetate, phosphate, chloride, and citrate levels supports quality control in pharmaceutical production and clinical applications.

Objectives and overview

This study aimed to establish a straightforward ion chromatography method with direct conductivity detection for simultaneous quantification of acetate, phosphate, chloride, and citrate in an amino acid-based infusion solution.

Methodology and instrumentation

The infusion sample was diluted 1:105 in the chromatographic eluent. Separation was achieved on a Super-Sep Anion column (6.1009.000) using 3.0 mmol/L phthalic acid with 2% acetone at pH 4.2 (adjusted with TRIS). The mobile phase flow rate was 2.0 mL/min and the injection volume was 100 µL. Detection was performed via direct conductivity measurement.

Main results and discussion

All four anions were baseline-separated within a 13-minute run time. Measured concentrations in the infusion solution were: acetate 8 133 mg/L, phosphate 2 406 mg/L, chloride 4 186 mg/L, and citrate 4 690 mg/L. Peak shapes were sharp and resolution was sufficient to prevent coelution, demonstrating method specificity and sensitivity.

Benefits and practical applications

• Simultaneous quantification of multiple anions in a single run
• Minimal sample preparation through simple dilution
• High reproducibility and low detection limits suitable for routine QC
• Applicable to regulated pharmaceutical environments for compliance monitoring

Future trends and potential applications

Emerging enhancements may include coupling with mass spectrometry for greater selectivity, adoption of shorter or monolithic columns for faster analyses, and automation to enable high-throughput screening in clinical and industrial laboratories.

Conclusion

The developed ion chromatography method is robust, user-friendly, and well-suited for routine evaluation of acetate, phosphate, chloride, and citrate in infusion solutions, thereby supporting both quality assurance and patient safety.