Analysis of Chlorpromazine in Milk and Chicken Egg Extracts using Triple Quadrupole LC/MS/MS

Significance of the topic

The detection of chlorpromazine residues in animal-derived foods is critical to ensure consumer safety and regulatory compliance. Banned in livestock for food production, trace monitoring in milk and eggs helps prevent health risks and meets strict food safety standards.

Objectives and study overview

This study adopts a recent triple quadrupole LC/MS/MS method proposed by the Pharmaceutical Affairs and Food Sanitation Council to quantify chlorpromazine in milk and chicken eggs. It aims to validate method performance in real food matrices, focusing on sensitivity, linearity, and recovery.

Methodology

The sample preparation involves:

• Weighing 10 g of milk or egg;
• Double extraction with acetone and volume adjustment to 100 mL;
• SPE cleanup using a sulfonate-modified methacrylate copolymer mini-column;
• Eluate concentration to ~1 mL and final dilution with 0.1% formic acid/acetonitrile (3:2) to 5 mL.

Instrumental setup

Analysis was performed on a Shimadzu LCMS-8050 with conditions:

• Column: Shim-pack HR-ODS (150×2.1 mm, 3 μm) at 40 °C;
• Mobile phase: 0.1% formic acid in water/acetonitrile (72:28) at 0.2 mL/min;
• Injection volume: 2 μL;
• ESI-positive mode, MRM transitions m/z 319.10→86.15 (quantifier) and 321.10→58.10 (qualifier);
• DL temperature 250 °C, heating gas 15 L/min.

Results and discussion

Method sensitivity was demonstrated with a 10 ng/L limit of detection (LOD) at a 2 μL injection. Calibration over 10–1,000 ng/L yielded linearity (R2>0.9998). Blank matrices showed no interfering peaks. Spike-and-recovery tests at 20 ng/L (0.0001 mg/kg) produced recoveries of 103% (milk, RSD 5.7%) and 102% (egg, RSD 2.45%), confirming accuracy.

Advantages and practical applications

The streamlined prep reduces steps compared to traditional methods while maintaining high sensitivity. The LCMS-8050 platform enables reliable routine screening of chlorpromazine residues in dairy and egg products, supporting QA/QC and regulatory monitoring.

Future trends and opportunities

Further developments may include automation of SPE steps, reduced solvent use, and extension of this approach to other veterinary drugs. High-throughput workflows and miniaturized columns could enhance laboratory efficiency and sustainability.

Conclusion

The described triple quadrupole LC/MS/MS method offers robust, sensitive, and reproducible quantification of chlorpromazine in milk and eggs. It fulfills regulatory requirements and provides a practical solution for food safety laboratories.

References

1. Ministry of Health, Labour and Welfare Notification No. 370 (1959)
2. Ministry of Agriculture, Forestry and Fisheries Ordinance No. 44 (2013)
3. Shimadzu Application Note C202, Dec. 2019