Evaluating System Robustness of a High-Sensitivity Triple Quadrupole LC/MS for PFAS Analysis in Food Matrix Over an Extended Period

Significance of Topic

Per and polyfluoroalkyl substances represent a critical group of emerging contaminants due to their persistence and health risks. Regulatory agencies worldwide are tightening limits on PFAS in food and environmental samples. High sensitivity and reliable performance of analytical platforms such as triple quadrupole liquid chromatography mass spectrometry are essential for meeting both current and anticipated future requirements in routine testing laboratories.

Objectives and Study Overview

This work aimed to evaluate the long term robustness of a high sensitivity triple quadrupole LC MS system for targeted PFAS analysis in a challenging food matrix. The study employed a streamlined experimental design to simulate continuous high throughput operation over three weeks, monitoring system performance with repeated injections of PFAS spiked salmon extract.

Methodology

Salmon tissue was homogenized and extracted using a QuEChERS based protocol followed by pass through cleanup on a PFAS selective cartridge. Extracts were spiked with native and isotopically labeled PFAS standards at trace levels. Performance monitoring injections were interleaved every 100 matrix injections without any maintenance or recalibration during the test period.

Instrumentation

• Agilent 1290 Infinity II liquid chromatograph
• Agilent 6495D triple quadrupole mass spectrometer
• C18 guard and analytical columns optimized for PFAS delay and separation
• Electrospray ion source operated in negative polarity

Main Results and Discussion

Over 13,700 matrix injections (~137 mL undiluted salmon extract) were performed continuously for three weeks. Raw peak area responses for PFOA and PFOS remained stable, within ±20 percent of their mean values. After internal standard correction, relative standard deviations were under 5 percent for both analytes. Routine calibration checks confirmed that mass axis and peak width remained within manufacturer specifications throughout the experiment. Visual inspection of inlet components showed matrix deposition but no significant contamination affecting performance.

Benefits and Practical Applications

These findings demonstrate that the evaluated LC MS system can sustain high throughput PFAS testing in complex food samples without frequent downtime or maintenance. Laboratories conducting routine compliance or research assays can expect uninterrupted operation, higher productivity, and reduced per sample costs.

Future Trends and Opportunities

Advancements in ion source design and insource cleanup may further extend maintenance intervals. Integration of automated tuning routines and real time performance diagnostics will enhance uptime. Emerging ambient ionization techniques may complement triple quadrupole assays for rapid screening.

Conclusion

The high sensitivity triple quadrupole LC MS platform exhibited exceptional robustness during an extended PFAS testing campaign in salmon matrix. Consistent signal stability and successful calibration without intervention support its application in demanding analytical environments.