Microflow liquid chromatography coupled to mass spectrometry--an approach to significantly increase sensitivity,...

Area of Science:

• Analytical Chemistry
• Environmental Science
• Food Safety

Background:

• Accurate pesticide residue analysis is crucial for food safety and regulatory compliance.
• Traditional methods often face challenges with sensitivity and matrix effects, impacting residue detection.
• Development of advanced analytical techniques is needed to overcome these limitations.

Purpose of the Study:

• To develop and validate a novel pesticide residue analysis method using microflow-liquid chromatography coupled to tandem mass spectrometry (microflow-LC-ESI-QqQ-MS).
• To evaluate the method's performance characteristics, including sensitivity, matrix effects, and robustness, for detecting 90 pesticide residues and their degradation products.
• To assess the method's applicability in routine analysis of food commodities, particularly organically produced samples.

Main Methods:

• Utilized a microflow-liquid chromatography system coupled with an electrospray ionization triple quadrupole mass spectrometer (microflow-LC-ESI-QqQ-MS).
• Employed a narrow-tip emitter for electrospray ionization, generating smaller droplets to enhance sensitivity.
• Validated the method for 90 pesticide residues and degradation products in tomato, pepper, and orange matrices, assessing performance metrics and robustness over 100 injections.

Main Results:

• Achieved significant sensitivity gains and a notable reduction in matrix effects due to sample dilution (up to 30-fold).
• Demonstrated method robustness with 100 consecutive injections without maintenance, indicating suitability for long analytical runs.
• Reported satisfactory quality control results and achieved Limit of Quantitation (LOQ) values mostly at 5 μg kg⁻¹ for analyzed pesticide residues.
• Successfully applied the method to routine analysis of 50 organically produced fruit and vegetable samples.

Conclusions:

• The microflow-LC-MS/MS method provides a highly sensitive and robust approach for pesticide residue analysis.
• The method effectively mitigates matrix effects, enabling accurate quantification in complex food matrices.
• Significant reductions in solvent consumption and analysis time were observed, making it an environmentally and economically advantageous technique for routine food safety monitoring.