Modified QuEChERS method for 24 plant growth regulators in grapes using LC-MS/MS

Area of Science:

• Agricultural Chemistry
• Analytical Chemistry
• Food Safety

Background:

• Plant growth regulators (PGRs) are crucial in viticulture for yield and quality.
• Accurate monitoring of PGR residues in grapes is essential for consumer safety and regulatory compliance.
• Existing analytical methods may lack the sensitivity or scope for comprehensive PGR analysis in complex matrices like grapes.

Purpose of the Study:

• To develop and validate a multiresidue analytical method for 24 plant growth regulators in grapes.
• To ensure the method's suitability for routine monitoring of PGR residues.
• To assess the method's performance across different grape varieties.

Main Methods:

• Extraction of 24 plant growth regulators using a modified Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method.
• Detection and quantification via liquid chromatography-tandem mass spectrometry (LC-MS/MS).
• Method validation including recovery studies, matrix effect evaluation, limit of quantification, trueness, and precision using matrix-matched calibrations.

Main Results:

• High determination coefficients (r² > 0.995) were achieved for all compounds.
• The limit of quantification ranged from 0.1 to 5 ng/mL.
• Intra-day and inter-day recoveries were within acceptable ranges (70.2-112.6% and 67.5-101.8%, respectively), with relative standard deviations below 20%.

Conclusions:

• The developed LC-MS/MS method is sensitive, precise, and accurate for multiresidue analysis of 24 plant growth regulators in grapes.
• The method demonstrated robustness across different grape varieties.
• The validated method is suitable for routine monitoring of plant growth regulator residues in grapes, aiding in food safety assurance.