A quick analytical method using direct solid sample introduction and GC-ECD for pesticide residues analysis in crops.

Area of Science:

• Analytical Chemistry
• Environmental Science
• Agricultural Science

Background:

• Pesticide residue analysis in crops is crucial for food safety and regulatory compliance.
• Traditional methods often involve time-consuming sample preparation steps, hindering large-scale screening.
• There is a need for rapid, reliable analytical techniques for on-site or high-throughput pesticide detection.

Purpose of the Study:

• To develop a simplified analytical method for the rapid detection of pesticide residues in solid crop samples.
• To enable quick screening of a large number of samples without extensive pre-treatment.
• To optimize gas chromatography (GC) parameters for direct solid sample introduction.

Main Methods:

• Development of a modified split/splitless injector for GC to handle direct solid sample introduction.
• Direct introduction of 10mg of solid crop sample without prior extraction or cleanup.
• Optimization of injector-port temperature, matrix removal, sample size, and oven temperature program.
• Analysis of six target pesticides: methyl parathion, fenitrothion, aldrin, dieldrin, endosulfan, and o,p'-DDT.

Main Results:

• The developed method allowed for direct solid sample introduction into GC, reducing analysis time.
• The modified injector effectively removed oxygen and low-boiling point matrices.
• Satisfactory recoveries for the six target pesticides were achieved in maize and rice samples.
• The relative standard deviation for the method was consistently below 15%.

Conclusions:

• The proposed direct solid sample introduction method is a quick and reliable approach for pesticide residue analysis in crops.
• This technique significantly simplifies the analytical workflow, facilitating large-scale screening.
• The method offers a valuable tool for enhancing food safety monitoring in agriculture.