Selective Detection of Paraquat in Adulterated and Complex Environmental Samples Using Raman Spectroelectrochemistry

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Electrochemistry

Background:

• Counterfeit and adulterated pesticides pose risks to agriculture and consumer safety.
• Rapid detection methods are needed to identify banned or harmful agricultural chemicals.
• Raman spectroscopy and electrochemical techniques show promise for pesticide analysis.

Purpose of the Study:

• To evaluate the efficacy of spectroelectrochemical measurements for identifying the herbicide paraquat.
• To determine optimal conditions for selective paraquat detection using coupled techniques.
• To assess the technique's performance in complex sample matrices.

Main Methods:

• Coupling a potentiostat with a Raman spectrograph for spectroelectrochemical measurements.
• Applying a potential of -0.70 V during Raman spectroscopic analysis.
• Testing the detection of paraquat in various matrices, including tap water, apple, and green cabbage, alongside other pesticides.

Main Results:

• Applying -0.70 V during measurements enabled highly selective Raman spectra, emphasizing paraquat's primary vibrational bands.
• The selective Raman signal of paraquat was successfully identified in complex samples.
• Detection was effective even in the presence of other pesticides like diquat, acephate, and glyphosate.

Conclusions:

• Spectroelectrochemical measurements offer a selective and reliable method for detecting paraquat.
• This technique has significant potential for identifying pesticides in diverse and complex real-world samples.
• The findings support the use of this method for ensuring agricultural product safety and authenticity.