Method used for detecting 2,4-dichlorophenoxyacetic acid residue in fruits and vegetables

Abstract

The invention discloses a method used for rapidly detecting 2,4-dichlorophenoxyacetic acid (2,4-D) residue in fruits and vegetables via surface enhanced Raman spectroscopy (SERS). According to the method, gold sol is prepared via reduction of chloroauric acid with trisodium citrate; a 2,4-D-containing solution to be detected is mixed with gold sol; a portable Raman spectrometer is adopted for Raman spectrum scanning so as to obtain the surface enhanced Raman spectrum of 2,4-D; the characteristic peaks of 2,4-D can be observed at 1159cm<-1>, 838 cm<-1>, 890 cm<-1>, 718 cm<-1>, 1256 cm<-1>, 1308 cm<-1>, 1445 cm<-1>, and 1591 cm<-1>, and the peak strength of the characteristic peak at 838 cm<-1> is used for quantitative determination of the content of 2,4-D. According to the method, SERS is adopted to develop the method used for rapid, accurate, portable, and simple detection of 2,4-D residue, and the method is suitable for food safety on-site real-time rapid screening.

Description

technical field [0001] The invention belongs to the field of food safety monitoring, and in particular relates to a detection method for 2,4-dichlorophenoxyacetic acid residues in fruits and vegetables. Background technique [0002] 2,4-Dichlorophenoxyacetic acid (2,4-D) is a low-toxicity pesticide according to my country's pesticide toxicity classification standards, and has been registered in some vegetables and grains in my country. 2,4-D has strong biological activity on plants, and is a kind of efficient, systemic and highly selective herbicide and plant growth regulator. At high concentration, 2,4-D is a broad-spectrum herbicide, which is widely used in grass crops such as rice, corn, wheat, broad-leaved weeds in lawns and pastures; at low concentration, 2,4-D acts as Plant growth regulators can promote crop growth, increase fruit setting rate, increase fruit size, etc. In addition, as a food additive, 2,4-D is also a widely used fruit antiseptic and preservative, mai...

AI Technical Summary

Problems solved by technology

2,4-D is difficult to degrade in nature, so 2,4-D is easy to leach and migrate into water and soil, and then accumulate in organisms, which is harmful to human health and natural ecological environment

Because it contains a strong polar carboxyl group, the chromatographic peaks are tailed when the first two methods are directly detected, and the analysis sensitivity is low. In order to improve the volatility of the weak acid, it needs to be derivatized into an ester before detection

The introduction of derivatization makes the operation cumbersome and time-consuming

Liquid chromatography analysis does not require derivatization, but the pretreatment and purification requirements are strict and the operation is cumbersome, so it is not suitable for on-site detection and analysis of a large number of samples

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