Metal Ions In Plant Esterase Inhibition Of Activation Analysis

The invention of pesticides, for the benefit of their own, but also endanger the environment and human health. China is a large agricultural country, pesticide production and use are busiest in the world. At present, China mainly organophosphorus pesticide pesticide-based, and many species are being used are of highly toxic drugs. Pesticide residues in the environment, food enters the body endanger human health. Therefore, rapid and sensitive detection of pesticide residues is to prevent harm prerequisite. The technology is a rapid inhibition test technology. This paper summarizes previous work experience, based on the plant esterase inhibition for the current sensitivity is not technically exist, such as the problem of high and seek a solution way.Inhibition of plant esterase reagent performance of the two compare, contrast the reagent 1 (acetic acid-β-naphthol) and reagent 2 (2,6-dichloro-acetyl indophenol) performance. Reagent 1 itself in 4℃for 24 hours that the change of color takes place, poor stability, while reagent 2 under the same conditions, save 1 month and no significant color change. Reagent 1 and reagent 2 on the optimal temperature of enzymatic reaction were 35℃, optimum pH are 6.5, the best reaction time was 10min and 15 minutes. In the above optimal conditions, methyl parathion (JJDLL) as enzyme inhibitors, analyzed the effect of two display agent, JJDLL esterase inhibition rate of the plant with its concentration on the relationship between the number of conducted line of fitting, reagent 1 fitting equation y=8.105x+74.79889, linear correlation index R=0.90291, reagent 2 fitting equation y=10.9316x +74.25222, the linear correlation index R=0.99024, in terms of slope or from the linear correlation, and reagent 2 performance than the reagent; in tag recovery experiments the recovery of reagent 2 is also much higher than the reagent 1. In contrast, the stability of reagent 2, sensitivity, precision, higher than the reagent 1, it is recommended reagent 2.Co2+ in the plant esterase inhibition method for the determination of organophosphorus pesticide residues in the activation of. Given the existence of plant esterase method the problem of low sensitivity, consider the use of metal ions on the activation of the enzyme increased the activity of the enzyme and thus improve the detection sensitivity. The best experimental conditions:The reagent 2 (2,6-dichlorophenolindophenol), maximum absorption wavelength is 605nm, the color the best time for 15min, the temperature 35℃, pH6.5,5% of the diluted enzyme the amount of 0.2mL, 0.01mol/L of Co2+ solution 0.6mL. Under the optimum conditions, the determination of JJDLL esterase inhibition rate of the plant and its concentration on the relationship between the number and the linear fit, obtained after adding Co2+ fitting equation y= 12.55333x +78.62889, the linear correlation index R=0.99809, and the previous experiment, the color contrast agent fitting equation 2 shows that after the accession of Co2+ sensitivity and accuracy were significantly improved; tag recovery experiments by adding Co2+ did not increase after the rate was significantly higher than Co2+ in the recovery. Thus, Co2+ activation of plant esterases to analyze the sensitivity and precision have been increased significantly. Co2+ present analysis of plant esterase inhibition mechanism of activation remains to be further studied.