Method for the determination of total components of o-phenylphenol and methrin in insecticides - Master's thesis - Dissertation

Gas chromatography is a powerful analytical technique used for the identification and quantification of various compounds in complex mixtures. In the context of insecticides, this method is particularly useful for analyzing multiple active ingredients present in sanitary products. The study focuses on the determination of seven key components: o-phenylphenol, methrin, dextromethrin, propymethrin, acetylidene, cypermethrin, and an additional compound, with dibutyl phthalate serving as an internal standard.

The analysis was conducted using a gas chromatograph equipped with a hydrogen flame ionization detector (FID), paired with an HP-1 capillary column (30m × 0.32mm × 0.25μm). This setup ensures high resolution and sensitivity, making it ideal for detecting trace amounts of these compounds. The linear correlation coefficients for each component were found to be above 0.998, indicating strong linearity across the tested concentration ranges.

Standard deviations for the measurements were low, ranging from 0.005 to 0.04, which reflects good precision. The coefficient of variation (CV) was also within acceptable limits, with values between 2.7% and 8.5%. The average recovery rate ranged from 99.81% to 100.61%, demonstrating the accuracy and reliability of the method.

This method allows for efficient screening and qualitative analysis of insecticide products, enabling quick decision-making regarding product quality. Since no single product contains all seven components simultaneously, the method can be adapted by adjusting operating conditions to achieve optimal separation and detection. This flexibility makes it suitable for use in different manufacturing settings where analytical methods may vary.

In recent years, the production of sanitary insecticides has grown rapidly, especially in regions like Shanghai, where over 40 manufacturers are active. However, there remains a lack of standardized analytical procedures. By developing a multi-component determination method, this study contributes to improving quality control and ensuring the safety and efficacy of these products.