Analysis of Gibberellic Acid and Forchlorfenuron in Fruits

• Main Authors: Miao, Hsin-Yin, 苗馨尹
• Other Authors: Hung, Lang-Bang
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/79923921885546598264

碩士 === 國立臺灣海洋大學 === 食品科學系 === 104 === Gibberellic acid (GA3) and forchlorfenuron (CPPU) are commonly used as the plant growth regulator. With the increasing usage of GA3 and CPPU, their safety have been attracted to people’s attention. If high concentration of growth regulator is left on the crop after harvest, it will be hazardous to food safety and environment. The purpose of this study was to establish a high performance liquid chromatography (HPLC) method with ultraviolet (UV) detection to determine the residues amounts of GA3 and CPPU in fruits. The optimum extraction method was also investigated. With an InertSustain® C18 column and UV detection under 210 nm, GA3 and CPPU could be separated effectively when using acetonitrile and 0.1% phosphoric acid solution as the mobile phase to do gradient elution. Samples were extracted with liquid-liquid extraction (LLE) and dispersive solid phase extraction (DSPE), respectively. When liquid-liquid extraction was used, acetonitrile was found to be the best extraction solvent. As for dispersive solid phase extraction, using 1% acetic acid in acetonitrile : acetone = 80:20 as the solvent had the best result. The liquid-liquid extraction method is apt to leave too much impurity to interfere analysis. Dispersive solid phase extraction used solid phase adsorbents to adsorb interference species. Its extraction and purification efficiencies were higher than that of liquid-liquid extraction. Therefore, dispersive solid phase extraction was regarded as the optimum extraction method for descendant experiments. The limits of detection of GA3 and CPPU were 0.4995 and 0.012 μg/g, respectively. The calibration curves for GA3 and CPPU in the range of 0.02 to 5 mg/L showed excellent linearity as their coefficients of determination (R2) were higher than 0.99. The average recoveries of GA3 and CPPU were range from 88.73% to 103.19% and 72.11 to 104.65%, respectively. The contents of GA3 and CPPU in commercially available fruits were also determined. One of ten samples showed a residue of GA3 at the quantity of 0.089 (± 0.002) μg/g, which was less than the allowed maximum residue limits for Taiwan (5 ppm). However, a total of six samples were found to have residual CPPU, range from 0.016 to 0.094 μg/g, which exceeded the maximum residue limits announced by European Food Safety Authority, United States Environmental Protection Agency, Australia Pesticides and Veterinary Medicines Authority, and China.