Studies on CALUX bioassay for dioxins in milk products

• Main Authors: Cheng-Ming Chu, 朱正明
• Other Authors: Deng-Fwu Hwang
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/44071025047666955464

碩士 === 國立臺灣海洋大學 === 食品科學系 === 94 === Abstract Dioxin pollution problems have been concerned in recent years. Because the traditional measurements of dioxin are always precise and expensive and take a long time, they are difficult to develop the extensive investigation and match time efficiency. Nowadays, a fast bioassay technology for dioxin measurement in Europe has been created. The cell's detection method of CALUX bioassay which amount of dioxin can be calculated with the cold luminous intensity and TCDD toxicity. The limit of detection (LOD) was 0.27 pM 2,3,7,8-TCDD, and limit of quantitation (LOQ) was 0.92 pM 2,3,7,8-TCDD. It showed good recovery (90±10%) and low coefficient of variation (≦13.8%) on the CALUX bioassay measurement. For this fast bioassay method, the standard curve had excellent linear relation and the coefficient correlation was more than 0.999. The method was more repeatable and stable because the coefficient of variation for intra- and inter-day analysis was smaller than 4.0% and 9.5%, respectively. Comparison with the fast bioassay method (CALUX bioassay) and the traditional analytical method (HRGCMS), the total toxic equivalent of dioxin was 0.23 and 2.28 pg/g fat for the milk power and fresh milk, respectively, with the traditional analytical method, and 0.86 and 2.76 pg/g fat for the milk power and fresh milk, respectively, with the fast bioassay method. The total toxic equivalent of dioxin was 1.67 and 2.20 pg/g fat for traditional analytical method and fast bioassay method, respectively, in whole ox's dairy products. The data from both methods present straight dependence (r =0.85). The dioxin average content was between 0.18-4.20 pg/g fat and the total average was 1.77 ± 0.90 pg/g fat by analyzing 56 samples of the whole ox's dairy products which include fresh milk, milk power and other dairy products. To compare to the limit of the dioxin total toxic equivalent (less than 3 pg/g fat) of Taiwan and international organization, 4 out of 52 fresh milk samples containing 3.06, 3.68, 4.16 and 4.20 pg/g fat were more than the limit. These samples were further analyzed by a confirmatory method of HRGCMS and showed 1.58, 2.89, 2.69 and 0.98 pg/g fat. These data were all lower than the limit of the European legislation. Although this technology is unable to offer the concentration of 29 kinds of specific dioxin compounds, it can apply the fast method to screen the milk products because the relationship between the cell toxicity test and traditional analytical method is good. For selecting dioxin containing samples, the fast bioassay method is useful in the beginning of measurement. If the values of the samples determined by fast bioassay method were in excess of the standard limit, those samples will be further determined by traditional analysis. Therefore, the fast bioassay method is rapid and valid for preventing the invasion of dioxin containing sample. Keyword: Dioxin, Toxicity equivalency quantity (TEQ), DR CALUX® bioassay (Dioxin Response-Chemically Activated LUciferase eXpression bioassay), HRGCMS （High resolution gas chromatography/mass spectrometer）