| Mycotoxin is the toxic metabolite or the secondary metabolic produced by certain fungus, Generally existing in the moldy crops. It covers a wide distribution and is of great hazard. Once entering an animal’s body, mycotoxin may causes serious danger, such as deformity, mutation and cancer and so on. Futhermore it will also affect livestock’s production, which then leads to the decline in the quality of human life. With extensive pollution and high toxicity, ZEN, T-2and FB1are more serious of all. Therefore it is crucial to study on the method of detection about fungal toxins.ZEN toxin mainly affects the reproductive function of animals. T-2toxin, belongings to trichothecenes mycotoxins. T-2toxin is of enterotoxigenic and hepatotoxicity. Fumonisin(FB1) is full of neurotoxicity, pulmonary toxicity, immunotoxicity, carcinogenicity, embryotoxicity, phytotoxicity and some other toxic effects.Test I Optimization of HPLC for ZENThe method has been established and improved for quantitative detection of ZEN toxin in feedstuffs with HPLC. The clean-up procedure for extracts is immunoaffinity columns. Feedstuff samples are extracted with acetonitrile+water=75+25(v+v). Analysis is carried out by using a mobile phase composed of methylalcohol+acetonitrile+water=10+46+44(v+v+v), with a flow speed of0.6mL·min-1, a column temperature of25℃and fluorescence detection (Ex274nm, Em440nm). The detection limit is5.7μg·kg-1, and the limit of quantitation is19μg·kg-1. It is showed that a good linear relationship at a ranger of0.025～0.8μg·mL-1. The linear equation is y=629600χ+127.49, R2=0.9997. The coefficient of recovery is up to91.3%, and the relative standard deviation is generally lower than3.10%.Test Ⅱ Optimization of HPLC for T-2The method has been established and improved for quantitative detection of T-2toxin in feedstuffs with HPLC and2-naphtoyl chloride (2-NC) as ladeling reagent and4-Dimethylamino pyridine as reaction accelerator. Feedstuff samples are extracted with methylalcohol+water=90+10(v+v). Analysis is carried out by using a mobile phase composed of acetonitrile+water=75+25(v+v), with a flow speed of0.6mL·min-1, a column temperature of30℃and fluorescence detection (Ex381nm, Em440nm). The detection limit is1.8μg·kg-1, and the limit of quantitation is6μg·kg-1. It is revealed that a good linear relationship at a range of0.025-0.8μg·mL-1. The linear equation is y=2186.2χ-31953, R2=0.9992. The coefficient of recovery reaches91.92%, relative standard deviation is generally lower than3.13%.Test Ⅲ Optimization of HPLC for FB1The method has been established and improved for quantitative detection of FB1toxin in feedstuffs with HPLC and O-phthalaldehyde(OPA) as ladeling reagent. Feedstuff samples are extracted with acetonitrile+water+methylalcohol=25+25+50(v+v+v). Analysis is carried out by using a mobile phase composed of methylalcohol+0.1mol·L-1(pH3.3)=77+23(v+v), with a flow speed of0.6mL·min-1, a column temperature of30℃and fluorescence detection (Ex333nm, Em440nm). The detection limit is2.16μg-kg-1, and the limit of quantitation is7.2μg·kg-1. It is presented that a good linear relationship at a range of25-1000ng·mL-1. The linear equation is y=20257χ-104237, R2=0.9996. The coefficient of recovery is90.91%, relative standard deviation is generally lower than2.86%.Test IV Pollution situation of ZEN, T-2, FB1in feed samplesTest for detection of the content of ZEN, T-2, FB1is from17provinces, with a total of270copies of feed raw materials and300copies of nutritional feed. The results showed that the detection rates of ZEN, T-2and FB1are at a relatively high level. FB1is polluted seriously whose over-standard rate is the highest. Moreover, the over-standard rate of T-2is lower. |
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