AOAC970_45
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ID： |
C2F78D9388A24041A300CAB5C948EE60 |
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文件大小(MB)： |
0.01 |
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页数： |
1 |
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文件格式： |
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日期： |
2013-4-11 |
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购买： |
文本摘录（文本识别可能有误，但文件阅览显示及打印正常，pdf文件可进行文字搜索定位）：
49.2.09,AOAC Official Method 970.45,Aflatoxins in Peanuts,and Peanut Products,BF Method,First Action 1970,Final Action 1988,AOCS–AOAC Method,A. Apparatus,See 970.43A(b), (c), (g)–(i), (k)–(m) (see 49.1.01), and in addition:,Beakers.—Stainless steel, 600 mL.,B. Reagents,See 970.43B(a), (b), (d), (f) (see 49.1.01) and 971.22 (see 49.2.03).,C. Preparation of Sample,See 968.22C (see 49.2.08). Alternatively, prepare peanut samples,by H2O slurry method: Blend 1100 g peanuts comminuted in,subsampling mill with 1500 mL H2O and 22 g NaCl 3 min at medium,speed in 1 gal. blender cup.,D. Extraction,Weigh 100 g prepared peanuts or meal or 50 g peanut butter into,blender jar. Add 250 mL methanol–H2O (55 + 45) and 100 mL hexane,to peanut butter, and 500 mL methanol–H2O (55 + 45), 200 mL,hexane, and ca 4 g NaCl to peanuts or meal. If peanut test portion is,prepared by alternative H2O slurry method, weigh 130 g slurry into,blender jar. Add 50 mL 2.2% salt solution, 150 mL methanol, and,100 mL hexane.,Blend 1 min at high speed. Transfer to 250 mL centrifuge bottle,and centrifuge 5 min at 2000 rpm. (If time is unimportant or centrifuge,is not available, let mixture stand undisturbed in blender jar, as,separation will occur within 30 min for peanut butter and raw or,roasted peanuts.),Pipet 25 mL aqueous methanol phase into 125 or 250 mL separator,add 25 mL CHCl3, stopper, and shake 30–60 s. Let layers separate,and drain bottom CHCl3 layer into 600mLstainless steel beaker,(if available). Do not include any meal with extract. Place beaker on,steam plate under stream of N2 and add small amount of H2O under,beaker to improve heat transfer. (100mLglass beaker is satisfactory,but more time is required for evaporation.) Evaporate solvent to between,2 mL and just dryness or as soon as condensing vapor is no,longer visible on beaker lip. Do not leave beaker on hot plate after,solvent has evaporated. (Alternatively, evaporation may be performed,using Erlenmeyers and steam bath.) Transfer extract with,careful washing, to 4 dram vial and evaporate to dryness under gentle,stream ofN2 in hotH2Obath or in heating block. Dissolve extract,in 200 mL benzene–CH3CN (98 + 2) for spotting on TLC plate.,E. Thin-Layer Chromatography and Calculations,Proceed as in 968.22F (see 49.2.08), except that no correction is,required for fat carried by extracting solvent.,References: JAOAC 53, 104(1970); 57, 871(1974); 66, 355(1983).,. 2000 AOAC INTERNATIONAL……
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