Cheng Z, Root M, Pan W, Chen J, Campbell T C
Division of Nutritional Sciences, Comell University, Ithaca, New York 14853, USA.
Cancer Epidemiol Biomarkers Prev. 1997 Jul;6(7):523-9.
An improved monoclonal antibody immunoaffinity chromatography/high-pressure liquid chromatography/ fluorescence detection method was developed to measure aflatoxin (AF) exposure by quantifying AFM1 in human and rat urine samples. Analysis of different amounts of various AF metabolites showed that the immunoaffinity resin was highly selective for aflatoxin B1 (AFB1), AFB2, and AFM1. Recovery of added AFs increased with the amount of immunoaffinity resin and was virtually complete within the range of 0.01-10 ng of AFM1 by using 7 ml of resin. The detection limit of this method is 0.5 pg/ml urine. Rats dosed with tritiated AFB1 excreted in their urine tritiated AFM1, among other AF metabolites, as indicated by chemical derivative confirmation and cochromatography with authentic AFM1 and agreement of radioactivity and fluorescence quantitation. A linear dose-response relationship was found over the range of 0.05-50 micrograms/kg of body weight/day. Two humans dosed with 1.0 microgram of pure AFB1 excreted 6-7% of the dose as urinary AFM1 over 5-7 days. Pooled urine samples from 30 men from each of 69 rural counties in mainland China and 16 survey areas in Taiwan, with two villages per county or area, were analyzed with this improved method (170 villages total). The correlation coefficient of urinary excretion of AFM1 compared between villages within all 85 survey areas was 0.50 (P < 0.001). Sixty-five % of the samples contained detectable concentrations of AFM1 with an average excretion of 3.1 ng/12 h. Assuming an excretion rate of 2-6%, this AFM1 excretion corresponds to a very low average daily AF consumption of 0.1-0.3 microgram/day (possible range, 0-11 micrograms/day). Patterns of urinary excretion of AFM1 were similar in mainland China and Taiwan.
开发了一种改进的单克隆抗体免疫亲和色谱/高压液相色谱/荧光检测方法，通过定量人尿和大鼠尿样中的AFM1来测定黄曲霉毒素（AF）暴露量。对不同量的各种AF代谢物进行分析表明，免疫亲和树脂对黄曲霉毒素B1（AFB1）、AFB2和AFM1具有高度选择性。添加的AFs回收率随免疫亲和树脂量的增加而提高，使用7 ml树脂时，在0.01 - 10 ng AFM1范围内回收率几乎达到100%。该方法的检测限为0.5 pg/ml尿样。用氚标记的AFB1给大鼠给药后，其尿液中排出了氚标记的AFM1以及其他AF代谢物，化学衍生物确认、与标准AFM1共色谱分析以及放射性和荧光定量结果均证实了这一点。在0.05 - 50微克/千克体重/天范围内发现了线性剂量反应关系。两名志愿者摄入1.0微克纯AFB1后，在5 - 7天内，尿中AFM1的排出量占摄入量的6 - 7%。采用这种改进方法对中国大陆69个农村县和台湾16个调查地区（每个县或地区两个村庄，共170个村庄）的30名男性的混合尿样进行了分析。在所有85个调查地区的村庄之间，AFM1尿排泄量的相关系数为0.50（P < 0.001）。65%的样品中AFM1浓度可检测到，平均排泄量为3.1 ng/12 h。假设排泄率为2 - 6%，这种AFM1排泄量对应的平均每日AF摄入量非常低，为0.1 - 0.3微克/天（可能范围为0 - 11微克/天）。中国大陆和台湾的AFM1尿排泄模式相似。
