Maqbool Uzma, Mahboob Sadia
Nuclear Institute for Agriculture and Biology, P.O. Box 128, Faisalabad, Pakistan.
J AOAC Int. 2010 Jan-Feb;93(1):19-27.
A dipstick format was developed for on-site atrazine monitoring in water samples of different origins. It was derived from an in-house-developed ELISA based on polyclonal antibodies that also cross-react with hydroxyatrazine (30%) and terbuthylazine (17%). Test reagents were evaluated for temperature and pH stabilities and rapidity for field applications. Reagents performed well within a temperature range of 20-30 degrees C and were tolerant to alkaline pH (up to 8.5) of the assay buffering system. Tracer incubation time could be reduced to 40 min. Bovine serum albumin addition (1%) in the assay buffer improved assay performance, giving 50% B/B0 (IC50) of 65 ng/L and the lowest LOD of 2 ng/L at 90% B/B0 (IC10). The dipstick ELISA format was standardized on a membrane support. Nylon membrane, positively charged, was superior to PVDF for qualitative or semiquantitative analysis regarding color intensity and stability. Tracer incubation time was further reduced to 30 min with a lowest LOD of 0.1 microg/L. For real sample screening with dipsticks, acceptable results were obtained for water. Significant correlation was found between dipstick and plate ELISA results. Validation using GC with a nitrogen-phosphorus detector and HPLC indicated that dipstick signals in aged water samples, which were mainly due to hydroxyatrazine, were significantly above European Commission regulations of 0.1 microg/L. However, dipsticks were superior, fast, and cost-effective.
开发了一种试纸条形式用于现场监测不同来源水样中的阿特拉津。它源自基于多克隆抗体的内部开发的酶联免疫吸附测定法（ELISA），该抗体也与羟基阿特拉津（30%）和特丁津（17%）发生交叉反应。对测试试剂进行了温度、pH稳定性以及现场应用快速性的评估。试剂在20 - 30摄氏度的温度范围内表现良好，并且能耐受测定缓冲系统的碱性pH（高达8.5）。示踪剂孵育时间可缩短至40分钟。在测定缓冲液中添加1%的牛血清白蛋白可提高测定性能，在90% B/B0（IC10）时，50% B/B0（IC50）为65 ng/L，最低检测限为2 ng/L。试纸条ELISA形式在膜载体上进行了标准化。带正电荷的尼龙膜在颜色强度和稳定性方面优于聚偏二氟乙烯（PVDF）用于定性或半定量分析。示踪剂孵育时间进一步缩短至30分钟，最低检测限为0.1 μg/L。对于用水样进行的试纸条实际样品筛查，获得了可接受的结果。发现试纸条和酶标板ELISA结果之间存在显著相关性。使用带氮磷检测器的气相色谱法（GC）和高效液相色谱法（HPLC）进行的验证表明，老化水样中的试纸条信号主要归因于羟基阿特拉津，显著高于欧盟委员会规定的0.1 μg/L。然而，试纸条具有优势，快速且成本效益高。
