House Food Analytical Laboratory Inc, 1-4 Takanodai, Yotsukaido, Chiba 284-0033, Japan.
J Agric Food Chem. 2010 Feb 10;58(3):1416-9. doi: 10.1021/jf9032798.
Iprodione is an agricultural fungicide that is difficult to detect in foods by HPLC because it coelutes with natural compounds in the food. We previously showed that food matrix could be degraded with titanium dioxide powder (TP). Here we describe an improved method for detection of iprodione using silica gel supported titanium dioxide (SGT). To synthesize SGT, titania-sol was mixed with diethanolamine, 2-propanol, and titanium tetraisopropoxide. After titania-sol was infiltrated into the silica gel (particle diameter 4 mm), the mixture was dried and then heated. Crude basil extract containing iprodione was mixed with SGT in a quartz vial, and the vial was irradiated with a UV light to selectively decompose the matrix interfering with the iprodione determination. In HPLC chromatograms of the treated solution, the interference peak decreased 35 times faster with SGT than with TP. When SGT (11 g) was added to the extract (20 mL) of dry basil (2 g), black light irradiation for 30 min was enough to quantify iprodione. The recovery rate of iprodione was 99.1%. Thus, the photocatalytic cleanup method using SGT is effective for analyzing residual iprodione in dry basil.
异丙定是一种农用杀真菌剂，由于其与食物中的天然化合物共洗脱，因此很难用高效液相色谱法（HPLC）检测到。我们之前曾表明，食物基质可以用二氧化钛粉末（TP）降解。在这里，我们描述了一种使用硅胶负载的二氧化钛（SGT）检测异丙定的改良方法。为了合成 SGT，将二氧化钛溶胶与二乙醇胺、2-丙醇和钛四异丙醇盐混合。将二氧化钛溶胶渗透到硅胶（粒径 4 毫米）中后，将混合物干燥并加热。含有异丙定的粗罗勒提取物与 SGT 在石英小瓶中混合，并用紫外光照射，以选择性地分解干扰异丙定测定的基质。在处理后的溶液的 HPLC 色谱图中，与 TP 相比，SGT 使干扰峰的减少速度快 35 倍。当将 SGT（11 克）添加到 2 克干罗勒（2 克）的提取物（20 毫升）中时，用黑光照射 30 分钟足以定量测定异丙定。异丙定的回收率为 99.1％。因此，使用 SGT 的光催化净化方法可有效分析干罗勒中的残留异丙定。
