纸基芯片法快速检测自来水和食品中的铁含量

Rapid detection of iron content in tap water and food by paper-based microfluidic chip

中文关键词:  纸基芯片  Fe₃₊  灰度值  可视化检测

英文关键词:paper based microfluidic chip  Fe3+  gray value  visual detection

中文摘要:

      目的 建立纸基芯片快速检测自来水和食品中铁含量的方法。方法 使用压花器裁剪出纸基芯片的形状, 通过浸泡的方式制备芯片。使用时直接向制备好的芯片滴加试样, 基于邻二氮菲显色法显色后将芯片置于实验室自制平台拍照, 读取照片灰度值完成铁的检测。研究筛选了滤纸种类, 优化了芯片制备1,10-菲啰啉和盐酸羟胺的浓度、浸泡时间及显色时间。结果 选用Whatman 3#滤纸, 在含有8.00 g/L的1,10-菲啰啉, 50.00 g/L盐酸羟胺的醋酸盐缓冲液(pH=4.50)中浸泡3 min, 加样后显色15 min即可拍照检测。Fe3+浓度为5.00×10–3~7.00 mmol/L时, 灰度值与浓度呈良好的线性关系; 检出限为0.004 mmol/L; 试样中共存1 mg/L的Cd2+、Cu2+等13种金属离子时, 不影响铁的检测; 方法加标回收率为86.0%~114.7%; 同1 d内连续测定6次相对标准偏差为1.7%~7.5%, 连续6 d测定相对标准偏差为3.4%~7.9%, 制备好的纸基芯片在4 ℃避光条件下至少可保存3个月。方法对实际样品检测的结果与火焰原子吸收检测结果相对偏差小于等于2.404%。结论 所建立的铁含量纸基芯片检测方法操作简便、准确可靠, 能够为食品领域铁含量的现场快速检测提供一定参考。

英文摘要:

      Objective To establish a method for rapid detection of iron content in tap water and food samples by paper-based microfluidic chip. Methods The paper-based chips were cut out using an embossing gadget. And the paper chip was prepared by soaking. Samples to be tested could be dropped onto the prepared chips directly. When the chip showed a stable color based on O-dinitrogen colorimetric method, the chip could be placed on a self-made platform for taking photo. Then the gray value of the picture could be read and the iron concentration could be acquired. The study selected the type of filter paper, and optimized the concentrations of 1,10-phenanthroline and hydroxylamine hydrochloride during soaking, as well as the soaking time and coloring time. Results Whatman 3# filter paper was selected to prepare the paper chip. And the cut paper chip was soaked in acetate buffer solution containing 8.00 g/L of 1,10-phenoroline and 50.00 g/L of hydroxylamine hydrochloride (pH=4.50) for 3 minutes. After the sample was dropped onto the paper chip for 15 minutes, photos could be taken for detection. When the concentration of Fe3+ in sample solution was 5.00×10–3 mmol/L to 7.00 mmol/L, it had a good linear relationship between the gray value and the concentration. The limit of detection the paper chip method was 0.004 mmol/L. When the 13 kinds of interfering metal ions, including 1 mg/L Cd2+, Cu2+ and the like, were coexisting in the sample solution, they did not affect the detection of Fe3+. The adding standard recoveries were 86.0% to 114.7%. The relative standard deviations of the same sample 6 test results within the same day were 1.7% to 7.5%. And the relative standard deviations of 6 consecutive days detection results were 3.4% to 7.9%. The prepared paper chip could be stored for at least for 3 months under the condition of avoiding light at 4 ℃. When the actual samples were detected, the relative deviation between the paper chip method and the flame atomic absorption method was less than or equal to 2.404%. Conclusion The iron detection method based on paper-based chips established in this research is simple to operate, accurate and reliable, which can be a strong support for on-site rapid detection of iron content in food detection field.