Abstract

A colorimetric method based on digital image processing and an image capture device as a detector has been developed for determining methylene blue (MB) in human and veterinary dosage forms. Operational variables, such as capture devices, angle and modes of capture as well as measuring vessel geometry, were evaluated in order to establish the most suitable conditions to obtain accurate measurements. Three different capture devices including a webcam, a compact digital camera and a smartphone camera were compared. Digital images were analyzed using the open source program ImageJ. Suitable results were achieved when using a 20.7 MP back camera of a smartphone and white-LED lighting conditions. Grayscale values were finally employed as response to determine MB concentration. Satisfactory linearity was achieved in the concentration range from 3.5 × 10^–7 to 4.7 × 10^–6 M, with the determination coefficient R² > 0.97 and the limit of detection of 1.7 × 10^–7 M. The proposed approach was successfully applied to the detection of MB in two commercially available dosage forms for human and veterinary treatment.

中文翻译：

---

通过数字成像确定人和兽药形式中亚甲蓝的简单策略

摘要

已经开发了一种基于数字图像处理的比色法和一种图像检测器作为检测器，用于测定亚甲基蓝（MB）的人和兽用剂型。为了确定最合适的条件以获得准确的测量结果，需要对诸如捕获设备，捕获角度和捕获模式以及测量容器几何形状等操作变量进行评估。比较了三种不同的捕获设备，包括网络摄像头，紧凑型数码相机和智能手机相机。使用开源程序ImageJ分析了数字图像。当使用智能手机的20.7 MP后置摄像头和白光LED照明条件时，可以获得合适的结果。最终将灰度值用作确定MB浓度的响应。在3.5×10 ^–7到4.7×10 ^–6 M的浓度范围内，测定系数R ²达到令人满意的线性> 0.97，检出限为1.7×10 ^–7M。该方法成功应用于人和兽医治疗的两种市售剂型中MB的检测。