ECsens, Department of Analytical Chemistry, University of Granada, Granada 18071, Spain.
Unit of Excellence in Chemistry applied to Biomedicine and the Environment of the University of Granada, Spain.
Analyst. 2023 Sep 11;148(18):4533-4538. doi: 10.1039/d3an01056b.
Formaldehyde is a common contaminant in occupational and environmental atmospheres, prolonged exposure leads to health risks, and its determination is necessary to protect health. There is a great demand for portable, rapid, and sensitive methods that can be used in resource-limited settings. In this respect, a colorimetric sensor has been developed based on the colour change from pink to purple of co-immobilized chromotropic acid and 4-aminoazobenzene in hydroxypropyl methylcellulose when it is exposed to different concentrations of formaldehyde. The concentration of formaldehyde in the gas phase was quantified by measuring the change of the appropriate colour coordinates in response to the concentration of formaldehyde. A calibration curve was obtained for formaldehyde, with a useful concentration range from 0.08 to 0.6 ppmv. The detection limit was 0.016 ppmv, which is lower than the maximum exposure concentrations recommended by both the World Health Organization (WHO) and the Occupational Safety and Health Administration (OSHA). The optical sensor was found to have good reproducibility, with a relative standard deviation of 2.3 and 1.7% at 0.08 and 0.25 ppmv, respectively. The sensor can operate at room temperature and environmental humidity, 25 °C, and 50% RH, respectively. In addition, a study of interferents (acetaldehyde, toluene, methanol, ethyl acetate, acetone, acetic acid, carbon dioxide and ammonia) showed high selectivity for formaldehyde, which indicates that this membrane is a simple, fast, and economical alternative for quantifying the concentration of formaldehyde in different environments.
甲醛是职业和环境空气中常见的污染物，长期暴露会导致健康风险，因此需要对其进行测定以保护健康。目前，人们迫切需要能够在资源有限的环境中使用的便携、快速和灵敏的方法。在这方面，我们开发了一种基于变色酸和 4-氨基偶氮苯在羟丙基甲基纤维素中共同固定时，当暴露于不同浓度的甲醛时颜色从粉红色变为紫色的比色传感器。通过测量适当的颜色坐标随甲醛浓度的变化，对气相中甲醛的浓度进行定量。得到了甲醛的校准曲线，其有用的浓度范围为 0.08 至 0.6 ppmv。检测限为 0.016 ppmv，低于世界卫生组织（WHO）和职业安全与健康管理局（OSHA）推荐的最大暴露浓度。该光学传感器具有良好的重现性，在 0.08 和 0.25 ppmv 时，相对标准偏差分别为 2.3%和 1.7%。传感器可以在室温（25°C）和环境湿度（50%RH）下运行。此外，对干扰物（乙醛、甲苯、甲醇、乙酸乙酯、丙酮、乙酸、二氧化碳和氨）的研究表明，该传感器对甲醛具有高选择性，这表明该膜是一种简单、快速且经济的替代方法，可用于定量不同环境中甲醛的浓度。
