Quantification of Some Herbal Distillates’ Methanol to Evaluate a New Diagnostic Kit

Abstract

Methanol naturally exists in all plant products. In recent years, the consumption of certain kinds of herbal distillates has led to blurred vision, leading to neurotic blindness in Iran. The advanced methods needed for determination of methanol are not available in all parts of poor and developing countries. In this study, we evaluated some herbal distillates’ methanol with a new kit compared to gas chromatography for determining the efficacy of the kit. A gas chromatography apparatus was used to determine methanol concentration of 57 herbal distillates. At the same time, a spectrophotometer device was also used along with a newly designed kit based on the modified chromotropic acid method for the same purpose. All examined samples have different amounts of methanol from 21 to 770 mg/l. The methanol content of all samples was higher than the used kit’s limit of quantification (5 mg/l). The attained results by two used methods were very close together in both minimum (21 and 22 mg/l) and maximum (770 and 690 mg/l) amounts. The comparison of results was shown, and some of available herbal distillates in Iran have enough amounts of methanol to create chronic type of methanol poisoning. Our results suggested that the used kit had suitable efficacy for quantitative determination of herbal distillates’ methanol content. It was proved that the type of the herbal distillate did not affect the kit’s function. The new kit can be easily used with minimal equipment for quality control of herbal distillates in food industry area.