Determination of Methanol Content in Herbal Distillates Produced in Urmia Using Spectrophotometry

Herbal distillates have been used for many centuries as drinks, flavors, and herbal medicine in Iran, especially in the city of Urmia. Recently, some studies claimed the presence of methanol in different types of herbal distillates. Methanol is a highly toxic compound which can cause acute or chronic toxicity in humans. Acute poisoning with methanol can cause different complications and even death while chronic methanol exposure has a wide range of nonspecific and misleading findings. The main purpose of this study was to determine methanol content in the commonly-used industrial herbal distillates produced in Urmia. Five samples of six types of most commonly used herbal distillates (peppermint, musk willow, lemon balm, pennyroyal, dill, and rose water) were purchased from five active herbal distillates manufacturers in Urmia. All samples were transferred to the laboratory and methanol content of each sample was measured two times according to the standard method of analysis using spectrophotometer. The lowest and highest concentration of methanol were found in rose water (mean=72.4±32.1 ppm) and musk willow (mean=278.3±106 ppm) samples, respectively. One-way ANOVA showed statistically significant differences among methanol concentrations in the studied herbal distillates (F=60.9, P <0.001). Different amounts of methanol were found in herbal distillates and it seems that there are statistically significant differences in methanol concentrations of various types of herbal distillates. Therefore, considering the harmful effects of methanol on human health, further studies are required for determining permitted levels of methanol in herbal distillates.