Detection of synthetic food color

To establish a rapid method for determining of acid yellow 36 in moxibustion. Based on the principle of acid yellow 36 as an acid-base indicator and discoloration in the pH range of 1.2(red) to 2.3(yellow), 15% sulfuric acid solution was used as the color developing agent to screen the ethanol extract of the sample, and then HPLC method was used to verify the suspicious positive samples in the initial screening, and finally LC-MS method was used to confirm the accuracy of the established rapid physicochemical detection method. The established method was applied to 67 batches of samples, and 3 positive samples were detected. The results were consistent with those of HPLC and LC-MS. The method is accurate and sensitive, which can be used for rapid detection of acid yellow 36 in moxibustion.