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OBJECTIVE: To establish a method for the quality control of cattle bile powder based on cholic acid components, evaluate the quality of commercially sold cattle bile powder, and analyze the possible adulteration. METHODS: A method was established for simultaneous determination of cholic acid content in bile powder of cattle, sheep, pig, chicken, duck and other animals. Self-made samples and samples collected by enterprises were studied respectively. Based on self-made samples, the differences and content rules of bile powder of cattle, pig, sheep and other animals were investigated, and the quality and possible adulteration of samples collected by enterprises were evaluated. RESULTS: An HPLC-ELSD method was established for simultaneous determination of 12 cholic acids in bile powder of cattle, sheep, pigs, chickens and ducks. By analyzing the determination results of 23 batches of self-made animal bile powder, the contents of cholic acid in cattle bile powder and other animal bile powder were determined. By analyzing the determination results of cattle bile powder samples collected from 23 enterprises, it was found that there were mainly two kinds of adulteration of cattle bile powder likely: sheep bile powder and cholic acid waste. Only 8 of the 23 batches of samples collected by enterprises met the requirements, and the qualified rate was only 34.8%. The quality of varieties needs to be improved and supervised urgently. CONCLUSION: The method established in this study can effectively control the quality of cattle bile powder, identify possible adulteration of cattle bile powder, and provide reference and basis for improving the quality standard of cattle bile powder and strengthening market supervision.
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Tea is one of the most popular drinks in the world, but counterfeit or adulterated tea can be found now and then on the tea market. The traditional methods dependent on sensory, physical and chemical tests cannot identify the composition of adulterated plant species accurately. We developed therefore a method for identification of adulterated plants in tea based on qualitative detection of plant rbcL (Ribulose 1,5-bisphosphate carboxylase-oxygenase large subunit) fragments, which involved amplification, sequencing and sequence analyses of rbcL fragments. Seven tea samples were analyzed with the established method. The results showed that Yueyanghuangcha (yellow tea) and Xinyangmaojian (green tea) were pure with only detection of the tea plant Camellia sinensis; Zhengshan Souzhong (black tea), Tieguanyin (oolong tea), Tailaoyinzhen (white tea), Liupao and Pu-erh (dark tea) were, to a certain extent, adulterated with non-Camellia sinensis plants. The method introduced in this study only requires a small amount of tea samples, easy to operate and reliable. It can be used to determine if any tea samples are adulterated.
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A rapid method for authenticity detection of grapeseed oil was proposed based on Ion Mobility Spectrometry ( IMS) . After optimization, the inlet temperature was set at 170 ℃, drift tube temperature was set at 60 ℃. In this method, the oil sample was diluted in hexane (50-fold, V/V) and then directly analyzed in IMS. The detection time was 20 s. To establish an adulteration detection model, recursive Support Vector Machine ( R-SVM) was applied to classifying pure and adulterated grape seed oils. The result of 10-fold cross validation showed that the accuracy of discrimination was up to 91 . 2%. The results in study indicate that IMS method is a new, fast and convenient technique for the adulteration detection of edible oil.