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Abstract: Licorice is widely used as additives in food and pharmaceutical industries and Glycyrrhiza uralensis is one of the main sources of licorice in China. G. uralensis may be contaminated by mycotoxins during growth, collection, transportation and, especially, storage. A rapid and highly sensitive method was firstly developed to determine aflatoxins (AFs) and ochratoxin A (OTA) in G. uralensis using high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). Due to the complexity and high color of the investigated matrices, the proposed method is based on sonication extraction using a methanol/water mixture (80:20, v/v) followed by immunoaffinity column (IAC) cleanup. The limits of quantification (LOQs) of aflatoxins B1, B2, G1, G2 and OTA were 0.020, 0.015, 0.010, 0.015 and 0.010 μg/kg based on a signal-to-noise ratio of 10: 1, respectively. Good linearity was observed for all the analytes of interest, with correlation coefficients all higher than 0.995 within their respective linear ranges. Among the total of 15 G. uralensis samples collected from different areas in China, 6 were moldy due to inappropriate storage and 9 were fine without any visible mold contamination. The results showed that almost all the samples were contaminated with AFs and OTA. The AFs and OTA levels found in the moldy samples were higher than those not visibly moldy and two of the moldy samples exceeded the maximum limit set for OTA in licorice by EU regulation. This is the first report of the co-occurrence of AFs and OTA in G. uralensis in China. [Copyright &y& Elsevier]

A simple and sensitive HPLC coupled with photodiode array ( HPLC-PDA) method was developed for simultaneous determination of seven lignans in Justicia procumbens using relative response factors ( RRFs). The chromatographic separation was performed on a Shiseido Capcell Pak C18 column (250 × 4.6 mm id, 5 μm), a gradient elution of acetonitrile/water, and a photodiode array detector. The column temperature was maintained at 35° C and the detection wavelength was set at 256 nm. Chinensinaphthol methyl ether was selected as the reference compound for calculating the relative response factors of the lignans. It has shown that the RRFs for lignans are quite similar at 256 nm of detection under different analytical conditions (different columns and HPLC instruments). Using RRFs, not every lignan is needed as a reference standard, making the method ideal for rapid, routine analysis, especially for those laboratories where lignans standards are not readily available. An economic and practicable HPLC method using RRFs was established for the determination of seven lignans in J. procumbens. This method not only can determine multiple indexes in traditional Chinese medicines (TCMs) simultaneously, but also resolve the problem of lacking of chemical standards. It will be a good quality evaluation method and pattern for TCMs. [ABSTRACT FROM AUTHOR]

Objective: To develop a method for the simultaneous determination of aflatoxin B1, B2, G1, G2 and ochratoxin A in Glycyrrhiza uralensis by HPLC-FLD after immunoaffinity column with online post-column photochemical derivatization., Method: Sample was extracted with MeOH: H2O (80:20) and cleaned up by immunoaffinity column. The toxins were separated by reversed-phase HPLC and the mobile phase was consisted of methanol and 0.5% acetic acid solution with gradient elution. The determination was carried out by fluorescence detector after photochemical derivatization., Result: The detection limits of aflatoxin G2, G1, B2, B1 and ochratoxin A were 0.02, 0.06, 0.015, 0.03 and 0.25 microg x kg(-1), respectively. The recoveries of analytes were from 76.0% to 103% and the relative standard deviations (RSDs) were below 13%., Conclusion: The method is a simple, accurate and can be used to determine the contents of aflatoxin B1, B2, G1, G2 and ochratoxin A in G. uralensis simultaneously.