Advancement of colloidal gold chromatographic technique in screening of ochratoxin A / 中国中药杂志

Ochratoxin A (OTA) is a toxic secondary metabolite mainly produced by Aspergillus and Penicillium species, existing in a variety of foodstuffs and Chinese medicines. OTA is difficult to be detected in practice because of the characteristics such as trace amounts, toxicity, existing in complex matrices. In the numerous detection technologies, colloidal gold chromatographic techniques are highly sensitive, specific, cost-effective and user-friendly, and are being used increasingly for OTA screening. Recently, with the development of aptamer technology and its application in chromatographic technique, a newly colloidal gold aptamer chromatographic technique has been developed. This review elaborates the structures and principles of both traditional and newly colloidal gold chromatographic techniques, focuses on newly colloidal gold aptamer chromatographic technique, summarizes and compares their use in rapid detection of OTA. Finally, in order to provide a reference for better research of related work, the development trends of this novel technique are prospected.

Dynamic analysis of alkaloids and flavonoids in Genus Morus L. in China during different harvesting time / 中国中药杂志

To investigate the optimum harvesting time and utilization of mulberry leaves during different growth periods based on the content of alkaloids and flavonoids, 88 samples of 11 species of mulberry leaves were collected and analyzed. UPLC-TQ/MS method was applied and the results showed that the ingredients of alkaloids and flavonoids in mulberry leaves are quite different in different growth periods and different species. There was a sharp decline of the average content of alkaloids in all samples from October, while the content of flavonoids dropped either from October but with less volatile. The content of flavonoids in M. atropurpurea was much higher than alkaloids, while M. australis was opposite completely. There was a sharp decline of alkaloids in M. cathayana and M. mongolica from Tuly to August, however, the content of alkaloids and flavonoids in M. alba is neither too high nor too low. In summary, it is more suitable to harvest tender mulberry leaves harvested from the end of September to beginning of October that provide a scientific evidence for rational harvest and comprehensive utilization of mulberry leaves.

Determination of ochratoxin A in human urine by HPLC-FLD after cleaned-up by molecularly imprinted polymer solid phase extraction column / 药学学报

A method was developed for the determination of ochratoxin A (OTA) in human urine by HPLC-FLD after molecularly imprinted polymer solid phase extraction (MIP-SPE) column. After the pH being adjusted to 2.5 with 0.1 mol x L(-1) HC1, sample was cleaned up with MIP-SPE column for ochratoxin A, the analyte was analyzed by high performance liquid chromatography coupled with fluorescence detection (HPLC-FLD), and finally all the positive results were confirmed by LC-MS/MS. Recoveries from urine samples spiked with OTA at levels ranging from 2 to 20 ng x mL(-1) were 90.6%-101.9%, and RSDs were 0.1%-1.6%. Sixty-five volunteers living in Beijing took part in the study, of which 5 were found containing OTA in their urine and the highest value was 0.091 ng x mL(-1). The MIP-SPE column was firstly applied to purify and concentrate OTA in human urine, this method is simple, rapid and reliable and can be used to determine the contents of OTA in human urine.