亲水作用液相色谱脱除人参提取物中农药残留

Hydrophilic interaction liquid chromatography for removal of pesticide residues in ginseng extracts

亲水作用液相色谱法(HILIC)是一种用于改善强极性物质的保留和分离选择性的方法,广泛应用于药物分析、代谢组学、蛋白质组学等领域。该文利用农药分子与皂苷成分在HILIC上的保留行为差异,开发了一种农药残留脱除方法。以市售高纯人参提取物为例,该文评价了农药分子和人参皂苷在亲水色谱柱上的保留行为,并考察了上样量、淋洗体积、上样体积等因素对农残脱除效果的影响。实验结果证明:7种人参皂苷由于糖链上的羟基与亲水色谱固定相上的羧基形成氢键作用而具有较强保留,而农药分子由于亲水性较差且相对分子质量较小,保留很弱,从而一步实现了7种人参皂苷的富集与14种农残的脱除。在优化所得的最佳脱除工艺条件下,最终制备得到的人参总皂苷样品中,总皂苷的含量由59.87%提高到69.61%;总皂苷的回收率为94.4%;通过气相色谱-三重四极杆质谱(GC-MS/MS)对样品中的农残进行定量检测,发现原人参提取物中14种农残均得到了有效脱除,其中5种含量降至0.05 mg/kg以下,9种完全脱除。本研究是亲水色谱在中药提取物中农残脱除领域的应用,为天然产物的精制提供了一种新的技术手段,该技术对人参提取物中的农残脱除率高、人参总皂苷回收率高且安全、高效、无污染,为高品质人参提取物的研制提供了新的思路。

Ginseng extracts are rich in a variety of ginseng monomer saponins,which have pharmacological functions of retarding aging,enhancing immunity,stimulating blood circulation,and lowering blood pressure.Ginseng is widely used in health products and dietary supplements in the domestic and foreign market.However,the amount of pesticide residues is an important index for measuring the quality of ginseng and ginseng extracts.Therefore,studies focused on methods for the removal of pesticide residues in ginseng extract are of great significance.Hydrophilic interaction liquid chromatography(HILIC)is used to improve the retention and separation selectivity of strongly polar substances,and it is widely employed in drug analysis,metabolomics,proteomics,etc.In this study,a method for the removal of pesticide residues was developed based on the difference in the retention behavior of pesticide residues and ginsenosides on the HILIC column.Using commercially available ginsenoside extracts,the retention behaviors of pesticide residues and ginsenosides on reverse chromatography and hydrophilic chromatographic columns were evaluated by high performance liquid chromatography.The results proved that on the reversed-phase liquid chromatography(RPLC)stationary phase,in addition to the strong retentions of quintozene and pentachloroaniline,which could be clearly separated from the saponins,the retentions of the other five pesticide residues including carbendazim,azoxystrobin,procymidone,iprodione and propiconazole were similar to total ginsenosides.The seven ginsenosides showed strong retention due to the formation of hydrogen bonds between the hydroxyl groups on the sugar chain and the carboxyl groups on the HILIC stationary phase.However,the pesticide residues were not well retained because of their poor hydrophilicity and small molecular weights.For this reason,the pesticide residues and ginsenosides could be completely separated on the HILIC column.Thus,enrichment of the seven ginsenosides and removal of the 14 pesticide residues was realized in one step on the HILIC column.In addition,the effects of loading amount,loading volume,and washing volume on the removal of pesticide residues in ginsenosides were investigated using the Click XIon SPE column.Then,taking the ginsenoside recoveries and pesticide residue removal rates into account,we confirmed the following:the ratio of the maximum sample loading mass to the filler mass was 1∶10;the optimal elution volume was twice the column volume;and the optimal loading volume was twice the column volume.The ginseng extracts were solvated with a 95%ethanol solution and loaded onto an HILIC column.The sample was subjected to pesticide residue removal,and ginsenoside purification and enrichment under the optimum removal conditions.Gradient elution was carried out using ethanol and water as the mobile phases.The total ginsenoside content in the final extracts was increased to 69.61%.The recovery of the total ginsenosides was 94.4%.The pesticide residues in the samples were quantitatively detected by gas chromatography-triple quadrupole mass spectrometry(GC-MS/MS)in the multiple reaction monitoring(MRM)mode.The 14 pesticide residues in the original ginsenoside extracts were effectively removed.The amounts of five residues were reduced to below 0.05 mg/kg,while the other nine residues were completely eliminated.This study demonstrates the application of HILIC to pesticide residue removal in traditional Chinese medicine extracts and reveals a new technique for the purification of natural products.The proposed method shows a high removal rate of pesticide residues and a high recovery of total ginsenosides.It is safe,efficient,and environment-friendly,and can aid the development of high-quality ginsenoside extracts.