异丁醇萃取-高效液相色谱法测定马铃薯中α-茄碱

A new method for the extraction and determination of alpha solanine in potatoes

目的建立异丁醇萃取和高效液相色谱法（HPLC）测定马铃薯中α-茄碱含量的新方法。方法马铃薯匀浆样品经5%乙酸溶液搅拌提取30 min,提取液调节p H至11.0后加入异丁醇进行萃取,萃取液加热浓缩,N2吹干。残渣经甲醇复溶,过0.45μm滤膜后进样,HPLC检测α-茄碱含量。流动相为乙腈-0.02 mol/L磷酸二氢钾溶液（22∶78,V/V）,Discovery C18柱（150 mm×4.6 mm,5μm）,柱温30℃,检测波长210 nm,进样量20μl。结果在0.02-1.00 mg/ml范围内,α-茄碱的峰面积和浓度的线性关系良好（r=0.999 7）。检测限和定量限分别为0.68和2.27μg/ml,方法检出限为1.38μg/g。样品在0.04、0.40和2.00 mg/g 3个添加水平下的加标回收率为98%-116%。方法精密度RSD为0.16%-1.79%。结论该方法具有快速、简便,准确度和精密度高等特点,适用于马铃薯中的α-茄碱含量的快速检测。

Objective To develop a new method for rapid determination of alpha solanine in potatoes. Methods The homogenized potato sample was eluted with 5% acetic acid aqueous solution for 30 min,and it was then extracted by isobutanol. The extraction solution was evaporated by nitrogen. Subsequently the residue was redissolved in methanol and analyzed by HPLC after filtration. Separation was obtained by Discovery C18column（ 150 mm × 4. 6 mm,5 μm） and mobile phase of acetonitrile-0. 02 mol / L potassium dihydrogen phosphate（ 22 ∶ 78,V / V） with flow rate of 1. 0 ml / min.The detection wavelength was set at 210 nm and the temperature was 30 ℃. Results Good linearity was obtained for alpha solanine within the range of 0. 02-1. 00 mg / ml,and the r was 0. 999 7. The limit of detection（ S / N = 3） and the limit of quantification（ S / N = 10） were 0. 68 and 2. 27 μg / ml. The average recoveries of different concentration levels were between 98% and 116%. The relative standard deviations（ RSDs） ranged from 0. 16% to 1. 79%. Conclusion This method is fast,simple,precise and it is feasible for the determination of alpha solanine in potatoes.