高效液相色谱法测定甘薯中β-胡萝卜素

Determination of β-carotene in sweet potato by high performance liquid chromatography

目的：建立甘薯中β-胡萝卜素的高效液相色谱测定方法。方法：以丙酮-石油醚（20：80）混合液研磨提取样品中的β-胡萝卜素，经无水硫酸钠脱水后，旋转真空蒸发除去大部分溶剂，用弱氮气流吹干，然后用丙酮-石油醚（5：95）混合液定容至2ml，取适量进行高效液相色谱分析。色谱条件：色谱柱为Agilent Lichrosorb RP-18（4．6mm×200mm，5μm）；流动相为乙腈-甲醇-乙酸乙酯-三乙胺（80：10：10：0．05）；检测波长为450nm。结果：该法线性范围为0．4—2500ng，检出限为0．4ng，相对标准偏差为4．0％，回收率为85．5％-89．5％。所测不同产地的14个不同品种甘薯样品中β-胡萝卜素含量范围为0．59—231．1mg／kg。结论：本法简便、快速、准确、灵敏，适用于甘薯中微量β-胡萝卜素含量的测定。

Objective：To establish a method for the determination of β - carotene in sweet potato by reversed - phase high performance liquid chromatography. Methods： β- carotene in sweet potato was extracted with acetone- petroleum ether（20：80）, then let the extract pass through a funnel containing anhydrous sodium sulfate to remove water,finally the extract was concentrated in a rotary vacuum evaporator. Before analysis, remove the solvent under N2, and redissolve in acetone -petroleum ether（5：95 ）. Chromatographic conditions： using Agilent lichrosorb RP - 18 （4.6 mm× 200mm,5 μm） as chromatographic column ; acetonitrile ： methanol ： ethyl acetate ： triethylamine （80 ： 10 ： 10：0. 05） as mobile phase, flowrate 2 ml/min, column temperature 20℃ ; β - carotene was detected at 450 nm. Results：The method was proved to be linear in the range of 0. 4 - 2 500 ng. The determination limit was 0.4 ng（S/N =3）. The RSDs was 4.0%. The recovery was 85.5% - 89.5%. The content range of β - carotene in 14 different breed of sweetpotato samples was 0. 59 - 231 mg/kg. Conclusion：The method is simple, fast, accurate and precise. It is suitable for determining β - carotene in sweet potato with satisfactory results.