反相高效液相色谱法测定褐藻中岩藻黄素的含量

摘要

建立一种反相高效液相色谱法用于海藻中岩藻黄素的定量分析,并测定新鲜及干制褐藻中岩藻黄素含量,探究不同干制方式对褐藻岩藻黄素的影响.样品经甲醇提取、C18柱固相萃取净化后,采用ZORBAX SB-C 18色谱柱,流动相采用水与甲醇梯度洗脱,流速0.7 ml/min、进样量10 μ1、柱温35℃、检测波长450 nm进行液相色谱分析.在该条件下,岩藻黄素在0.11～50 mg/L范围内有良好的线性关系(Y=38.46X+0.8899,R2=0.9999),检测限为0.03 mg/L,回收率为92.66％～109.06％,相对标准偏差(RSD)为3.46～4.61％.采用该方法,岩藻黄素提取净化完全,杂质干扰小,回收率高,能够对海藻及其制品中岩藻黄素进行准确定量.采用该方法测得新鲜海带和马尾藻的岩藻黄素含量(干基)分别为559.2和680.4 mg/kg,而干制褐藻样品中岩藻黄素的含量明显低于新鲜褐藻.不同干制方式造成的岩藻黄素损失程度为真空冷冻干燥＜45℃烘干≈自然晾干.因此,在规模化分离制备海藻岩藻黄素时,宜采用新鲜或冻干海藻作为原料,从而保证岩藻黄素的得率.%To investigate the influences of different drying methods on the levels of fucoxanthin,a new RP-HPLC method was established to determine the fucoxanthin content in the fresh or dried kelp and sargassum samples.The samples were extracted by methanol and then treated by C 18 column solid-phase extraction to remove the other liposoluble components.The separation column was ZORBAX SB-C18(4.6× 150 mm,5 μm),which was held at 35 ℃.The mobile phase was composed of the gradient changes of methanol and ultrapure water at a flow rate of 0.7 ml/min.The sample loading volume was 10 μl.UV detection was performed at 450 nm.The method showed a good linear relationship between peak area and concentration over the range from 0.11 to 50 mg/L (R2=0.9999).The recoveries of fucoxanthin in three replicates ranged from 92.66％ to 109.06％.The limit of detection was 0.03 mg/L.The RSD of precision was 3.46％ to 4.61％.This method is simple,high sensitive and accurate.The levels of fucoxanthin in the fresh kelp and sargassum samples were 559.2 mg/kg (dry weight) and 680.4 mg/kg (dry weight),respectively.The fucoxanthin levels of the dried brown seaweed samples were significantly lower than those of fresh samples.All drying methods destroyed fucoxanthin in the seaweed samples,while freeze drying method was found superior to the low-temperature drying (45 ℃) method and natural drying method.Therefore,the fresh and freeze-drying seaweeds should be ensured to achieve high yield during the large-scale preparation of fucoxanthin.This research would provide the theoretical guidance and technical support for the development and utilization of seaweed fucoxanthin resource in the future.