溶剂萃取-高效液相色谱法测定油脂类食品中荧光增白剂1,4-二苯基-1,3-丁二烯的迁移量

将所选取的8种油脂类食品捣碎并均匀化后称取5.00(±0.01)g,用乙腈提取2次(每次用10.0mL),振荡3min,离心,每次取其上清液1.0mL,将2次上清液合并,加入水1.3mL,用0.45μm滤膜过滤,滤液作为试液用于高效液相色谱(HPLC)测定。用Agilent Eclipse XDB-C8色谱柱作为固定相,以不同比例的(A)水和(B)乙腈的混合液作为流动相进行梯度洗脱;在波长330nm处,用二极管阵列检测器(DAD)检测1,4-二苯基-1,3-丁二烯(DPBD)在保留时间13.01min时的峰面积。测得DPBD的质量浓度在0.01~50.0mg·L^-1内与其相应的峰面积呈线性关系,其检出限(3s)为0.01mg·kg^-1。以8种食品的空白样品为基体,分别加入3个浓度水平的DPBD标准溶液进行精密度和回收试验,测得回收率为80.1%~119%,测定值的相对标准偏差(n=6)为1.8%~12%。称取所选取的8种样品,分别置于含有DPBD(12.58mg·kg^-1)且相同规格的聚乙烯(PE)食品袋中,抽真空密封。将此密封的8袋食品按GB 31604.1-2015的方法,在不同的迁移条件下进行DPBD从食品袋向食品的迁移试验,并按上述方法测定其含量。试验结果表明DPBD容易向表面油脂含量高的煎炸类食品迁移,在3种煎炸食品中,在不同的迁移条件(温度及时间)下测得的DPBD含量为0.17~0.47mg·kg^-1,而在其余的5种食品中均未测出DPBD。

Determination of the Migration Amount of 1,4-Diphenyl-1,3-Butadiene,a Fluorescent Whitening Agent,in Oil Foodstuffs by Solvent Extraction-HPLC

Eight kinds of oily foodstuffs were chosen as samples for study and were pounded and homogenized separately.(5.00±0.01)g of the sample were taken and extracted twice with acetonitrile(10.0 mL for each extraction)for 3 min under shaking.After centrifuging,1.0 mL ofthe supernatant was taken,and the 2 supernatants were combined,to which 1.3mL of water was added,and the solution was filtered through 0.45μm fitering membrane.The filtrate was used for HPLC analysis.Agilent Eclipse XDB-C8 column was used as a stationary phase,and mixed solvents of(A)water and(B)acetonitrile with various ratios were used as mobile phases in the gradient elution.Data of peak area of 1,4-diphenyl-1,3-butadiene(DPBD)were measured by DAD at 330nm and retention time of 13.01min.Linear relationship was found between values of mass concentration of DPBD in the range of 0.01-50.0mg·L^-1 and the corresponding peak areas;with detection limit(3s)of 0.01mg·kg-1.Using the blank samples of the 8selected foodstuffs as matrixes,test for precision and recovery by adding standard DPBD solution at 3concentration levels were made,giving results of recovery in the range from 80.1%-119%,and RSDs(n=6)ranged from 1.8%-12%.Eigh PE bags with same specification and containing same amounts of DPBD(12.58mg·kg-1)were taken and the 8foodstuffs(5.00g each)were added separately into the PE bags.Then the bags were sealed up under vacuum,and tested for the migration of DPBD from the PE bags to the foodstuffs according to the method described in GB 31604.1-2015,with DPBD determined by HPLC as described above.It was found that the DPBD was easier to migrate into the fried foodstuffs with high oil or fatcontents on their surfaces.As tested under different migration conditions of temperature and time,amounts of DPBD found in 3fried foodstuffs were ranged from 0.17-0.47mg·kg^-1;while no migrations of DPBD were found in the 5remainder foodstuffs.