Research On An Efficient Detection Technology Of Various Fluorescent Whitening Agents In Food Packagino Materials

In recent years,more and more attention has been paid to food safety.Studies have shown that food contact packaging materials directly affect the quality of food.In order to change the appearance of food packaging,some illegal merchants add fluorescent whitening agents illegally to the packaging materials.When the fluorescent whitening agents combined with proteins in the human body,accumulation effect will be produced and it is hard to excreted through normal metabolism.Such as long-term use,the fluorescent whitening agents will store up to a certain amount to cause severe damage to the viscerals.There is even a possibility of cancer.We selected the paper food packaging materials collected in Zhejiang Province as samples.The sample is fully crushed,then it is extracted and centrifuged several times.The extract was analyzed by ultra high performance liquid chromatography(UPLC).Use the acetonitrile/methanol(2:3,V/V)mixed solution and aqueous methanol solution(5:95,V/V)containing 25 mmol TBA as mobile phase to make gradient elution separation.Use the ACQUITY UPLC BEH C18 chromatographic column to simultaneous detect the contact of 11 fluorescent whitening agents(C.I.85、C.I.113、C.I.353、C.I.220、FWA5bm、C.I.71、C.1.90、C.I.24、C.I.210、C..264、C.I.357)qualitatively and quantitatively with ultra performance liquid chromatography tandem fluorescence detector and diode array detector(UPLC-FLD/PDA)dual detector combination.The results showed that the 11 fluorescent whitening agents obtained good separation,For both detectors of FLD and PDA,in the linear range of 25-1000 ng/mL,the correlation coefficient was greater than 0.99,and the recoveries of spiked recoveries were between 81.1%-105.7%with the RSD less than 10%(n=6).The detection limit is calculated according to the 3 times signal-to-noise ratio of the instrument,and the quantitative limit is calculated in accordance with the signal-to-noise ratio of 10 times the instrument,the etection limits of 11 fluorescent whitening agents are:2.0-2.8 ng/mLfor FLD and 14～25 ng/mL for PDA.Quantitative limits for 11 fluorescent whitening agents are:6.7-9.3 ng/mLfor FLD and 47-83 ng/mL for PDA.The result shows that this method is an efficient quantitative method for the determination of fluorescent whitening agents in paper food packaging materials and can meet the needs of practical work.Meanwhile this method can make up for the vacancy of the existing national standards,increase the technical reserves and provide technical support for market supervision.