食品中苏丹染料的高效液相色谱-离子阱质谱分析

HPLC-ION TRAP MS ANALYSIS OF SUDAN DYES IN FOODSTUFFS

提出了用高效液相色谱-离子阱质谱联用法同时鉴定和分析食品中四种苏丹染料的方法,色谱柱为Agilent Zorbax XB-C18,采用ESI离子源,离子阱质谱进行二级质谱分析,分析了苏丹染料分子在质谱中的碎裂方式,对碰撞解离电压进行了优化选择.方法检出限为1μg·L-1,线性范围为5～100μg·L-1,回收率在85.5%～97.0%之间.

Four kinds ot sudan dyes （. i. e. sudan Ⅰ , Ⅱ , Ⅲ and Ⅳ）determined simultaneously by the hyphenation of HPLC and ion-trap MS/MS. The powdered sample （10 g） was shaked with 50 mL of methyl alcohol for 10 min and treated ultrasonically in a water bath for 15 min. After standing, the mixture was filtered and the filtrate was introduced directly into the hyphenated analytical instrument. The Agilent zorhax XB-C18 （150 mm× 2. 1 mm, 5 μm） was used as chromatographic column for the separation of the four dyes. A mixture containing acetic acid water solution （1＋999） and methyl cyanide in the proportion of 15 to 85 was used as the mobile phase at a flow-rate of 0. 3 mL · min^-1. ESI-Ion-trap MS/MS was used in the MS analysis. The intellectual condition-selection mode of the Agilent 1 100 ion-trap mass-spectrometer was used in the MS analysis, and the quasi-molecule-ions [M-kH]^＋ of the 4 dye compounds, having m/z 249, m/z 277, m/z 353 and m/z 381 were taken as the reference ions under the given MS conditions, according to the time of peak appearance of these compounds respectively. Typical and stable MS spectrum of the respective compounds were obtained. Fragmentation of the molecules was studied and the voltage of collision dissociation was optimized. Detection limit of the method was found to be 1 μg · L^-1 〈 and the linear range of response was in the range from 5 μg to 100μg per liter. Results of recovery test were in the range from 85.5% to 97.0%.