提出了液相色谱-串联质谱法同时测定浓缩胡萝卜汁中苏丹橙G、苏丹红G、苏丹红7B、苏丹黄、苏丹红Ⅰ、苏丹红Ⅱ、苏丹红Ⅲ、苏丹红Ⅳ等8种苏丹类染料含量的方法。样品经正己烷提取,于39 ℃旋转蒸发至近干,氮气吹干后用1 mL乙腈和0.1%(体积分数,下同)甲酸(1+1)混合液溶解。采用Hypersil GOLD色谱柱(50 mm×2.1 mm,1.9 μm)为分离柱和以不同比例的0.1%甲酸和甲醇混合液为流动相作梯度淋洗,采用多反应监测正离子模式监测。8种苏丹类染料的质量浓度均在30~100 μg·L-1范围内呈线性,测定下限(10S/N)在5~30 μg·kg-1之间。在3个浓度水平下做加标回收试验,回收率在72.0%~96.0%之间,测定值的相对标准偏差(n=6)在6.2%~9.6%之间。

LC-MS/MS was applied to the determination of 8 Sudan dyes, i.e., Sudan orange G, Sudan red G, Sudan red 7B, Sudan yellow, Sudan red Ⅰ, Sudan red Ⅱ, Sudan red Ⅲ and Sudan red Ⅳ, in concentrated carrot juice. The sample was extracted by n-hexane, concentrated to near dryness in a rotary evaporator at 39 ℃, and evaporated to dryness by N2-blowing. The residue was dissolved with 1 mL of a mixed solvent of methanol and 0.1% (φ) formic acid (1+1). Hypersil GOLD (50 mm×2.1 mm, 1.9 μm) column was used as chromatographic column, and mixtures of methanol and 0.1% (φ) formic acid in various ratios were used as mobile phase in the gradient elution; positive electrospray ionization as well as multiple reaction monitoring mode was used in the detection. Linear relationships between values of peak area and mass concentration of 8 Sudan dyes were kept in the same range of 30-100 μg·L-1, with lower limits of determination (10S/N) in the range of 5-30 μg·kg-1. Tests for recovery were made by addition of standard solutions at 3 different concentration levels, values of recovery found were in the range of 72.0%-96.0%, with values of RSD′s (n=6) in the range of 6.2%-9.6%.