Simultaneous high-performance liquid chromatographic determination of ochratoxin A and citrinin in cheese by time-resolved luminescence using terbium

摘要: Abstract A simultaneous reversed-phase HPLC determination of two major mycotoxins, ochratoxin and citrinin, in soft cheese is proposed. Both mycotoxins are eluted on a C18 RP support (25 × 4.6 mm I.D.) using an isocratic eluent consisting methanol-water (70:30, v/v) containing tetrabutylammonium hydroxide (10−3 M), acidified to pH 5.5 with HCl, pumped at flow-rate 0.8 ml/min. Prior detection, butanolic solution 5·10−3 M terbium-5 · 10−4 trioctylphosphine oxide (TOPO)-2.5 10−2 triethylamine (TEA) was postcolumn mode 0.2 ml/min perform time-resolved luminescence (TRL) detection the corresponding terbium chelates (λex = 331 nm/λem 545 nm). The method linear from 3.5·10−6 2·10−5 for citrinin 1·10−5 5·10−5 A. repeatability reproducibility (R.S.D.) 1.9 2.4% (c M; n 10), 7.2 8.3% 1.0·10−5 10). limits signal-to-background ratio 3, 2·10−6 3·10−6 A, respectively. With proposed method, citrin easily determined cheeses, significative increase selectivity comparison direct fluorescence detection.