Simple Pretreatment Method for Monitoring of Norephedrine in Urine and Tyramine in Food Sample Using Liquid-Liquid Extraction

抄録

Norephedrine and tyramine are familiar as sympathetic nerve-stimulating chemicals. Analysis of norephedrine in urine sample is necessary for the evaluation of intake. Analysis of tyramine in food samples is also necessary for evaluation of its daily intake. However, both are difficult to extract by conventional liquid-liquid extraction. The present work proposed to monitor both using a small amount of a mixture of two solvents. For norephedrine, a filtrate (100ml) of human urine sample (pH11) was mixed with 5% sodium dodecyl sulfate solution (100μl) and acetone (2.5ml), then shaken with chloroform (2.5ml). This method recovered 5-10% of norephedrine added. For tyramine, a filtrate (5ml) of intact or concentrated sample solution (pH11) was salted out with NaCl (1g), then shaken with a mixture of acetone (3ml) and ethyl ether (2ml). This method recovered 50-60% of tyramine added.