Anisoin: A useful pre-chromatographic derivatization fluorogenic reagent for LC analysis of guanidino compounds

The use of anisoin as pre-chromatographic reagent for LC analysis of guanidino compounds is proposed. The reagent reacts (5 min at 100 °C) with guanidino function and the resulting adducts can be chromatographed under reversed-phase conditions. A fluorescence detector (λex = 325 nm; λem = 435 nm) was used to detect guanidino adducts. The derivatization and chromatographic conditions were optimised by a series of experiments. Application to the determination of arginine and creatine in pharmaceuticals and arginine, guanidine, methylguanidine, guanidinosuccinic acid, β-guanidinopropionic acid, γ-guanidinobutyric acid, guanidinoacetic acid and homoarginine in human urine is described. Quantitation limits ranged from 6 to 30 fmol, except for creatine (510 fmol).