A method for determination of 6 plant growth regulators by high performance liquid chromatography-tandem mass spectrometry ( HPLC-MS/MS ) coupled with isotope-coded derivatization was developed. d0-10-Methyl-acridone-2-sulfonyl piperazine ( d0-MASPz, light form) and d3-10-methyl-acridone-2-sulfonyl piperazine ( d3-MASPz, heavy form ) were prepared as isotope-coded derivatization reagents for carboxyl compound. The carboxyl plant growth regulator standards and real samples were derivatized by d0-MASPz and d3-MASPz, respectively. The obtained solutions were mixed at a certain ratio, and then injected for HPLC-MS/MS analysis. The light and heavy derivatives were monitored with transitions of [M+H]+m/z 208. 2 and [M+H]+ m/z 211. 2,respectively. With heavy derivative as internal standard for corresponding light derivative, the global isotope internal standard quantification for 6 plant growth regulators was achieved. The results indicated that the proposed isotope-coded derivatization method could provide relative quantitative data with adequate linearity in a 10-fold dynamic range ( R=0 . 9991 ) . The detection and quantitation limits were 0. 19-0. 34 μmol/L and 0. 53-0. 96 μmol/L, respectively. The relative standard deviations were ≤3 . 8%, and the accuracies ranged from 97 . 5% to 103 . 8%.

Aliphatic amines in infant food packaging materials were extracted and concentrated by 0 . 5 mL of acidified methanol using gas purge microsyringe extraction ( GP-MSE ) . Pre-column fluorescence labeling of amines was achieved in mild conditions with 10-ethyl-acridine-2-sulfonyl chloride ( EASC ) as labeling reagent. The derivatization was carried out at 60℃ and pH 10. The derivatives were successfully separated on a Hypersil GOLD column with excitation and emission wavelengths of 262 and 430 nm, respectively. The detection limits were in the range of 0. 4-0. 6 μg/kg, and the quantitation limits were in the range of 1. 2-2. 1 μg/kg. All analytes were in good linearity in the concentration range of 2. 0-2000 μg/L with correlation coefficients of higher than 0. 998. The developed method was characterized by celerity, accuracy and high sensitivity. It was successfully applied to the determination of aliphatic amines in infant food packaging materials.

With comparison of three different methods for the marking of amines compound, an optimal deri vatization method was selected.5-(2-Hydroxyethyl) benzoacridine (HBA) reacts with coupling agent N,N'-carbonyldiimidazole(CDI) to form an activated amide intermediate 2-(benzoacridin) ethyl-imidazole-1-carbox-ylate(BAEIC).BAEIC, which is dual-sensitive probe, reacts preferably with amino compounds at 80 ℃ in the presence of 4-dimethylaminopyridine(DMAP) catalyst in N,N-dimethylformamide(DMF) solvent to give the corresponding sensitively fluorescent derivatives with an excitation maximum at λ_(ex) of 280 nm and an emis sion maximum at λ_(em) of 510 nm.BAEIC-amine derivatives simultaneously exhibited high ionization potential with percent ionization (changing from 5.62% to 58.08% in aqueous acetonitrile and from 2.14% to 56.58% in aqueous methanol.Derivatives were not only sensitive to fluorescence but also to MS ionizable potential.The fluorescence detection limits(5/iV = 3) were 0.12-0.59 μg/L.The online APCI-MS detection limits were 1.9-14 μg/L(S/N=5).