Abstract:

On a reversed-phase Hypersil BDS C₁₈(4.6 mm×200 mm, 10 μm i.d.) column, 12 aliphatic amines were derivatized using 10-ethyl-9-oxo-9,10-dihydroacridine-2-sulfonyl chloride(EASC) as a new pre-column derivatization reagent. The complete baseline resolution was obtained in conjunction with a gradient elution with acetonitrile/H₂O as mobile phase within 20 min. The optimum excitation and emission wavelengths were at λ_ex/λ_em=270 nm/430 nm. Comparing with the widely used Dansyl-Cl, EASC has stronger photoluminescence characteristics(ultraviolet and fluorescence): UV_EASC/UV_Dansyl-Cl=3.2(UV: ultraviolet absorption intensity); I(EASC)/I(Dansyl-Cl)=30.0∶1—105.4∶1(I: relative fluorescence intensity); fluorescence quantum yield: Φ_f(EASC)/Φ_f(Dansyl-Cl)=43.0∶1. Fast and accurate quantitative analysis of aliphatic amines with fluorescence and corresponding post-column ion trap mass spectrometry(LC-APCI-MS) were obtained. EASC-amines exhibited stronger mass spectrometric sensitivity relative to that of dansyl-amine derivatives: MS_EASC/MS_Dansyl-Cl=1.6∶1—6.2∶1 times(MS: relative intensity of ion current). The established method for the determination of aliphatic amines in environmental water samples exhibited good reproducibility and recovery. Excellent linear responses were observed with the correlation coefficients >0.9995. The detection limits(at signal-to-noise of 3∶1) were at levels of 4.0—12.7 fmol.

Key words: High performance liquid chromatography/ion-trap mass spectrometry, Fluorescence detection, Pre-column derivatization, 10-ethyl-9-oxo-9,10-dihydroacridine-2-sulfonyl chloride, Aliphatic amine