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A simple, sensitive, and mild method for the determination of amines based on a condensation reaction with 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC · HCl) as the dehydrant with fluorescence detection has been developed. Amines were derivatized to their acid amides with labeling reagent 4-s(1-methyl-1H-phenanthro[9,10-d]imidazole-2-) benzoic acid (MPIBA). Studies on derivatization conditions indicated that the coupling reaction proceeded rapidly and smoothly in acetonitrile to give the corresponding sensitively fluorescent derivatives with a maximum excitation at λex 260 nm and a maximum emission at λem 446 nm. The labeled derivatives exhibited high stability and were enough to be efficiently analyzed by high-performance liquid chromatography. Identification of derivatives was carried out by online post-column mass spectrometry (LC/APCI-MS/MS) and showed an intense protonated molecular ion corresponding m/z [MH]+ under APCI in positive-ion mode. At the same time, the fluorescence properties of derivatives in various solvents were investigated. The method, in conjunction with a gradient elution, offered a baseline resolution of the common amine derivatives on a reversed-phase Eclipse XDB-C8 column. Liquid chromatography separation for the derivatized amines showed good reproducibility with acetonitrile-water as mobile phase. Detection limits calculated from 90.00 pmol to 88 fmol injection, at a signal-to-noise ratio of 3, were 10.5-53.4 fmol. Excellent linear responses were observed with coefficients of >0.9996. The established method for the determination of aliphatic amines from real wastewater was satisfactory. [ABSTRACT FROM AUTHOR]

Abstract: The extraction parameters for oil extraction from Lycium barbarum seed including extraction pressure, temperature and time were optimized using an orthogonal test design. The optimum conditions for supercritical CO2 extraction were as follows: extraction pressure, 30MPa; extraction temperature, 45°C; dynamic extraction time, 60min; CO2 flow, 25kg/h. The oil yield under the conditions proposed was 19.28g/100g. The effect of cell wall breakage pretreatment was investigated by supercritical CO2 rapid depressurization, and results indicated this pretreatment could result in a rapid and efficient extraction. A sensitive fluorescent reagent 2-(11H-benzo[a]carbazol-11-yl) ethyl 4-methylbenzenesulfonate (BCETS) was utilized as pre-column labeling regent to determine fatty acids (FA) from Lycium barbarum seed oils obtained by different extraction methods. The main FA were: C18:2, C18:1, C16, C20:6, C18:3, and C20. The oil from L. barbarum seed exhibited excellent antioxidant activity in 2,2-diphenyl-1-picrylhydrazyl（DPPH）radical scavenging assay and β-carotene bleaching test, and its antioxidant activity compared well with the references ascorbic acid and α- tocopherol. [ABSTRACT FROM AUTHOR]