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91.
Summary Ten heterocyclic aromatic amines (HAA) (1)–(10) were analyzed in commercially available meat products and fish. After sample preparation by Extrelut treatment and subsequent
solid phase extraction applying propylsulphonic and C18 silica cartridges, HPLC-ESI-MS-MS using selected reaction monitoring (SRM) and d3-PhIP and d3-MeIQx as internal and external standards, respectively, revealed the widely distributed presence of PhIP (8) and MeIQx (4), ranging from 0.1 to 5.3 ng g−1 and 0.1 to 5.2 ng g−1, respectively. Lower amounts were found for 4,8-DiMeIQx (5) and 7,8-DiMeIQx (6), ranging from 0.2 to 2.0 ng g−1 and 0.1 to 0.2 ng g−1, respectively. The other HAA under study, i.e. IQ, MeIQ, 4,7,8-TriMeIQx, Glu-P-1, and Glu-P-2 were not determinable under
the experimental conditions used (determination limit 0.1 ng g−1). 相似文献
92.
Summary A simple and sensitive method has been developed for the liquid chromatographic determination of short-chain aliphatic amines
in water. Analytes are retained in solid-phase extraction (SPE) cartridges, and then derivatized by drawing an aliquot of
the fluorogeneic reagent 9-fluorenylmethyl chloroformate (FMOC) through the cartridges. After a certain reaction time the
derivatives formed are desorbed with acetonitrile. The collected extracts are then chromatographed on a LiChrospher 100 RP18 125 mm×4 mm i.d., 5 μm, column using an acetonitrile-water gradient. The influence of experimental conditions (SPE material,
volume of sample, concentration of FMOC, time of reaction and pH) has been investigated. Optimal results have been obtained
with C18 SPE cartridges using a sample volume of 5.0 mL. For derivatization, 0.25 mL aliquots of 25 mM FMOC have been used, the reaction
time being only 2 min. The method has been applied to the quantification of several aliphatic amines: methylamine, ethylamine,
dimethylamine,n-butylamine,n-pentylamine andn-hexylamine. Under the proposed conditions the percentages of analytes retained plus derivatized were of about 54–107% compared
to those obtained with direct solution derivatization. The method provided good reproducibility, linearity and accuracy within
the 0.050–1.0 mg L−1 concentration range. The limits of detection were in the 0.25–5.0 μg L−1 range. The utility of the described approach has been tested by analysing tap water, river water and industrial waste water. 相似文献
93.
94.
95.
An extremely short synthesis of 2,2-dimethyl-3-hydroxymethyl cyclopentanone 2 (R1 = R2 = Me), an advanced intermediate in the synthesis of the pheromone planococcyl acetate 3, is described. 相似文献
96.
Investigations on a new class of polyamides obtained by interfacial polycondensation from amine-chloral derivatives, e.g., 2,2-bis(p-aminophenyl)-1,1,1-trichloromethane or 2,2-bis(p-aminophenyl)-1, 1-dichloroethylene and terephthaloyl chloride, have been carried out. It was found that the interfacial process proceeds in the most advantageous way in acidic medium at 0°C using equivalent volume amounts and equimolar concentrations of methylene chloride and water phases in the presence of a stoichiometric quantity of triethylamine as the hydrogen acceptor. 相似文献
97.
Mohammad Reza Islami Zahra Hassani Hassan Sheibani 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):2547-2554
Phthalimide or succinimide undergo a reaction with dialkyl acetylenedicarboxylates and triphenylphosphine to produce highly-functionalized stable heterocyclic phosphorus ylides in good yields in water-tetrahydrofuran (6:1). This methodology is of interest because of the use of water as solvent, thus minimizing the cost, operational hazards, and environmental pollution. 相似文献
98.
Tharwat Mohy El Dine David Evans Prof. Jacques Rouden Dr. Jérôme Blanchet 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(17):5894-5898
A highly efficient and mild transamidation of amides with amines co‐catalysed by borinic acid and acetic acid has been reported. A wide range of functionalised formamides was synthesized in excellent yields, including important chiral α‐amino acid derivatives, with minor racemisation being observed. Experiments suggested that the reaction rely on a cooperative catalysis involving an enhanced boron‐derived Lewis acidity rather than an improved Brønsted acidity of acetic acid. 相似文献
99.
100.
Aza-Michael reactions between primary amines and methyl propenoate have been investigated under environmentally-friendly solventless heterogeneous catalysis in order to obtain the mono- or the bis-adduct. The reaction conditions can be altered so as to maximise the yields of the required product with high selectivity. 相似文献