高效液相色谱-核磁共振光谱法测定纺织品及纺织助剂中烷基酚聚氧乙烯醚

建立了高效液相色谱-核磁共振光谱法测定纺织品及纺织助剂中烷基酚聚氧乙烯醚(APEO)的方法。用色谱保留时间及核磁共振光谱定性,色谱外标法定量,流动相为甲醇-乙酸铵溶液,紫外检测器检测波长为277 nm,APEO的质量浓度在5~250 mg.L-1范围内,浓度与峰面积呈线性关系,相关系数为0.992 8;保留时间的相对标准偏差小于0.21%,峰面积的相对标准偏差小于3.69%,回收率在91%~98%之间。纺织品中检测下限可达到1.0 mg.kg-1。该法已用于纺织品及纺织助剂的进出口检验。     

Synthesis and surface activity properties of alkylphenol polyoxyethylene nonionic trimeric surfactants

A series of trimeric n-alkylphenol polyoxyethylene surfactants (TAP) were successfully synthesized and the molecular structure were confirmed by NMR, FTIR spectrum and elemental analysis. Using the same synthesis route, the trimeric nonylphenol polyoxyethylene surfactant (TNP) was synthesized using industrial product nonylphenol and paraformaldehyde, and its molecular structure was characterized by ¹HNMR, FTIR spectrum and elemental analysis. The optimal reaction conditions were established. The surface activity properties of TAP and TNP (such as the critical micelle concentration (cmc), the values of surface tension at the cmc (γ_cmc), the maximum surface excess concentration (Γ_cmc), and the minimum surface area per surfactant molecule (A_cmc)), were determined by means of Wilhelmy plate method and steady-state fluorescence probe method, respectively. The experimental results show that the lengths of the hydrophilic group oxyethylene (EO) chains and hydrophobic group methylene chains have an influence on the cmc, γ_cmc, Γ_cmc, and A_cmc of series of surfactants. Furthermore, TAP are arranged to staggered three-dimensional array mode at the air-water interface, which has exhibited better surface properties, such as low cmc values, strong adsorption affinities and wet abilities.     

Determination of nonylphenol ethoxylates in the aquatic environment by normal phase liquid chromatography-electrospray mass spectrometry

A comprehensive analytical method based on normal-phase liquid chromatography–electrospray ionization mass spectrometry (NPLC–ESI-MS) has been established for determination of nonylphenol ethoxylates (NPEOs) in the aquatic environment. Extraction and cleanup of samples were performed on graphitized carbon black (GCB) solid-phase extraction cartridges. Complete separation between each individual NPEOs was achieved by combining a C₁₈ pre-column with a silica analytical column and using acetonitrile–water as eluent. Quantitative determination by LC–ESI-MS was achieved in the positive ionization (PI) mode at a ramped cone voltage for NPEOs using selected ion monitoring. Recoveries for NPEOs ranged between 91.9 and 117.5%, and the limits of detection varied between 0.5 and 2 ng/l for individual NPEOs with n longer than 2, and between 5 and 0.5 μg/l for NP1EO and NP2EO. This method was successfully applied to the investigation of residual NPEOs with n>2 in the Chongqing area of the Changjiang river. NPEOs with n ranging from 1 to 22 were found to vary between 0.1 and 2900 ng/l with a distribution depending on the depth of water.     

Sterol surfactants: from synthesis to applications

An overview is given of sterol surfactants, including raw material aspects, classification and synthesis routes, physico-chemical behaviour and applications in pharmaceuticals and cosmetics.     

Development and optimisation of a GC-MS method for the evaluation of oestrogens and persistent pollutants in river and seawater samples

This paper describes the development and validation of a GC-MS method which allows the simultaneous quantification of 11 endocrine disrupting compounds (EDCs) in surface water samples from both estuary and sea. The analysed EDCs are oestrone (E1), 17β-estradiol (E2), 17α-ethynylestradiol (EE2), 4-tert-octylphenol, 4-n-octylphenol, 4-nonylphenol, bisphenol A and finally, mono and diethoxylates of 4-nonylphenol and 4-octylphenol. The method includes the pre-concentration of water samples, 1000-fold factor, in OASIS HLB cartridges by solid phase extraction, the derivatisation of all EDCs by N,O-bis(trimethylsilyl)trifluoroacetamide added with 1% trimethylchlorosilane and pyridine (at 65°C for 30?min) and, finally the stabilisation of the EDCs-silylated derivatives, in hexane, for 72?h. The validation parameters revealed that this method was highly specific for all target compounds using real samples. The linearity of the calibration curves (r ²) showed correlation factors higher than 0.990. The detection limits ranged from 0.10 to 1.45?ng?L^?1, depending on each analysed compound, and recoveries were satisfactory for most of the assayed EDCs (>60%). Analysis of samples from four polluted areas of Douro River estuary and from two points of the Atlantic Ocean (Portugal) showed high amounts of E1 (up to 1.96?ng?L^?1), E2 (up to 14.36?ng?L^?1) and EE2 (up to 2.76?ng?L^?1).