Development of an analytical procedure for determination of selected estrogens and progestagens in water samples

An analytical procedure has been developed for determination of eight selected natural and synthetic hormonal steroids in surface water and in effluent samples. Several methodological points have been investigated and are discussed; they include the choice of the solid-phase extraction sorbent, the influence of flow rate on recovery, the breakthrough volume for a given sorbent (Env+ and Oasis HLB), sample clean up, and sample storage. As regards the latter point, it was found that when no preservative was added to effluent from a sewage-treatment plant, severe loss of steroids occurred—85% of progesterone and about 30% of both estrone and estradiol were found to be degraded in 24 h. The procedure developed was applied to samples from the Seine river estuary. Sex steroids were not detected in surface water; estrone was the most commonly detected steroid in sewage-treatment plant effluent, with levels ranging from 1.8 to 8.3 ng L^–1. Synthetic estrogens (ethynylestradiol and mestranol) and progestagens (levonorgestrel and norethindrone) were never detected, whatever the sampling season. Overall, for 162 out of 168 measurements levels were below the detection limits of the developed procedure.     

丙烯酸酯接枝炭黑无皂水性涂料的性能研究

旋转粘度计研究了丙烯酸酯接枝炭黑无皂水性涂料的流变性能，并考察了着色涂料的冻融及贮存稳定性。接枝炭黑争散于无皂水性涂料中形成的着色涂料具有良好的综合性能。     

New approach to calibrating conductivity meters in the low conductivity range

There is currently a major issue with the calibration of conductivity meters used for high purity water: the lack of availability of a reference material or reference methods for low conductivity ranges (conductivity below 1 S cm^–1 at 25.0 °C, resistivity >1 M cm at 25.0 °C). This paper describes the current status of conductivity measurements in high purity water. A new and improved approach, currently being investigated, should allow us to make the calibration of conductivity meters used for low conductivity ranges traceable to the SI.Milipore, Milli-Q and Elix are registered trademarks of Millipore Corporation.     

SOLUBILITIES OF POLYCYCLIC AROMATIC HYDROCARBONS AND DI-REGION THEORY

By using the relationship equation of Partition coefficients with water solubilities for polycyclic aromatic hydrocarbons (PAHs), we have estimated the solubilities of PAHs. In addition the high-performance liquid chromatograph (HPLC) method has been used for the indirect determination of solubilities of PAHs. t3ased on the di-region theory, We have studied the relationship of the solubilities of PAHs with carcinogenicity and introduced the solubility parameter into the di-region theory equation. The calculated carcinogenicity of PAHs from the obtained equation shows little difference from that calculated from Dai Qianhuan's equation.     

水煤气变换反应的微观动力学分析──Cu基催化剂上H_2S中毒失活原因的 Monte Carlo 模拟研究

用ＢＯＣＭＰ方法及ＭｏｎｔｅＣａｒｌｏ模拟技术，对Ｈ２Ｓ导致Ｃｕ基催化剂失活的原因进行了计算分析。研究结果表明，当原料气中存在Ｈ２Ｓ时，ＷＧＳ反应的活化能明显高于无Ｈ２Ｓ时的活化能，随着表面Ｈ２Ｓ浓度的增大（θ＝０，０．１０，０．２５），反应的活化能也逐渐变大（其大小比为１∶１．３４∶３．３），究其原因可归结为Ｈ２Ｓ的存在使得反应物分子的吸附热减小，从而使Ｈ２Ｏ的解离吸附（ＷＧＳ反应的速控步骤）活化能增大。     

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利用太阳能光解水制氢和降解有机污染物对解决能源和环境问题具有重要意义，而可见光响应催化剂的研制是实现太阳光高效利用的关键。本文从可见光响应光催化剂的设计思路出发，从电子能带结构、固溶体结构和微观复合结构三方面介绍了目前光催化剂的研究进展和发展方向。     

Rapid determination of panaxynol in a traditional Chinese medicine of Saposhnikovia divaricata by pressurized hot water extraction followed by liquid-phase microextraction and gas chromatography-mass spectrometry

Panaxynol is a bioactive component in traditional Chinese medicines (TCMs), such as Saposhnikovia divaricata and Panax ginseng. In the work, two solvent-free sample techniques of pressurized hot water extraction (PHWE) and headspace liquid-phase microextraction (HS-LPME) were combined and developed for the determination of panaxynol in a TCM of S. divaricata. Panaxynol in the TCM samples from different growing areas was extracted by PHWE in dynamic mode, followed by extraction and concentration with HS-LPME and analysis with gas chromatography-mass spectrometry (GC-MS). The PHWE and HS-LPME parameters were optimized and the method validations were studied. Panaxynol in S. divaricata from four different growing areas was quantitatively analyzed by internal standard method. These results have shown that PHWE-LPME-GC-MS is a simple, rapid, efficient and low-cost method for the determination of panaxynol in TCMs and is a potential tool for TCM quality assessment.     

Ion interaction approach to calculations of volumetric properties of aqueous multiple-solute electrolyte solutions

The ion interaction approach developed by Pitzer was used for the prediction of volumetric properties of mixed electrolyte solutions at 25°C based on parameters calculated from experimental data for single-solute electrolyte solutions. Such an approach was shown to be especially effective for application to the calculation of volumetric properties of natural hypersaline brines and of industrial electrolyte solutions of large complexity. The use of the latest recommended sets of volumetric ion interaction parameters for single electrolyte solutions and symmetrical mixing parameters for Na–K–Cl ion combinations considerably improved the precision of the density calculations of highly concentrated mixed electrolyte solutions and of various natural waters.     

Estimation of micropore size distribution in active carbons from adsorption isotherms of water vapor

A possibility of estimation of the micropore size distribution in the carbon adsorbents with the developed micro-and mesoporous structure by analysis of the adsorption isotherms of water vapors was considered. At saturation water condenses in micropores in a form of a weakly compressed liquid. However, water molecules in micropores are packed not so closely as in the liquid because of steric hindrance. Therefore, the real density of water adsorbed in the micropores is lower than that of water adsorbed on an open surface and lower than the density of the normal liquid. An analysis of the adsorption isotherms of water vapors with account for the both opposite effects on the water density gives reliable data on the micropore sizes of the carbon adsorbents. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 40–43, January, 2007.