Catalytic detoxification of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in fly ash.

An efficient catalytic detoxification method for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in fly ash produced by municipal waste incinerator has been studied using palladium on carbon (Pd/C) catalyst. As one of the trace components in fly ash, the detoxification of PCDD/Fs is very difficult because of the interferences of other persistent components with higher concentrations. However, the detoxification reaction of PCDD/Fs shows higher activity in water/isopropanol solution using commercial Pd/C catalyst at 40 degrees C under normal pressure.

Characterization of the surface properties of Mg/Al oxides by the solvation parameter model.

The oxides of different Mg/Al ratios (Mg/Al = 0, 0.1, 5, 10 and infinity) were prepared, and the characterization of these oxides was attempted by estimating characteristic interaction parameters based on the solvation parameter model. The magnitudes of the regression coefficients varied with the increase of Mg/Al ratio.

[Quick optimization of high performance liquid chromatographic conditions for separation of flavones of Astragalus].

An analytical method for flavones of Astragalus has been developed and a process of high performance liquid chromatographic (HPLC) condition optimization has been elaborated. The LC retention parameters of 34 components were obtained quickly by using three linear gradient elutions. Overlapping separation range map (OSRM), which is related to the separation quality and the analysis time, was utilized to search the optimised stepwise gradient method for HPLC analysis of flavones of Astragalus.

Gas chromatographic peak identification for polybrominated diphenyl ethers under different temperature programs.

A method has been developed for gas chromatographic peak recognition of polybrominated diphenyl ethers (PBDEs) under different temperature programs. On the basis of an identification database of retention parameters (A, B values) of gas chromatography and retention times of the selected internal standards, the retention times of BDEs can be accurately estimated. In comparison with the experimental retention values, the predicted retention times have been proved to be very accurate.

Identification of phenolic constituents in Radix Salvia miltiorrhizae by liquid chromatography/electrospray ionization mass spectrometry.

The phenolic components from Radix Salvia miltiorrhizae Bunge, a well-known herbal medicine (Dan-Shen in Chinese), have been investigated by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC/ESI-MS/MS). HPLC analyses were performed on a reversed-phase C18 column using gradient elution. In the ESI mass spectra a predominant [M-H]- ion was observed in negative mode and provided molecular mass information.

A noval method of predicting soil organic carbon content normalized adsorption coefficients (Koc) of polybrominated biphenyls (PBBs).

By a soil column liquid chromatograph (SCLC) method, the soil organic carbon content normalized adsorption coefficients (K(oc)) of six polybrominated biphenyls (PBB15, PBB26, PBB31, PBB49, PBB103 and PBB153) are determined. Based on the similarity between the molecular structures of PBBs and PCBs, a simple linear predictive model has been developed with the correlation coefficient R=0.9812 and standard error SE=0.

Unsymmetrical ferrocenylethylamine-derived monophosphoramidites: highly efficient chiral ligands for Rh-catalyzed enantioselective hydrogenation of enamides and alpha-dehydroamino acid derivatives.

[reaction: see text] A new family of unsymmetrical ferrocenylethylamine-derived monophosphoramidites were synthesized and successfully applied in the Rh-catalyzed enantioselective hydrogenation of a range of enamides and alpha-dehydroamino acid esters, and ee values of up to 99.5% were obtained for both types of substrate. These results suggest that unsymmetrical amine-derived monophosphoramidites can also exhibit excellent enantioselectivity for a broad range of substrates, comparable to or higher than those of the most efficient symmetrical amine-derived monophosphoramidites reported thus far.

Analysis of estrogenic compounds in Polygonum cuspidatum by bioassay and high performance liquid chromatography.

The estrogenic activity of traditional Chinese herb-Polygonum cuspidatum Sieb. et Zucc. was investigated by a recombinant yeast screening (YES) assay.

[Analysis of volatile constituents of root and rhizome of Asarum heterotropoides Fr. var. mandshuricum (Maxim.) Kitag. by gas chromatography-mass spectrometry].

The volatiles of root and rhizome of Asarum heterotropoides Fr. var. mandshuricum (Maxzim.

[Determination of anions in the products of ozonation of reactive dye by ion chromatography].

A method for the determination of anions in the degradation products of C. I. Reactive Red 120 by ozonation was investigated.

[Correlation between octanol-air partition coefficients and retention parameters of polychlorinated biphenyls on gas chromatographic columns].

Octanol-air partition coefficient (Koa) is a key descriptor for describing the partitioning of organic pollutants, especially persistent organic pollutants (POPs), between air and environmental organic phases. Thus it is necessary to determine or predict the Koa values of these compounds. A novel method was introduced to describe the quantitive relationship between the octanol-air partition coefficients and gas chromatographic (GC) retention parameters A, B values of polychlorinated diphenyls (PCBs) which are typical persistent organic pollutants.

Physicochemical characterization of the Strychnos alkaloids by capillary zone electrophoresis.

A capillary zone electrophoresis (CZE) method has been developed for investigating the physicochemical characteristics of five Strychnos alkaloids in Strychnos nux-vomica L. Firstly, the dissociation constants of the five Strychnos alkaloids were determined, based on the relation between the effective mobility of the solutes and the buffer pH. The mathematical relationship was strictly deduced from the fundamental electrophoretic theory and the dissociation equilibrium.

Development and application of a sol-gel immunosorbent-based method for the determination of isoproturon in surface water.

An immunosorbent was fabricated by encapsulation of monoclonal anti-isoproturon antibodies in sol-gel matrix. The immunosorbent-based loading, rinsing and eluting processes were optimized. Based on these optimizations, the sol-gel immunosorbent (SG-IS) selectively extracted isoproturon from an artificial mixture of 68 pesticides.

[Classification of terpenes and terpene oxides in volatile oil of Fruit of Acanthopanax senticosus (Rupr. Et Maxim) Harms with gas chromatographic retention parameters].

Gas chromatographic (GC) retention parameters (A and B values) for 24 volatile compounds in volatile oil of Acanthopanax senticosus (Rupr. Et Maxim) Harms were obtained from the retention times under five temperature-programming conditions with self-developed GC_AB software based on Levenberg-Marquardt method. The correlation analysis between A and B parameters of terpene and its oxides was carried out.

[Analysis of ginsenosides in ginseng by liquid chromatographyatmospheric pressure chemical ionization mass spectrometry].

Analysis of ginsenosides using high performance liquid chromatography-tandem atmospheric pressure chemical ionization mass spectrometry (HPLC-APCI/MS) has been carried out. HPLC analysis was performed on a reversed-phase C18 column using mobile phase of acetonitrile and water mixture under gradient elution. Effects of evaporation temperature of APCI-MS on identification of ginsenosides were investigated.

NaNO2-activated, iron-TEMPO catalyst system for aerobic alcohol oxidation under mild conditions.

FeCl3-TEMPO-NaNO2 catalyses the selective and mild aerobic oxidation of a broad range of alcohols to the corresponding aldehydes and ketones.

High-performance liquid chromatography-tandem mass spectrometry for identification of isoflavones and description of the biotransformation of kudzu root.

High-performance liquid chromatography-tandem mass spectrometry has been used to identify isoflavone aglycones and glycosides in kudzu root. Fourteen isoflavones were detected. Among these, six were identified by comparison with authentic standards.

[Analysis of the volatile oil from the stem of Acanthopanax senticosus (Rupr. et Maxim.) Harms with several hyphenated methods of gas chromatography].

Gas chromatography/quadrupole mass spectrometry (GC/qMS), gas chromatography/Fourier transform infrared spectrometry (GC/FTIR) and gas chromatography/orthogonal acceleration time-of-flight mass spectrometry (GC/oaTOFMS) were applied to analyze the volatile oil from the stem of Acanthopanax senticosus (Rupr. et Maxim.) Harms.

Identification of ginsenosides in roots of Panax ginseng by HPLC-APCI/MS.

A new HPLC-APCI/MS method for the identification of ginsenosides has been developed. The analyses were performed on a reversed-phase C18 column using a binary eluent (acetonitrile and water) under gradient conditions. Although APCI is a high-temperature evaporative process, HPLC-APCI/MS could effectively identify thermo-labile ginsenosides.

Distribution patterns of PCDD/Fs in chlorinated chemicals.

The purpose of this research was to determine polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) in five chlorinated chemicals (phthalocyanine copper, phthalocyanine green, chloranil-1 and 2, and triclosan), and to compare their 2,3,7,8-tetrachlordibenzo-IpI-dioxin equivalents (TEQ). The distribution patterns of total PCDD/Fs and 2,3,7,8-substituted PCDD/Fs were elucidated in detail. The TEQ values of toxic PCDD/Fs in all chemicals were in the range of 5.

Two new iridoid glycosides from the Tibetan folk medicine Swertia franchetiana.

Two new iridoid glycosides designated as senburiside III (2) and senburiside IV (3), together with one known iridoid glycoside senburiside I (1) and three known secoiridoid glucosides swertiamarin (4), gentiopicroside (5) and sweroside (6), were isolated from the whole plant of Swertia franchetiana. The structures of the two new compounds were elucidated by spectroscopic methods.

Prediction of octanol--air partition coefficients of semivolatile organic compounds based on molecular connectivity index.

A new method has been developed to describe the quantitative relationship between the octanol-air partition coefficients and molecular connectivity indexes of semivolatile organic compounds such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated naphthalenes (PCNs), polycyclic aromatic hydrocarbons (PAHs), chlorobenzenes (CBs), polybrominated diphenyl ethers (PBDEs). The stepwise multiple linear regression was used to derive six equations with correlation coefficients greater than 0.99 except for PBDEs' (0.

Analysis of the estrogenic components in kudzu root by bioassay and high performance liquid chromatography.

The estrogenic activity of the Chinese herb kudzu root was investigated by a recombinant yeast screening assay (YES). Isoflavones are the main components in the plant, of which puerarin is the most abundant one. The kudzu root extract was separated into four fractions according to the polarity.

Wet air oxidation of nitrobenzene enhanced by phenol.

Simultaneous nitrobenzene and phenol wet air oxidation was investigated in a stainless autoclave at temperature range of 180-220 degrees C and 1.0 MPa oxygen partial pressure. Compared with the single oxidation of nitrobenzene under the same conditions, the presence of phenol in the reaction media greatly improved the removal efficiency of nitrobenzene.