气相色谱法测定间甲苯酚含量

This paper describes a method for the assay of m-cresol content in it' s technical product which containso-,m-,and p-nitrotoluene and o-,m-,and p-toluidine. The analysis was performed on a BP20 silica capillary column. The method meets the needs of technical analysis.     

Allele-specific amplification and electrochemiluminescence method for single nucleotide polymorphism analysis

A new approach combined the specificity of allele-specific amplification (ASA) with the sensitivity of electrochemilu- minescence (ECL) assay for single nucleotide polymorphism (SNP) analysis was proposed. Briefly, target gene was amplified by a biotin-labeled allele-specific forward primer and a Ru(bpy)32 (TBR)-labeled universal reverse primer. Then, the amplicon was captured onto streptavidin-coated paramagnetic beads through biotin label, and detected by measuring the ECL signal of TBR label. Different genotypes were distinguished according to the ECL values of the amplicons by different genotypic primers. K-ras oncogene was used as a target to validate the feasibility of the method. The experiment results show that the different genotypes can be clearly distinguished by ASA–ECL assay. The method is useful in SNP analysis due to its sensitivity, safety, and simplicity.     

Sensitive analysis of amino acids in injection liquor by reversed-phase HPLC

A convenient derivatization method of amino acids with l-fluoro-2,4-dimtrobenzene as reaction reagent and a separation system were described. The derivative amino acids were separated on a specific chemically bonded phase column with a simple linear gradient elution consisting of aqueous buffer and methanol. The eluate was detected by common ultraviolet absorption detector at 360 nm. The detection limits of amino acids were as low as 10 picomole. This method has been successfully applied to assay amino acid injection liquor used in hospital. It has good repro-ducibility and precision. The procedures avoid the requirements of particular derivative equipment and analyzer employed in conventional amino acid analysis.     

In situ formation of fluorescent silicon-containing polymer dots for alkaline phosphatase activity detection and immunoassay

The discovery and application of analyte-triggered fluorophore generation or fluorogenic reaction are significant and beneficial to the development of novel fluorescence(FL) analysis method. In this study, for the first time, we have reported a fluorogenic reaction to prepare fluorescent silicon-containing polymer dots(Si-PDs) by simply mixing N-[3-(trimethoxysilyl)propyl]ethylenediamine(DAMO) and hydroquinone(HQ) in aqueous solution at ambient temperature. Inspired by the alkaline phosphatase(ALP)-catalyzed hydrolysis of the substrate sodium 4-hydroxyphenyl phosphate(4-HPP) into HQ and the resultant HQcontrolled intense green Si-PDs generation, we have established a straightforward ALP activity assay by innovatively employing commercially available 4-HPP as the substrate. More significantly, the specific preparation method, clear formation mechanism and excellent performance enable the Si-PDs as well as its generation process to develop facile and attractive FL immunoassay.With the help of the universal ALP-based enzyme-linked immunosorbent assay(ELISA) platform and corresponding antibody, a convenient and conceptual ALP-based fluorescent ELISA has been constructed and applied in sensing cardiac troponin Ⅰ(cTnI),a well-known biomarker of acute myocardial infarction. Our research via in situ formation of fluorescent nanomaterials has great potential application in ALP activity assay, inhibitor screening, and disease diagnosis.     

Synthesis and anticancer activities of porphyrin induced anticancer drugs

In view of the property of porphyrin's accumulation selectively in tumor,the ftorafur was modified by binding a porphyrin block to improve its tumor targeting and reduce its side effects.These novel porphyrin derivatives and metal compounds were synthesized under mild conditions with satisfactory yield,and the constructions of all these new compounds were characterized by UV,IR,MS, ~1H NMR spectra and elementary analysis.Their anticancer activities were evaluated by MTT assay;the results indicated that the anticancer activities of compounds 4a-c were twice as high as that of ftorafur.     

An improvement of window factor analysis for resolution of noisy HPLC-DAD data

Window factor analysis (WFA) is a powerful tool in analyzing evolutionary process. However, it was found that window factor analysis is much sensitive to the noise involved in original data matrix. An error analysis was done with the fact that the concentration profiles resolved by the conventional window factor analysis are easily distorted by the noise reserved by the abstract factor analysis (AFA), and a modified algorithm for window factor analysis was proposed. Both simulated and experimental HPLC-DAD data were investigated by the conventional and the improved methods. Results show that the improved method can yield less noise-distorted concentration profiles than the conventional method, and the ability for resolution of noisy data sets can be greatly enhanced.     

A Novel Real-time Fluorescence Mutant-allele-specific Amplification Method for Rapid Single Nucleotide Polymorphism Analysis

Current methods for single nucleotide polymorphism (SNP) analysis are time-consuming and complicated. We aimed at development of one-step real-time fluorescence mutant-allele-specific amplification (MASA) method for rapid SNP analysis. The method is a marriage of two technologies: MASA primers for target DNA and a double-stranded DNA-selective fluorescent dye, SYBR Green I. Genotypes are separated according to the different threshold cycles of the wild-type and mutant primers. K-rar oncogene was used as a target to validate the feasibility of the method. The experimental results showed that the different genotypes can be clearly discriminated by the assay. The real-time fluorescence MASA method will have an enormous potential for fast and reliable SNP analysis due to its simplicity and low cost.     

A variable differential consensus method for improving the quantitative near-infrared spectroscopic analysis

Consensus methods have presented promising tools for improving the reliability of quantitative models in near-infrared(NIR) spectroscopic analysis.A strategy for improving the performance of consensus methods in multivariate calibration of NIR spectra is proposed.In the approach,a subset of non-collinear variables is generated using successive projections algorithm(SPA) for each variable in the reduced spectra by uninformative variables elimination(UVE).Then sub-models are built using the variable subsets and the calibration subsets determined by Monte Carlo(MC) re-sampling,and the sub-model that produces minimal error in cross validation is selected as a member model.With repetition of the MC re-sampling,a series of member models are built and a consensus model is achieved by averaging all the member models.Since member models are built with the best variable subset and the randomly selected calibration subset,both the quality and the diversity of the member models are insured for the consensus model.Two NIR spectral datasets of tobacco lamina are used to investigate the proposed method.The superiority of the method in both accuracy and reliability is demonstrated.     

Label-free quantification of peptides in solution by disposable patterned hydrophilic chip based MALDI imaging

Quantification of a mixture of peptides in solution was achieved by disposable patterned hydrophilic chip based matrix-assisted laser desorption/ionization mass spectrometric imaging(MALDI MSI).Compared with other quantitative methods for peptides in solution, this method is label-free and does not require separation of the multiple components of the solution before analysis. Uniform hydrophilic spots and high mass accuracy measurements provided confident identification and quantitative analysis of imaged compounds. The linear correlation between concentration and grayscale of image in the range of 5 fmol/μ L to 1 pmol/μ L was obtained for all four peptides. Good sensitivity and excellent reproducibility were also achieved. The method expands the application of MALDI MSI from tissues to solutions.     

月见草油中溶剂残留测定方法的改进

An improved method for the analysis of residual solvent in EPO by gas chromatographic headspaceanalysis is presented.A better accuracy and a lower detectable limit of this method in comparing with thoseof GB 5009.37-85 were obtained.     

毛细管气相色谱法测定烷烯分离装置产物中烯烃及烷烃

Olefin and paraffin contents in products of Olex unit were determined by capillary gas chromatography,instead of mass spectrometry,as a routine assay method.The reproducibility of quantitation has also been evaluated and the results are satisfactory.     

Molecular electronegativity in density functional theory(Ⅷ)——Charge polarization modes in a closed system

Based on the density functional theory and the atom-bond electronegativity equalization model (ABEEM), a method is proposed to construct the softness matrix and to obtain the electron population normal modes (PNMs) for a closed system. Using this method the information about the bond charge polarization in a molecule can be obtained easily. The test calculation shows that the PNM obtained by this method includes all the modes about the bond charge polarization explicitly. And the bond charge polarization mode characterized by the biggest eigenvalue, which is the softest one of all modes related with chemical bonds, can describe the charge polarization process in a molecule as exquisitely as the corresponding ab initio method.     

Determination of metoprolol in rabbit blood using capillary electrophoresis with laser-induced fluorescence detection

This work described a sensitive method for determination of metoprolol in rabbit plasma.The method involved purification by ultrafiltration,derivatization with fluorescein isothiocyanate,determination by capillary electrophoresis(CE) coupled with laser-induced fluorescence(LIF) detector.Other components in plasma including a variety of amino acids and proteins did not interfere with the determination of metoprolol in experimental condition.The assay had a wide range(2.0-500 ng/mL) of linearity and a detection limit of 0.8 ng/mL.The intra- and inter-day precisions were satisfactory with relative standard deviation(RSD) less than 10.0%and accuracy within 10.0%.This method was successfully applied to pharmacokinetic study of metoprolol in rabbit blood.     

Simultaneous determination of flavonoids and anthraquinones in chrysanthemum by capillary electrophoresis with amperometry detection

<正>A high-performance capillary electrophoresis with amperometry detection method(CE-AD) has been developed for the analysis of flavonoids and anthraquinones(emodin,kaempferol,apigenin,luteolin and rhein) in chrysanthemum.Under optimum conditions,these five analytes were base-line separated within 17 min using a borate-phosphate running buffer(1.5×10~(-2) mol/L borate-3×10~(-2) mol/L phosphate running buffer,pH 9.0) at a working potential of +0.90 V(vs.SCE) and a separation voltage of 19 kV.The linear relationship between concentration and current response was obtained with detection limits(S/N = 3) ranging from 1.0×10~(-7) to 2.1×10~(-7) g/mL for all analytes.This proposed method was successfully used in the analysis of four kinds of chrysanthemum with relatively simple extraction procedures,the assay results were satisfactory.     

IDENTIFICATION OF PARTIAL MUTATIONAL SITES IN HUMAN MITOCHONDRIAL DNA IN THE CHINESE AND ITS SIGNIFICANCE

A simple method for the identification of mutational sites in human mitochondrial DNA (mtDNA) was described. It was based on the human Cambridge sequence as a relative standard sequence and a single base pair substitution in mtDNA as a unique mutational form. The partial mutational sites can be determined using this method which was characterized by combining the restriction mapping with the analysis for the table of human mtDNA potential mutational sites with rapidity and simplicity. In the meanwhile, six mtDNA mutational sites found in Chinese population were identified by means of this method.     

Discriminating against injectable fat emulsions with similar formulation based on water quenching fluorescent probe

The discrimination against nutritional fat emulsion injections was considered by imaging tools,which aims to elucidate the in vivo behaviors of nanoemulsions.In this study,20%nutritional fat emulsion injections were selected from different company including original and generic products.Meanwhile,a water quenching fluorescent probe(P2)was used to label them by an incubation method.The fluorescent intensity analysis of blood-borne fluorescence reveals rapid clearance of nanoemulsion in all groups,which shows'L'-type blood kinetic profiles.However,these kinetic parameters do not have significant difference.Following intravenous administration,the nanoemulsions in all groups concomitantly accumulated in organs of reticulo-endothelial system(RES),such as liver and spleen,and were cleared from body circulation mostly after 12 h.AUC(0-t)of organs from different groups showed dissimilar results in some organs.These intuitional results are of significance in understa nding the in vivo behaviors of nanoemulsions,which can provide a new way to discriminate against nutritional fat emulsions.     

HPLC with Diode-Array Detection for Determination of Leflunomide in Tablets

We have developed and validated a simple HPLC method for analysis of leflunomide in tablets. Method conditions were determined by assay of a photodegraded sample of leflunomide. Optimum chromatographic performance was obtained with a C₁₈ column and acetonitrile-water as mobile phase. Comparison of spectra recorded with a diode-array detector during elution of the leflunomide peak enabled determination of method specificity. The method is highly sensitive (detection limit 10 ng mL⁻¹) and robust to deliberate variation of the conditions (RSD of peak area < 2.0%). Precision and accuracy were adequate over the concentration range 10 to 100 μg mL⁻¹. These results show the proposed method is suitable for its intended use.     

Synthesis of Some Potential Antiangiogenic 1,3-Dihydro-l,3-dioxo-2H-isoindole Derivatives

Based on the structure-activity relationships of RGD-containing peptides, a series of 1,3-dihydro-l,3-dioxo-2H-isoindole derivatives were synthesized. All of them were first reported.Their structures were confirmed by spectral data and elemental analysis. Their ability to inhibit angiogenesis were evaluated in the chick embryo chorioallantoic membrane assay at -10^-5 mol/L.Compounds 5b and 5e displayed obviously antiangiogenic activity.     

Multiwavelength spectrophotometric determination of acidity constants of 1-（2-thiazolylazo）-2-naphthol in methanol-water mixtures

The acid-base properties of 1-(2-thiazolylazo)-2-naphthol (TAN) in mixtures of methanol-water at 25℃and an ionic strength of 0.1 mol/L are studied by a multi-wavelength spectrophotometric method.The acidity constants of all related equilibria are estimated using the whole spectral fitting of the collected data to an established factor analysis model DATAN program was used for determination of acidity constants.The corresponding pK_a values in methanol-water mixtures were determined.There is a linear relationship between acidity constants and the mole fraction of methanol in the solvent mixtures.     

PREPARATION OF V_2O_3 BY THERMAL DECOMPOSITION OF HYDRAZINE-CONTAINING VANADIUM SALT

A new method of preparing V_2O_3 by thermal decomposition from hydrazine-containing vanadium salt was described. The process was investigated by thermal analysis (TG and DSC) and the thermally decomposed product was studied by S.E.M., chemical analysis and X-ray diffraction. The result indicated that the product obtained in this way was V_2O_3.