Preparation and application of proficiency testing sample of myclobutanil and procymidone in apple powder / 上海预防医学

ObjectiveTo prepare pesticide residues in fruit matrix samples that meet the requirements of homogeneity and stability for the proficiency test. MethodsThe pollution-free apple was selected as the main raw material to prepare the pesticide residue proficiency test samples of myclobutanil and procymidone， and to evaluate the homogeneity and stability. The results of the proficiency test were assessed using robust analysis and Ζ value. ResultsThe homogeneity and stability of the reference materials met the relevant requirements. Among 109 laboratories participated in the proficiency testing， 107 （98.2%） laboratories had satisfactory results. Suspicious test results were reported only in two laboratories， one laboratory for each of the two assessment items. ConclusionAn apple powder matrix sample with pesticide residues is successfully prepared for proficiency test， and could provide an evaluation tool for pesticide residue testing laboratories.

Establishment and optimization of inductively coupled plasma mass spectrometry (ICP-MS) for the determination of aluminum residues / 中国输血杂志

【Objective】 To establish and optimize a method for the determination of aluminum (Al) residue by inductively coupled plasma mass spectrometry (ICP-MS). 【Methods】 Nitric acid solution was used to treat samples and standards. The concentration of nitric acid solution and equipment parameters were optimized, and the specificity, linearity, repeatability, accuracy, detection limit, quantitative limit and intermediate precision of the optimized detection method were investigated to confirm whether it was suitable for the determination of Al residue in human serum albumin. 【Results】 The concentration of nitric acid was 5%, and digest time was 4 h. The equipment condition of ICP-MS was as follows: RF power: 1600 W, sampling depth: 10 mm, atomizer / carrier gas flow rate: 1.0 L/ min, compensation flow rate: 0.5 L/ min, experimental mode: standard mode, integration time: 0.2 s, data acquisition: 3 times. Specificity: The recoveries of Al: 92% (high concentration, RSD=3.5%), 98% (low concentration, RSD=4.9%). Linearity: In the range of (0~40) μg/L, the correlation coefficient between concentration and optical energy signal (CPS) of standard / sample were higher than 0.999 0. Accuracy/ Repeatability: The recoveries of sample (3 concentration): 108% (RSD=4.7%), 110% (RSD=4.9%) and 110% (RSD=2.8%). The detection limit was 0.006 μg/L, and the quantitation limit was 0.019 μg/L. Intermediate precision: personnel factor and date factor, P>0.05, RSD (12 times)=2%. Comparison between ICP-MS and atomic absorption spectrometry (AAS): the deviation between ICP-MS and AAS was 8%, and that of samples was 3%, with no significant difference noticed between the two methods. 【Conclusion】 After optimization, ICP-MS method has shown good performance in terms of specificity, linearity, repeatability, accuracy, detection limit, quantitative limit and intermediate precision, and is suitable for the determination of Al residue in human albumin products of our company.

Determination of six heavy metals in peanuts using microwave-assisted digestion-inductively coupled plasma mass spectrometry with an octopole reaction system / 预防医学

Objective @#To establish a microwave-assisted digestion-inductively coupled plasma mass spectrometry (ICP-MS) with an octopole reaction system for simultaneous determination of six heavy metals in peanuts, including Cr, Ni, As, Cd, Pb, Hg. @*Methods @#Peanut samples were shelled and crushed evenly, and 0.350 0 g was accurately weighed and digested with 5 mL nitric acid and 1 mL hydrogen peroxide in a digestion tank. Following microwave-assisted digestion, pure water was used to quantify the samples, and internal standards and an octopole reaction system were used to remove the interference. Then, the contents of six heavy metals were determined in peanuts by ICP-MS. The accuracy and precision of ICP-MS were evaluated using national criteria ( GBW 10013 and GBW 10044 ) and spike-and-recovery testing. @*Results @#The six heavy metals showed good linearity at the selected linear range ( r≥0.999 8 ). The detection limits of ICP-MS ranged from 0.001 4 to 0.023 8 ng/mL, and the spike-and-recovery rates ranged from 94.7% to 98.8%, with the relative standard deviations ranging from 0.7% to 3.6%. In addition, the determination results of the standard reference materials were all within the normal reference range. The detection of six heavy metals was 100.0% in 60 peanut samples, and the contents of six heavy metals were all low.@*Conclusion @#The established ICP-MS assay is feasible for simultaneous determination of multiple heavy metals in peanuts.

Determination of fluoxetine ，norfluoxetine and sertraline concentration in human placental perfusate and their placental permeability by UFLC-MS/MS / 中国药房

OBJECTIVE To establish t he method for determining the concentrations of fluoxetine ，norfluoxetine and sertraline in human placental perfusate method and their placental permeability. METHODS Using glyburide as internal standard ，the samples were pretreated by protein precipitation method and detected by ultra-fast liquid chromatograph-mass spectrometer/mass spectrometer （UFLC-MS/MS）. The determination was performed on Synergi TM Hydro-RP 80A LC column with mobile phase consisted of water （containing 0.1％ formic acid ）-acetonitrile（containing 0.1％ formic acid ）at the flow rate of 0.70 mL/min，with a gradient elution. The column temperature was set at 40 ℃，and sample size was 5 μL. Detection was performed with electrospray ionization source in multipl e reaction monitoring mode . The ion pairs for quantitative analysis we re m/z 309.9→148.1（fluoxetine），m/z 296.0→134.4 （-167）， （norfluoxetine），m/z 306.1→159.0 （sertraline），m/z 493.9→ No.2018FE001（-207），（internal standard ）. The perfusion model of singal placenta under bidrectional cardiopulmonary bypass was established. Fluoxetine （160 ng/mL），norfluoxetine（160 ng/mL）， sertraline（100 ng/mL）and antipyrine （positive control ，ng/mL）were added into the maternal perfusate. The concen- 65324888 trations of fluoxe tine， norfluoxetine and sertrali ne were measured by above UFLC-MS/MS at 0，10，20，30，45，60，90，120，150 and 180 min of circulation ，and the placental permeability was calculated. RESULTS The linear range of fluoxetine ，norfluoxetine and sertraline were 5.00-500 ng/mL（all r＞ 0.990），and the lower limits of quantification were all 5.00 ng/mL. The RSDs of intra-day and inter-day were all less than 14.0％， and relative error ranged －9.6％ to 14.7％. The relative error of stability test was －4.0％ to 11.0％；the residual effect ，extraction method and matrix effect did not affect the quantitative analysis of the substance to be tested. Totally 31 perfusion model of human placenta under cardiopulmonary bypass were successfully established ，including 15 fluoxetine and norfluoxetine perfusion ，10 sertraline perfusion and 6 antipyrine perfusion. After 3 hours of perfusion ，the average placental permeability of fluoxetine ， norfluoxetine and sertraline were （8.74 ± 1.67）％ ，（10.70 ± 4.81）％ ，（5.90 ± 1.25）％ ，respectively. CONCLUSIONS The established UPLC-MS/MS is simple ，sensitive and accurate. It can be used for determination of fluoxetine ，norfluoxetine and sertraline in human placental perfusate. Fluoxetine ，norfluoxetine and sertraline can pass through the placenta ，but sertraline has a lower placental permeability.

Supramolecular Solvent Extraction-Gas Chromatography-Tandem Mass Spectrometry for Detection of Benzodiazepines in Urines / 法医学杂志

Objective To establish a method using supramolecular solvent and gas chromatography-tandem mass spectrometry （GC-MS/MS） to analyze 9 benzodiazepines in urines. Methods Urine samples containing 9 benzodiazepines reference substance were subjected to liquid-liquid extractions with supramolecular solvent, which consisted of tetrahydrofuran and 1-hexanol. The solvent layer was evaporated to dryness by stream of nitrogen. The residue was reconstituted with methanol, and GC-MS/MS analysis was performed on it. The way of data collection was multiple reaction monitoring （MRM） mode; internal standard method was employed for quantification. Results In urine samples, when the range of mass concentration was 1-100 ng/mL for diazepam, midazolam, flunitrazepam and clozapine, 5-100 ng/mL for lorazepam and alprazolam, 2-100 ng/mL for nitrazepam and clonazepam, and 0.2-100 ng/mL for estazolam, respectively, good linearities were obtained, correlation coefficients were 0.999 1-0.999 9, the lower limits of the quantifications ranged from 0.2 to 5 ng/mL, the extraction recovery rates were 81.12%-99.52%. The intra-day precision ［relative standard deviation （RSD）］ and accuracy （bias） were lower than 9.86% and 9.51%, respectively; the inter-day precision （RSD） and accuracy （bias） were lower than 8.74% and 9.98%, respectively. Nine drugs in urine samples showed good stability at ambient temperature and -20 ℃ within 15 days. The mass concentrations of alprazolam in urine samples obtained from 8 volunteers who took alprazolam tablets orally within 8-72 h after ingestions ranged from 6.54 to 88.28 ng/mL. Conclusion The supramolecular solvent extraction GC-MS/MS method for analysis of 9 benzodiazepines in urines provided by this study is simple, fast, accurate and sensitive, which can provide technical support for monitoring of poisoning by benzodiazepines for clinical treatment and judicial identification.

How to identify “Material basis–Quality markers” more accurately in Chinese herbal medicines from modern chromatography-mass spectrometry data-sets: Opportunities and challenges of chemometric tools / 中草药·英文版

Modern chromatography - mass spectrometer (MS) technology is an essential weapon in the exploration of traditional Chinese medicines (TCMs) which is based on the “effectiveness-material basis-quality markers (Q-markers)”. Nevertheless, the hardware bottleneck and irregular operation will limit the accuracy and comprehensiveness of test results. Chemometrics was thereby used to solve the existing problems: 1) The method of ‘design-modeling-optimization’ can be adopted to solve the multi-factor and multi-level problems in sample preparation/ parameter setting; 2) The approaches of signal processing can be used to calibrate the deviation from retention time (rt) dimension and mass-to-charge ratio (m/z) dimension in different types of instruments; 3) The methods of multivariate calibration and multivariate resolution can be utilized to analyze the co-eluting peaks in complex samples. When the researchers need to capture essential information on raw data sets extracting the higher level of information on essential features, 1) The significant components which affects the drug properties/efficacy can be find by the pattern recognition and variable selection; 2) Fingerprint-efficacy modeling is explored to clarify the material basis, or to screen out the Q-markers of biological significance; 3) Chemometric tools can apply to integrate chemical (metabolic) fingerprints with network pharmacology, bioinformatics, omics and others from a multi-level perspective. Under these programs, the qualitative/quantitative works will achieve in chemical (metabolic) fingerprint and metabolic trajectories, which leads to an accurate reflection of “material basis and Q-markers” in TCMs. Likewise, an in-depth hidden information can be disclosed, so that the components of drug properties/efficacy will be found. More importantly, multidimensional data can be integrated with fingerprints to acquire more hidden information.

Determination of volatile organic compounds in air using portable gas chromatography-mass spectrometry / 中国职业医学

OBJECTIVE: To explore a method for detecting volatile organic compounds(VOCs) in air by a portable gas chromatography-mass spectrometer(GC-MS). METHODS: A portable GC-MS hand-held probe was used for sampling and detection. All effluent components were qualitatively analyzed by the standard spectral library of the United State National Institute of Standards and Technology. The percentage of peak area of the component was calculated by normalization method. The static distribution method was adopted in the semi-quantitative and quantitative analysis using nitrogen as the diluting gas to prepare different mass concentration of 13 kinds of VOCs in the mixed standard gas. The retention time and characteristic ions were used for qualitative analysis, and the quantitated full scanning mode was used for quantitative analysis.RESULTS: The minimum detected mass concentration of the 13 chemical harmful factors was 0.02-0.10 mg/m~3, and the minimum quantitative mass concentration was 0.07-0.38 mg/m~3. The recovery rate was 84.76%-116.56%, and the within-and between-run relative standard deviations were 4.10%-12.50% and 8.17%-14.36%, respectively. CONCLUSION: The portable GC-MS instrument could be used for qualitative alalysis, peak area percentage determination, semi-quantitative and quantitative analysis of VOCs in the workplace air or sudden chemical poisoning accidents.

The Interaction between Aptamer and Beclomethasone Based on High Resolution Mass Spectrometry and Molecular Docking / 中国生物化学与分子生物学报

Beclomethasone is an effective glucocorticoid, and beclomethasone-aptamer is a short single-stranded DNA with affinity and specificity to beclomethasone. The interaction between them is still unclear. The study of the interaction between aptamers and beclomethasone has a certain significance for the application of aptamers. In this study, high-resolution Fourier transform ion cyclotron resonance mass spectrometer (FT-MS) and molecular docking simulation technology were used to study the interaction between aptamer and beclomethasone. Firstly, under the optimized conditions of high-resolution mass spectrometry parameters, the complex of aptamer and beclomethasone was detected by the negative ion scanning mode with the electrospray ion source. Based on the results of high-resolution mass spectrometry, most of the compounds were -8-valent ions, and their dissociation constant K

Chemical Composition Analysis of Antibacterial and Anti-inflammatory Functions of Volatile Oils from Pelargonium graveolens L'Herit / 中国生物化学与分子生物学报

The components of volatile oils are generally complex, and they often have the functions of divergent dissolving surface, insecticidal and antibacterial. However, there are few reports on bacteriostasis, anti-inflammation and antioxidation roles of volatile oils of Pelargonium graveolens L'Herit. The volatile oil of Pelargonium graveolens L’Herit. was extracted by steam distillation, and GC-MS and peak area normalization analysis showed that it mainly contained 30 compounds, and the identified components accounted for 90.26% of the total peak area. The volatile oil of Pelargonium graveolens L'Herit. has a certain inhibitory effect on Candida albicans and Staphylococcus aureus, especially on Candida albicans. The diameter of the bacteriostatic zone is 15.55±1.53 mm by using the oxford cup method. Dexamethasone and low, middle and high doses of volatile oils of Pelargonium graveolens L'Herit. were given after the RAW264. 7 cell inflammatory model and was induced by lipopolysaccharide (LPS = 10.0 μg/mL). ELISA assays showed that it could effectively reduce the expression of IL-1β and TNF-α in inflammatory cells, and the effect of high doses was similar to that of IL-1β and TNF-α in the dexamethasone group. GC-MS was successfully used to determine and identify the chemical constituents of volatile oils from Pelargonium graveolens L'Herit. in this study. We show that the volatile oil of Pelargonium graveolens L'Herit. had certain bacteriostatic activity and effectively reduces the secretion of IL-1β and TNF-α by inflammatory cells. It provides an experimental basis for the development and utilization of volatile oils from Pelargonium graveolens L'Herit.

The Adaptational Regulation Mechanism of the Apoptosis in Aged Rats’ Striatum in Response to Regular Aerobic Exercise Based on Carbonylation Proteomics / 中国生物化学与分子生物学报

This paper investigated the effects of regular aerobic exercise on protein oxidative stress and apoptosis in aging rat striatum, and further analyzed its target proteins and mechanism based on differential carbonylation proteomics. Totally 24 specific pathogen-free (SPF) 23-month-old male Sprague-Dawley (SD) rats were randomly divided into aged sedentary control group (Con-SED, n = 12) and aged regular aerobic exercise runner group (Aero-EXE, n = 12). The medium intensity of regular aerobic exercise model: The intensity of maximum oxygen consumption (VO

Antagonistic activity of volatile metabolites from Trichoderma asperellum / 生物工程学报

Trichoderma spp. is a kind of filamentous fungi with important biocontrol value. Twelve strains of Trichoderma spp. were isolated from the soils of different types of crops in Shaoxing, Zhejiang and Foshan, Guangdong. The antagonistic resistance to Fusarium oxysporum was compared by plate confrontation test. The further analysis of volatile secondary metabolites for two strains were carried out using HS-SPME-GC-MS analysis. The results showed that T. asperellum ZJSX5003 and GDFS1009 had fast growth ability, and the inhibition effects on F. oxysporum were 73% and 74% respectively. Six identical volatile metabolites were detected as follows 2-Methyl-1-propanol, 3-Methyl-1-butanol, 3-Methyl-3-buten-1-ol, Acetyl methyl carbinol, Butane-2,3-diol and 6-n-pentyl-2H-pyran-2-one (6-PAP). Among them, 6-PAP was validated to have a higher inhibitory effect on F. oxysporum in vitro. This study will provide basis for the development of biocontrol agents with metabolites of Trichoderma, such as 6-PAP.

Investigation of chemical profile of bile acids and determination of them in cultured Bovis Calculus with UPLC-QDA / 中国中药杂志

In this study, 10 batches of samples of cultured Bovis Calculus(cow-bezoar) were determined for the investigation of chemical profile of bile acids with the UPLC-QDA method established. The results showed that nine common bile acids, cholic acid(CA), deoxycholic acid(DCA), chenodeoxycholic acid(CDCA), taurocholic acid(TCA), taurodeoxycholic acid(TDCA), taurochenodeoxycholic acid(TCDCA), glycocholic acid(GCA), glycodeoxycholic acid(GDCA) and glycochenodeoxycholic acid(GCDCA), were founded in samples and 7 bile acids were quantified except GDCA and GCDCA. In these samples, unconjugated bile acids, the major type of bile acids, accounted for more than 97% of all types of bile acids. As for unconjugated bile acids, CA was the most major bile acid in cultured cow-bezoar and it was about twice as much as DCA. The relative low-cost method established in the current study is accurate, rapid and sensitive, which is suitable for the studies of other drugs from animal bile.

Calibration and performance verification of gas chromatography-mass spectrometer for urine organic acid detection after annual maintenance / 临床检验杂志

Objective@#To establish a method of calibration and performance verification of the GCMS-QP 2010 Ultra gas chromatography-mass spectrometer for urine organic acid detection after annual maintenance, so as to ensure that the performance of the detection system can continuously meet the detection needs. @*Methods@#According to the requirements of the equipment manufacturer and the Calibration Specifications for Benchtop Gas Chromatography-Mass Spectrometer, the gas chromatography-mass spectrometer was calibrated after annual maintenance. According to the CNAS-CL02-A003 Guidance on the Application of Accreditation Criteria for the Medical Laboratory Quality and Competence in the Field of Clinical Chemistry, the analytical performance of the maintained gas chromatography-mass spectrometer was validated. @*Results@#The calibration results of quality range, quality accuracy, resolution, signal-to-noise ratio and repeatability were all met the requirements. The detection results of internal quality control materials were under control, and the results of retained samples kept unchanged. @*Conclusion@#The calibration and performance verification method of the gas chromatography-mass spectrometer for urine organic acid detection after annual maintenance is established successfully, which is of importance for providing accurate and reliable results of urine organic acid.

Simultaneous detection of four kinds of methyl acrylate compounds in workplace air by a portable GC-MS technique / 中国职业医学

OBJECTIVE: To establish a method for simultaneously detecting methyl methacrylate, ethyl methacrylate, n-propyl methacrylate and butyl methacrylate in workplace air by a portable gas chromatography-mass spectrometer(GC-MS) technique. METHODS: The portable GC-MS hand-held probe was used for sampling and detection. Samples were separated with DB-5 rapid chromatographic column in order to maintain retention time and characteristics of the ions, and quantified by standard curve method. RESULTS: The linear correlation of this method was higher than 0.999 0. The minimum detection concentration was 0.03-0.06 mg/m~3, and the minimum quantitation concentration was 0.10-0.20 mg/m~3. The standard recovery rate was 82.22%-91.24%. The within-run and the between-run relative standard deviation were 7.67%-14.63% and 10.40%-13.79% respectively. CONCLUSION: The portable GC-MS technique could be used for qualitative and quantitative detection of above-mentioned four methylacrylate compounds in workplace air.

Effect of diesel exhaust exposure on 8-hydroxy-2' deoxyguanosine level in biological samples of automobile manufacturing workers / 中国职业医学

OBJECTIVE: To investigate the feasibility of using 8-hydroxy-2'deoxyguanosine(8-OHdG) in blood and urine samples as biomarkers for the evaluation of human DNA oxidative damage caused by diesel exhaust(DE). METHODS: A convenient sampling method was used to select 56 male workers exposed to DE in a car manufacturing factory as exposure group, and 52 male workers without exposure to DE were selected as the control group.Urine samples and blood samples were collected from workers in the 2 groups 8 hours after work, and the levels of 8-OHdG in urine and plasma were measured by ultra-high performance liquid chromatography tandem mass spectrometer. RESULTS: The median level of urinary 8-OHdG in the exposure group was higher than that of control group(2.54 vs 2.03 μg/g Cr, P<0.05). The median levels of plasma 8-OHdG in the exposure group and control group showed no statistical significance(32.20 vs 31.40 ng/L, P>0.05). CONCLUSION: The urinary 8-OHdG can be used as a biomarker for evaluating the oxidative damage induced by DE exposure.

Serum metabonomics study in 66 patients with gastric cancer by liquid chromatography-mass spectrometry / 中华消化杂志

Objective To detect whether patients with gastric cancer had unique serum metabolomic characteristics by liquid chromatography-mass spectrometry (LC-MS) metabolomic analysis,and to screen potential markers for early gastric cancer and to preliminarily explore the related metabolic pathways.Methods At the First Affiliated Hospital of Soochow University,66 patients with gastric cancer and 44 patients with benign gastric disease from July,2017 to January,2018 were enrolled,and 50 healthy subjects served as controls.Twenty-five patients with gastric cancer at stage Ⅰ and Ⅱ and 25 patients with gastric cancer at stage Ⅲ and Ⅳ were selected from the 66 patients with gastric cancer,and 25 subjects were also selected from 50 healthy controls.The plasma small molecule metabolites of patients with gastric cancer and benign gastric disease and healthy controls were detected by LC-MS method.Multivariate logistic regression analysis was used to establish and validate the principal component analysis (PCA) model and partial least squares-discriminant analysis (PLS-DA) model and screen the differential metabolites.The receiver operating characteristic curve analysis was used to evaluated the clinical efficacy of differential metabolites.Results PCA and PLS-DA models showed that gastric cancer had a obviously specific metabolites profile,the profile of benign gastric disease overlapped with that of gastric cancer and healthy controls.The results of multivariate logistic regression analysis confirmed that four metabolites including isoleucine,benzophenone,sphingosine-1-phosphate and galactopyranose set could be used to establish an optimal diagnostic model.The area under the curve (AUC)(95％ confidence interval (CI)) was 0.963 (0.930 to 0.997),and the best cut off value,sensitivity and specificity were 0.871,93.1％ and 94.0％,respectively.Meanwhile,patients with gastric cancer at stage Ⅰ + Ⅱ and stage Ⅲ + Ⅳ had a distinct clustering trend compared with the control group.In the serum of patients with gastric cancer at stage Ⅰ + Ⅱ and stage Ⅲ + Ⅳ,a total of 24 differential metabolites were identified,theconcentration of five of which including lysine,carnitine,benzenesulfonamide,arginine and docosahexaenoic acid ethyl ester,increased along with the progression of gastric cancer.Pipecolic acid and kynurenine might served as biomarkers for early and mid gastric cancer (stage [+ Ⅱ) screening.Conclusions LC-MS metabolomic effectively confirm the unique changes of serum metabolites in patients with gastric cancer.The screened differential metabolites have potential clinical application value for predicting the risk of gastric cancer.

Comparison of chemical constituents of wild silkworm cocoon and domestic silkworm cocoon by UHPLC-MS technology / 生物工程学报

Identifying and comparing the chemical constituents of wild silkworm cocoon and silkworm cocoon is of great significance for understanding the domestication of silkworm. In this study, we used high temperature and high pressure and methanol-water system to extract cocoon chemical constituents. We used UHPLC-MS to identify and compare cocoon chemical constituents of wild silkworm and domestic silkworm Dazao and Haoyue strains. The cocoon metabolic fingerprints of wild silkworm and domestic silkworm Dazao and Haoyue strains were obtained by using the UHPLC-MS in the positive ion mode and negative ion mode. By annotation, we found that cocoon chemical compounds with high abundances contained amino acids, flavonoids, alkaloids, terpenes, organic acids, and lignans. PLS-DA showed that the cocoon components were significantly different among the wild silkworm and two domestic silkworm strains Dazao and Haoyue. Proline, leucine/isoleucine and phenylalanine showed significantly higher abundances in the cocoon of domestic silkworm Dazao strain than in those of wild silkworm and domestic silkworm Haoyue strain. The flavonoid secondary metabolites are abundant in the Dazao cocoon, including quercetin, isoquercetin, quercetin 3-O-sophoroside, quercetin-3-O-α-L-rhamnoside, quercetin-3-O- rutinoside, and kaempferol. The other secondary metabolites, alkaloids, terpenes and lignans, showed higher abundances in the wild silkworm cocoon than in the domestic silkworm cocoon, including neurine, candicine, pilocarpidine, artemisiifolin, eupassopin, and eudesobovatol. By exposing cocoons to UV light and observing the green fluorescence of flavonoids, we found that Dazao cocoon had the most flavonoids, and Haoyue cocoon had least flavonoids and wild silkworm cocoon had mediate flavonoids. Alkaloids and organic acids are good anti-insect and antimicrobial agents, which have high abundance in the wild silkworm cocoon and could enhance the defense ability of wild silkworm cocoon. Flavonoids are abundant in the cocoon of domestic silkworm Dazao strain, which the main factors are leading to the yellow-green cocoon of Dazao.

Preparation of Rat Spinal Synaptosome and Qualitative and Quantitative Test of Neurotransmitters / 中国康复理论与实践

Objective:To prepare rat spinal synaptosomes, and to conduct qualitative and quantitative analysis of various neurotransmitters in rat spinal synaptosomes to explore the physiological activities. Methods:Rat spinal synaptosomes were prepared by discontinuous Percoll density gradient centrifugation and their morphology and structure were observed under transmission electron microscopy. The properties and content of neurotransmitters in rat spinal synaptosomes were determined by ultra performance liquid chromatography-tandem mass spectrometry. Results:Under the experimental conditions, rat spinal synaptosomes were found to contain dopamine, norepinephrine, serotonin, homovanillic acid, 3,4-dihydroxybenzene, 5-hydroxyindoleacetic acid, methoxytyramine, tryptophan, γ-aminobutyric acid, kynurenine, 3-hydroxy kynurenine and 3-hydroxy-2-aminobenzoic acid, and so on. The corresponding neurotransmitter contents were detected, and the corresponding linear relationship and correlation coefficient were obtained. Conclusion:Discontinuous Percoll density gradient centrifugation could prepare rat spinal synaptosomes and detect neurotransmitters and their contents in rat spinal synaptosomes.

Detecting 12 elements in human biological samples by ICP-MS method / 中国职业医学

OBJECTIVE: To establish a method for detecting the contents of 12 toxic elements such as beryllium,vanadium and thallium in human whole blood,urine and hair by inductively coupled plasma-mass spectrometry( ICP-MS).METHODS: Whole blood( 0.25 mL) and urine( 10.00 mL) were diluted 20 times into suspension by 0.1% TritonX-100 + 0.5% nitric acid,and analyzed by ICP-MS.The hair( 0.20 g) was mixed with nitric acid and digested by microwave,then made up to 10.00 mL with purified water.The analysis was performed by ICP-MS.RESULTS: The linear correlation coefficients of all the 12 elements,such as beryllium,vanadium,chromium,manganese,cobalt,nickel,arsenic,cadmium,tin,antimony,tellurium and lead were≥0.999 5.The detection limit for whole blood and urine was 0.097-1.995 μg/L,and the detection limit for hair was 0.001-0.012 μg/g.The recovery rates for whole blood,urine and hair were 92.3%-105.0%,93.7%-115.5% and 92.5%-111.0%,respectively.The within-run relative standard deviation( RSD) were 0.7%-5.8%,0.8%-4.6% and 2.2%-8.4%,respectively; the between-run RSD were 1.6%-7.1%,3.5%-7.5% and 2.8%-8.8%,respectively.CONCLUSION: This method has good accuracy,high sensitivity and good precision,which is suitable for rapid screening for various elements in human biological samples.

Rapid Detection of Trace Volatile Organic Compounds By Electric Driven Cryo-Trap Movable Mass Spectrometer / 分析化学

An electric driven cryo-trap enrichment apparatus for the movable mass spectrometer was designed to realize rapid and automatic detection of trace volatile organic compounds (VOCs) in the atmosphere. Compared with traditional cryo-trap with refrigerant,the lowest temperature of cryocooler was down to-196℃, and it was easy to carry due to its small size, light weight and refrigerant-free. Cryo-trap combined with time-of-flight mass spectrometer was used to analyze benzene,toluene and xylene,and the result showed that the signal strength of benzene,toluene and xylene,with the cryo-trap enrichment,was improved by 212-fold, 254-fold and 242-fold,and the recoveries reached 98%,87% and 87%,respectively. The analytical time for single sample was only 14 min. The electric driven cryo-trap combined with on-line mass spectrometer was used to detect 39 kinds of VOCs listed in TO-14 method of EPA and ambient air, and the sensitivity of the newly designed instrument was better than the threshold of national indoor VOCs. The combination of electric driven cryo-trap and time-of-flight mass spectrometer could be used for rapid enrichment and monitoring of trace VOCs in the atmosphere and indoor air, showing great potential in in-site measurement and real-time monitoring of volatile organic pollutants.