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To evaluate several laboratory methods for the diagnosis and prediction of high risk baby developing allergic diseases. It also evaluats the severity and the treatment effects on allergic diseases . It recommend, the use of evidence-based medicine technique to improve the development of these diagnosis methods.
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Objective To explore the determination of dioxin in wastewater samples pretreated by solid phase microextraction(SPME). Methods The wasterwater samples were purified and enriched by SPME, then were determined with HRGC-HRMS for the concentration of dioxin in wastewater samples. Results The most suitable conditions of the pretreatment were 30 min microextraction at 45 ℃. The detection limit was 0.05 pg/?l. RSD was lower than 10%. The recovery rates were 99%-102%. The concentration of total dioxins in wastewater sample was 0.78 pg/?l. Conclusion The method of the determination of dioxins in wastewater by SPME was simple and quick, and presented a broad prospects for application.
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Objective To establish an accurate, rapid and practical method for determination of lead in whole blood by graphite furnace atomic absorption spectrometry. Methods It can improve the accuracy and precision of the method by digesting blood sample in nitric acid at constant 135℃, adding matrix to standard series, using matrix modifier and changing ashing temperature of the graphite furnace. Results The linear range, detection limit, mean recovery rate and combination coefficient of variation of the method were 0-50 ?g/L, 1.96 ?g/L, 92.2% and 6.5% respectively. Conclusion This method shows some advantages such as low background, little interference, simple, rapid, sensitive, repeatable and accurate.
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This article introduces a new method: the chemical-activated luciferase gene expression (CALUX)assay for determine of dioxin,which is based on biological properly of a genetically modified cell line.The published thesis reports that the contents of dioxins in a same sample abtained from the CALUX assay and the internationally recoganized standard method for determination of dioxin: high resolution gas chromatography-mass spectrometry(HRGC-MS)showed perfectly positive correlation and well repeatibility. The CALUX assay presents less amount-required sample,shorter determination cycle and less expense compared with HRGC-MS assay. The CALUX assay can be used as a rapid screen assay for determination of dioxin in a large number of samples,and will be widely applied in the survey of dioxin pollution in environment.
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Objective To establish a discoloring kinetic analysis method for determination of trace formaldehyde in textiles. Methods Based on the catalysis of formaldehyde on the discoloring reaction of bromophenol blue oxidized by potassium bromated in phosphoric acid medium,the contents of formaldehyde in textiles were determinated by spectrophotometry. The optimum condition and kinetic parammeters of the reaction were studied in detail. Results The optimum required volumes of reagents were 2.0,3.0,1.0 ml for H3PO4,KBrO3 and bromophenol blue respectively.The reaction was optimized at 85 ℃ for10 min.At working wave length of 430 nm,the linear range was 0.05-0.40 ?g/ml,the detection limit was 0.006 9 ?g/ml ,the recovery rate and RSD were 96%-106% and 2.9%-3.2% respectively. Conclusion This method was easy ,rapid and sensitive for the determination of trace formaldehyde in textiles.
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Objective To study the determination of chromium in human hair by spectrophotometry using starch as color agent. Methods The total chromium(Cr)in human hair was oxidized by (NH4?雪2S2O3 into Cr6+,which could oxidize KI to form I-3 in acid medium. I-3 reacted with starch to form a blue colored complex,which revealed the maximum absorption peak at 590 nm. Results The contents of Cr in human hair were 8.46-29.56 ?g/g.The lowest detection limit and linear range were 0.02 and 0.02-1.0 ?g/ml respectively.The coefficient of variation and standard material-added recovery rates were 3.3% and 94.8%-104.5% respectively. Conclusion This methods was rapid,accurate and convenient for the determination of chromium in human hair.
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Objective To study the effective methods for extraction of clenbuterol from biological material. Methods Clenbuterol in blood samples was extracted with 5 different methods,the extracts from various extraction methods were determined by gas chromatography-mass spectrometry(GC-MS?雪. The efficiency of 5 extraction methods was compared with each other. Results The standard curve showed good linear relationship with a range from 0.01-10.0 mg/L clenbuterol hydrochloride(r=0.999 9?雪. The detection limit was 0.005 mg/L. After adding 1.0 ?g/ml clenbuterol hydrochloride into blood sample,the blood sample was immersed and extracted in 0.01 mol/L HCl and absolute alcohol.The extracts were extracted by chloroform at pH value of 11. The average recovery and RSD of this method were 96.5% and 5.21% respectively(n=6?雪. Conclusion The method showed easy operation and reliable results ,it was suitable for determination of clenbuterol in biological material without deviation.
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Objective To study the determination of trace phenol in water using multi-wall carbon nanotubes(MWNT) film-coated glassy carbon electrode(GCE). Methods The contents of trace phenol in environmental water samples were measured by cyclic voltammetry and square wave voltammetry. The electrochemical behaviors of phenol on the MWNT-modified electrode were studied also. Results Phenol revealed a well-defined and sensitive oxidation peak with potential of 0.69 V on the MWNT-modified GCE in pH 7.0 phosphate buffer. The oxidation peak current of phenol on the MWNT-modified GCE increased significantly compared with that on a bare GCE. The linear range was 4.0?10-8 to 1.0?10-5 mol/L, and the detection limit was 1.0?10-8 mol/L. The relative standard deviation (RSD) of ten measurements was 5.2% for 5.0?10-7 mol/L phenol. Conclusion This proposed electrochemical techniques was suitable for the determination of trace levels of phenol in the environmental water samples.
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Objective To study the method for determination of pentachlorophenol(PCP) in water by headspace solid phase microextraction(SPME) gas chromatography. Methods Pentachlorophenol in water samples was extracted using optimized SPME technology, separated by SE30 chromatographic column and the content of pentachlorophenol in water was determined by electron capture detector (ECD) under the conditions: adjusting water samples to pH 2.0, to maintain an agitating equilibrium concentrations at 60 ℃ for 40 min, headspace absorption for 10 min using extraction head holding polyacrylic ester-coated microfiber (0.83 ?m in thickness), desorption at 280 ℃ for 3 min. Results The detection limit of the method was 0.13 ?g/L. The correlation coefficient r=0.999 was noticed in range of pentachlorophenol concentrations 0-12 ?g/L. When adding standard material of pentachlorophenol at concentrations of 1 ?g/L, 6 ?g/L, 10 ?g/L, the recovery rates were 88.9%-105.0%, 88.9%-102.8% and 98.0%-99.5% respectively and the RSD were 4.9%-8.4%, 3.1%-8.5% and 4.0%-5.4%(n=6)respectively. Conclusion The method was simple, sensitive, stable and without solvent pollution, which was an ideal method for determination of pentachlorophenol in water.
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Objective To ensure the reliability and accuracy of the data of the determination of iron in water. Methods The contents of iron in 177 water samples including well water, river water, steam water and tap water were determined by 1,10-phenanthroline spectrophotometry and atomic spectrophotometry.The effects of homogenous state and storage condition of water samples on the results of assay were analyzed ,the reason for the excessive iron in water samples was analyzed also. Results The rates of exceeding the standard were 5.08% for water samples untreated by well mixing during sampling and 31.64% for those treated by well mixing,there was significant difference between them(?2=39.87,P
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Objective To establish a simple,rapid,accurate and sensitive method for determination of free toluene diisocyanate in paint.Method The samples were diluted by acetone and separated using GC,25%SE-30column.The contents of free toluene diisocyanate in the samples of paint were analysed by gas chromatography.The qualitative and the quantitative analyses were carried out based on the retention time and peak height or peak area respectively.Re -sults The linear range of the method was0.000～0.025%with r=0.9997.The RSD was in the range of0.08～0.75%and the recovery rates ranged95.0～106.7%.Conclusion The method was simple,rapid and accurate,which was suit-able for the determination of free toluene diisocyanate in paint.