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Sysmex系列4台不同型号全自动血液分析仪结果比对分析 被引量:3
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作者 刘英杰 于雅宁 曲永玲 《医学检验与临床》 2014年第2期42-45,共4页
目的:通过Sysmex系列4台不同型号全自动血液分析仪对同一全血标本进行检测,了解每台仪器检测结果的准确性和一致性。方法:选用参加室间质评而且成绩优秀的仪器XT-2000i为参比仪器,其他仪器为比对仪器,其结果以美国临床实验室修正... 目的:通过Sysmex系列4台不同型号全自动血液分析仪对同一全血标本进行检测,了解每台仪器检测结果的准确性和一致性。方法:选用参加室间质评而且成绩优秀的仪器XT-2000i为参比仪器,其他仪器为比对仪器,其结果以美国临床实验室修正法案(CLIA’88)规定的室间质量评价允许误差的1/2为标准进行比较分析,即白细胞计数(WBC)&#177;7.50%、红细胞计数(RBC)&#177;3.00%、血红蛋白测定(HGB)&#177;3.50%、红细胞比容(HCT)&#177;3.00%、血小板计数(PLT)&#177;12.50%。结果:通过校准与比对,各台仪器准确性和一致性良好。结论:定期对我科4台全自动血液分析仪进行比对和校准,保证检测结果的准确性和一致性。 展开更多
关键词 血液分析仪 比对分析 相对偏差%
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Optimization of Chromatographic Conditions for Detecting Ellagic Acid in Pomegranate Peels Using HPLC Method 被引量:3
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作者 夏小龙 彭蓉 +3 位作者 李树垠 李端阳 干霞 白琦 《Agricultural Science & Technology》 CAS 2012年第11期2400-2403,共4页
[Objective] This study aimed to optimize the chromatographic conditions for detecting ellagic acid in pomegranate peels using HPLC method. [Method] By using 0.2 mg/ml ellagic acid standard solution, on the basis of si... [Objective] This study aimed to optimize the chromatographic conditions for detecting ellagic acid in pomegranate peels using HPLC method. [Method] By using 0.2 mg/ml ellagic acid standard solution, on the basis of single-factor experiment and orthogonal experiment, chromatographic conditions (mobile phase ratio, flow rate, col- umn temperature) for detecting ellagic acid using HPLC were optimized. Based on the optimal chromatographic conditions, the ellagic acid content in experimental pomegranate peels was determined. [Resull] The optimal chromatographic conditions for detecting ellagic acid in pomegranate peels using HPLC method are: 1.2% phos- phoric acid:acetonitrile=85:15, column temperature of 35 ℃, and flow rate of 1.0 ml/min. The linear regression equation of ellagic acid is: y=2.9e+0.6x+4.4e+5 (FF=9 999). Ac- cording to the standard addition recovery test, the average recovery rate of ellagic acid is 98.20%, and RSD is 0.60%. Under above optimized chromatographic condi- tions, ellagic acid can be well separated from other interfering components in pomegranate peels, with shorter peak time and ideal effect, which is convenient for the detection in production practices. [Conclusion] This study laid the foundation for detecting ellagic acid in pomegranate peels using HPLC method. 展开更多
关键词 Pomegranate peel Etlagic acid DETECTION HPLC
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Determination of Trace Elements in Potatoes by Flame Atomic Absorption Spectrometry
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作者 王宁芳 《Agricultural Science & Technology》 CAS 2014年第5期716-717,723,共3页
[Objective] This study aimed to analyze the contents of trace elements in potatoes from different production areas in Qinghai Province. [Method] By flame atomic absorption spectrometry (FAAS), the contents of variou... [Objective] This study aimed to analyze the contents of trace elements in potatoes from different production areas in Qinghai Province. [Method] By flame atomic absorption spectrometry (FAAS), the contents of various trace elements in potatoes were determined. [Result] Potatoes contain abundant trace elements such as Cu, Zn, Fe, Mn, Ca, K and Mg. To be specific, the contents of Ca, K and Mg were relatively high. [Conclusion] By using FAAS, the relative standard deviation was 1.17%-2.75% and the recovery rate was 97%-99.5%, indicating accurate and reli-able results with high precision. 展开更多
关键词 POTATO Flame atomic absorption spectrometry Trace elements Relative deviation PRECISION
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Determination of Lignin in Marine Sediment Using Alkaline Cupric Oxide Oxidation-Solid Phase Extraction-on-Column Derivatization-Gas Chromatography 被引量:10
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作者 ZHANG Ting LI Xianguo +3 位作者 SUN Shuwen LAN Haiqing DU Peirui WANG Min 《Journal of Ocean University of China》 SCIE CAS 2013年第1期63-69,共7页
Lignin serves as one of the most important molecular fossils for tracing Terrestrial Organic Matters (TOMs) in marine environment. Extraction and derivatization of lignin oxidation products (LOPs) are crucial for ... Lignin serves as one of the most important molecular fossils for tracing Terrestrial Organic Matters (TOMs) in marine environment. Extraction and derivatization of lignin oxidation products (LOPs) are crucial for accurate quantification of lignin in marine sediment. Here we report a modification of the conventional alkaline cupric oxide (CuO) oxidation method, the modification consisting in a solid phase extraction (SPE) and a novel on-column derivatization being employed for better efficiency and reproducibility. In spiking blanks, recoveries with SPE for the LOPs are between 77.84% and 99.57% with relative standard deviations (RSDs) ranging from 0.57% to 8.04% (n=3), while those with traditional liquid-liquid extraction (LLE) are from 44.52% to 86.16% With RSDs being from 0.53% to 13.14% (n=3). Moreover, the reproducibility is greatly improved with SPE, with less solvent consumption and shorter processing time. The average efficiency of on-column derivatization for LOPs is 100.8%±0.68%, which is significantly higher than those of in-vial or in-syringe derivatization, thus resulting in still less consumption of derivatizing reagents.Lignin in the surface sediments sampled from the south of Yangtze River estuary, China, was determined with the established method. Recoveries of 72.66% to 85.99% with standard deviation less than 0.01mg/10g dry weight are obtained except for p-hydroxybenzaldehyde. The lignin content ∑8 (produced from 10g dry sediment) in the research area is between 0.231 and 0.587mg. S/V and C/V ratios (1.028 ± 0.433 and 0.192±0.066, respectively) indicate that the TOMs in this region are originated from a mixture of woody and nonwoody angiosperm plants; the high values or (Ad/Al)v suggest that the TOMs has been highly degraded. 展开更多
关键词 LIGNIN alkaline cupric oxide SPE on-column derivatization marine sediments
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Solubility of red palm oil in supercritical carbon dioxide: Measurement and modelling 被引量:1
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作者 Wan Jun Lee Chin Ping Tan +1 位作者 Rabiha Sulaiman Gun Hean Chong 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第5期964-969,共6页
The solubility of red palm oil (RPO) in supercritical carbon dioxide (scCO2) was determined using a dynamic method at 8.5-25 MPa and, 313.15-333.15 K and at a fixed scCO2 flow rate of 2.9 g. mn -1 using a full fac... The solubility of red palm oil (RPO) in supercritical carbon dioxide (scCO2) was determined using a dynamic method at 8.5-25 MPa and, 313.15-333.15 K and at a fixed scCO2 flow rate of 2.9 g. mn -1 using a full factorial design. The solubility was determined under low pressures and temperatures as a preliminary study for RPO par- ticle formation using scCO2. The solubility of RPO was 0.5-11.3 mg. (g CO2) -1 and was significantly affected by the pressure and temperature. RPO solubility increased with pressure and decreased with temperature. The Adachi-Lu model showed the best-fit for RPO solubility data with an average relative deviation of 14% with a high coefficient of determination, R2 of 0.9667, whereas the Peng-Robinson equation of state thermodynamic model recorded deviations of 17%-30%. 展开更多
关键词 SOLUBILITY Supercritical carbon dioxide Mathematical modelling THERMODYNAMICS Palm oil
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Determination of trace elements in high purity nickel by high resolution inductively coupled plasma mass spectrometry 被引量:11
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作者 聂西度 梁逸曾 +1 位作者 唐有根 谢华林 《Journal of Central South University》 SCIE EI CAS 2012年第9期2416-2420,共5页
The contents ofMg, Al, Si, Ti, Cr, Mn, Fe, Co, Cu, Ga, As, Se, Cd, Sb, Pb and Bi in high purity nickel were determined by high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS). The sample was diss... The contents ofMg, Al, Si, Ti, Cr, Mn, Fe, Co, Cu, Ga, As, Se, Cd, Sb, Pb and Bi in high purity nickel were determined by high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS). The sample was dissolved in HNO3 and HCI by microwave digestion. Most of the spectral interferences could be avoided by measuring in the high resolution mode. The matrix effects because of the presence of excess HC1 and nickel were evaluated. Correction for matrix effects was made using Sc, Rh and T1 as internal standards. The optimum conditions for the determination were tested and discussed. The detection limits range from 0.012 to 1.76 ~tg/g depending on the type of elements. The applicability of the proposed method is also validated by the analysis of high purity nickel reference material (NIST SRM 671). The relative standard deviation (RSD) is less than 3.3%. Results for determination of trace elements in high purity nickel were presented. 展开更多
关键词 high resolution inductively coupled plasma mass spectrometry high purity nickel trace element matrix effect internal standard
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Comparison between sequential and single extraction procedures for metal speciation in fresh and dried Sedum Plumbizincicola 被引量:4
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作者 宋祖威 仲兆平 +2 位作者 钟道旭 吴龙华 骆永明 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第2期487-494,共8页
Sequential and single extraction procedures were applied to both fresh and dried Sedum Plumbizincicola leaves and stems.The extractants, different from those of soil, sediment or sewage sludge metal fractions, were wa... Sequential and single extraction procedures were applied to both fresh and dried Sedum Plumbizincicola leaves and stems.The extractants, different from those of soil, sediment or sewage sludge metal fractions, were water, 80%(v/v) ethanol, 1 mol/L Na Cl,2% HAc and 0.6 mol/L HCl. Zn, Cd and Cu in the extracts and samples were measured by flame atomic adsorption spectrometry. In sequential extraction procedures, water soluble form and ethanol soluble form are the main fractions for Zn, while water soluble form and Na Cl soluble form for Cd, and comparatively uniform distribution for Cu with the residue form most and HCl soluble form second. Single extraction procedures are used to compare the extraction efficiencies of the five reagents to screen appropriate extractants and operating conditions for liquid extraction to deal with large amount of harvested metal-contained biomass, which will pose a threat to the environment if treated improperly. The sequences of extraction efficiencies are HCl>Na Cl≈HAc>Water≈Ethanol for Zn and HCl≈Na Cl≈HAc>Water>Ethanol for Cd. As for Cu, all the five extractants cannot effectively extract Cu, but HCl achieves a higher efficiency(>70% in fresh samples, and 45%-60% in dried samples). Besides, extraction efficiencies for most extractants in fresh samples are higher than those in dried samples, and extraction efficiencies of stems and leaves for the five extractants are close. The two extraction procedures can obtain high degree of accuracy with the relative standard deviation(RSD)lower than 10%, and metal recoveries are controlled between 80%-120% with most of 90%-110%. 展开更多
关键词 Sedum Plumbizincicola liquid extraction biomass disposal heavy metals
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Membrane preconcentration of iron in seawater samples and on-site determination in spectrophotometry 被引量:9
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作者 彭园珍 袁东星 +2 位作者 黄勇明 姜涛 刘宝敏 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2012年第2期315-320,共6页
A novel method for on-site determination of trace iron was developed using membrane preconcentration and spectrophotometric detection. Fe(II)-ferrozine complex was reacted with cetyltrimethylammonium bromide (CTAB... A novel method for on-site determination of trace iron was developed using membrane preconcentration and spectrophotometric detection. Fe(II)-ferrozine complex was reacted with cetyltrimethylammonium bromide (CTAB) to form a Fe(II)-ferrozine-CTAB paired compound, which was collected on a membrane by filtration under vacuum. The membrane was immersed in 2 mL of ethanol-nitric acid and the absorbance of the solution measured for quantitative analysis. Various factors affecting the iron collection and determination were investigated. With different sample preconcentration volumes, the range of determination was broadened to 0.5-120 ~tg/L. The detection limit of this method reached 0.19 ktg/L and the recoveries were between 97.2 and 109% when the concentration enrichment was about 45. The relative standard deviation (n = 7) was 1.9% for samples containing 10 ~g/L Fe. Twelve seawater samples were analyzed on-site using the proposed method, and two were also analyzed in inductively coupled plasma mass spectrometry. No significant difference was shown between the two methods by the Student's t-test. The method has also been used on-site for iron enrichment experiments with phytoplankton and concluded to be simple, accurate and inexpensive. 展开更多
关键词 IRON membrane filtration spectrophotometric detection
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Simultaneous Determination of Iron and Manganese in Water Using Artificial Neural Network Catalytic Spectrophotometric Method 被引量:4
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作者 JI Hongwei XU Yan +2 位作者 LI Shuang XIN Huizhen CAO Hengxia 《Journal of Ocean University of China》 SCIE CAS 2012年第3期323-330,共8页
A new analytical method using Back-Propagation (BP) artificial neural network and kinetic spectrophotometry for simultaneous determination of iron and magnesium in tap water, the Yellow River water and seawater is est... A new analytical method using Back-Propagation (BP) artificial neural network and kinetic spectrophotometry for simultaneous determination of iron and magnesium in tap water, the Yellow River water and seawater is established. By conditional experiments, the optimum analytical conditions and parameters are obtained. Levenberg-Marquart (L-M) algorithm is used for calculation in BP neural network. The topological structure of three-layer BP ANN network architecture is chosen as 15-16-2 (nodes). The initial value of gradient coefficient μ is fixed at 0.001 and the increase factor and reduction factor of μ take the default values of the system. The data are processed by computers with our own programs written in MATLAB 7.0. The relative standard deviation of the calculated results for iron and manganese is 2.30% and 2.67% respectively. The results of standard addition method show that for the tap water, the recoveries of iron and manganese are in the ranges of 98.0%-104.3% and 96.5%-104.5%, and the RSD is in the range of 0.23%-0.98%; for the Yellow River water (Lijin district of Shandong Province), the recoveries of iron and manganese are in the ranges of 96.0%-101.0% and 98.7%-104.2%, and the RSD is in the range of 0.13%-2.52%; for the seawater in Qingdao offshore, the recoveries of iron and manganese are in the ranges of 95.3%-104.8% and 95.3%-104.7%, and the RSD is in the range of 0.14%-2.66%. It is found that 21 common cations and anions do not interfere with the determination of iron and manganese under the optimum experimental conditions. This method exhibits good reproducibility and high accuracy in the determination of iron and manganese and can be used for the simultaneous determination of iron and manganese in tap water and natural water. By using the established ANN- catalytic spectrophotometric method, the iron and manganese concentrations of the surface seawater at 11 sites in Qingdao offshore are determined and the level distribution maps of iron and manganese are drawn. 展开更多
关键词 artificial neural network simultaneous determination kinetic spectrophotometric method iron MANGANESE
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Measurement of Trace Manganese(Ⅱ) by the Catalytic Kinetic Spectrophotometric Method 被引量:2
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作者 JI Hongwei SHA Yuanyuan XIN Huizhen QI Yanxia 《Journal of Ocean University of China》 SCIE CAS 2009年第2期127-132,共6页
A new kinetic spectrophotometric method is developed for the measurement of manganese(Ⅱ) in water. The method is based on the catalytic effect of manganese(Ⅱ) with the oxidation of weak acid brilliant blue dye(RAWL)... A new kinetic spectrophotometric method is developed for the measurement of manganese(Ⅱ) in water. The method is based on the catalytic effect of manganese(Ⅱ) with the oxidation of weak acid brilliant blue dye(RAWL) by KIO4 using the Nitrilo triacetic acid(NTA) as an activation reagent. The optimum conditions obtained are 40 mgL-1 RAWL,1×10-4molL-1 KIO4,2×10-4 molL-1 Nitrilo triacetic acid(NTA),pH = 5.8,the reaction time of 3.00 min and the temperature of 20.0 ℃. Under the optimum conditions,the proposed method allows the measurement of manganese(Ⅱ) in a range of 0-50.0 ng mL-1 and with a detection limit of down to 0.158 ng mL-1. The recovery efficiency in measuring the standard manganese(Ⅱ) solution is in a range of 98.5%-102%,and the RSD is in a range of 0.76%-1.25%. The new method has been successfully applied to the measurement of manganese(Ⅱ) in both fresh water and seawater samples with satisfying results. Moreover,few cations and anions interfere with the measurement of manganese(Ⅱ). Compared with other kinetic catalytic methods and instrumental methods,the proposed method shows fairly good selectivity and sensitivity,low cost,cheapness,low detection limit and rapidity. It can be applied on boats easily. 展开更多
关键词 MANGANESE kinetic-spectrophotometry catalytic effect weak acid brilliant blue dye (RAWL) seawater potassium periodate
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Correlation between welding and hardening parameters of friction stir welded joints of 2017 aluminum alloy 被引量:1
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作者 Hassen BOUZAIENE Mohamed-Ali REZGUI +1 位作者 Mahfoudh AYADI Ali ZGHAL 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第5期1064-1072,共9页
An experimental study was undertaken to express the hardening Swift law according to friction stir welding (FSW) aluminum alloy 2017. Tensile tests of welded joints were run in accordance with face centered composit... An experimental study was undertaken to express the hardening Swift law according to friction stir welding (FSW) aluminum alloy 2017. Tensile tests of welded joints were run in accordance with face centered composite design. Two types of identified models based on least square method and response surface method were used to assess the contribution of FSW independent factors on the hardening parameters. These models were introduced into finite-element code "Abaqus" to simulate tensile tests of welded joints. The relative average deviation criterion, between the experimental data and the numerical simulations of tension-elongation of tensile tests, shows good agreement between the experimental results and the predicted hardening models. These results can be used to perform multi-criteria optimization for carrying out specific welds or conducting numerical simulation of plastic deformation of forming process of FSW parts such as hydroforming, bending and forging. 展开更多
关键词 friction stir welding response surface methodology face centered central composite design HARDENING simulation relative average deviation criterion
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Fabrication of integrated resistors in printed circuit boards 被引量:1
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作者 王守国 陈清远 《Journal of Central South University》 SCIE EI CAS 2011年第3期739-743,共5页
In order to utilize integrated passive technology in printed circuit boards (PCBs), manufacturing processing for integrated resistors by lamination method was investigated. Integrated resistors fabricated from Ohmeg... In order to utilize integrated passive technology in printed circuit boards (PCBs), manufacturing processing for integrated resistors by lamination method was investigated. Integrated resistors fabricated from Ohmega technologies in the experiment were 1 408 pieces per panel with four different patterns A, B, C and D and four resistance values of 25, 50, 75 and 100 fL Six panel per batch and four batches were performed totally. The testing was done for 960 pieces of integrated resistors randomly selected with the same size. The value distribution ranges and the relative standard deviation (RSD) show that the scatter degree of the resistance decreases with the resistor size increasing and/or with the resistance increasing. Patterns D with resistance of 75 and 100% for four patterns have the resistance value variances less than 10%. Patterns C and D with resistance of 100 Ω have the manufacturing tolerance less than 10%. The process capabilities are from about 0.6 to 1.6 for the designed testing patterns, which shows that the integrated resistors fabricated have the potential to be used in multilayer PCBs in the future. 展开更多
关键词 integrated resistors lamination method printed circuit boards integrated passive technology
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Heavy metals accumulation effect in rabbit body fluids after smoking 被引量:2
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作者 钟狂飚 桂明 +3 位作者 朱立勇 李维 管茶香 郭方遒 《Journal of Central South University》 SCIE EI CAS 2011年第5期1408-1412,共5页
Concentration of heavy metals in blood and urine of rabbit after inhaling three different kinds of cigarette was studied through the animal passive smoking pattern. The samples were prepared by nitric acid solution di... Concentration of heavy metals in blood and urine of rabbit after inhaling three different kinds of cigarette was studied through the animal passive smoking pattern. The samples were prepared by nitric acid solution digestion and determination of seven kinds of heavy metals including Hg, Se, Sn, Pb, Cd, Ni and Cr was performed by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The ICP-AES method was established with good precision and accuracy, relative standard deviation (n=6) was between 2.9% and 5.9%, and the recovery was in the range of 95.0%-104.2%. Concentration of six heavy metals increases in some extent in blood and urine after period of smoking and the increasing of heavy metals in blood and urine all shows time dependence. Significantly higher heavy metal levels are observed in the blood and urine of the cigarette inhaling rabbits in the exposed group. The concentration of six kinds of heavy metals in the blood of the rabbit increases after 16 weeks exposing to cigarette smoking. Three times of rig, ten times of Se and trace amount ofPb, Cd, Ni and Cr are detected in the blood after 16 weeks of smoking. For urine samples, about three times of Hg, two times of Se, five times of Pb and trace amount of Cd are detected after 16 weeks of inhalation of cigarette. Comparatively, higher concentration of heavy metals are detected after inhaling of Nise cigarette. 展开更多
关键词 inductively coupled plasma-atomic emission spectrometry BLOOD URINE heavy metal element
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Optimization of Sample Pretreatment for Determination of Polycyclic Aromatic Hydrocarbons in Estuarine Sediments by Gas Chromatography 被引量:1
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作者 WANG Yan LI Xianguo +2 位作者 PENG Xuewei TANG Xuli DENG Xiaoyan 《Journal of Ocean University of China》 SCIE CAS 2012年第2期159-164,共6页
This study examined levels of polycyclic aromatic hydrocarbons (PAHs) in estuarine sediments in Licun (Qingdao, China) by gas chromatography under optimized conditions for sample pretreatment via ultrasonic extraction... This study examined levels of polycyclic aromatic hydrocarbons (PAHs) in estuarine sediments in Licun (Qingdao, China) by gas chromatography under optimized conditions for sample pretreatment via ultrasonic extraction, column chromatography, and thin layer chromatography. Methanol and dichloromethane (DCM)/methanol (2:1, v/v) were used in ultrasonic extraction, and DCM was used as eluate for column chromatography. The developing system consisted of n-hexane and DCM at a ratio of 9:1 (v/v), with DCM as the extraction solvent for PAHs-containing silica gel scraped off the plate. When the spiking level is 100 ng, total recoveries of spiked matrices for four target PAHs (phenanthrene, anthracene, pyrene and chrysene) were 83.7%, 76.4%, 85.8%, and 88.7%, respectively, with relative standard deviation (RSD) between 5.0% and 6.5% (n = 4). When the spiking level is 1000 ng, associated total recoveries were 78.6%, 72.7%, 82.7% and 85.3%, respectively, with RSD between 4.4% and 5.3% (n = 4). The opti-mized method was advantageous for determination of PAHs in complex matrix due to its effective sample purification. 展开更多
关键词 ultrasonic extraction thin layer chromatography estuarine sediment PAHS
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Determination of impurity elements in MnZn ferrites by inductively coupled plasma mass spectrometry 被引量:3
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作者 张萍 符靓 +1 位作者 马俊才 唐有根 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第1期37-42,共6页
An inductively coupled plasma mass spectrometry(ICP-MS) method was developed for the determination of Na, Mg, Al,K, Ca, Ti, Cr, Co, Ni, Cu, Ga, As, Mo, Ag, Cd and Pb in MnZn ferrites. The sample was digested by HNO3+H... An inductively coupled plasma mass spectrometry(ICP-MS) method was developed for the determination of Na, Mg, Al,K, Ca, Ti, Cr, Co, Ni, Cu, Ga, As, Mo, Ag, Cd and Pb in MnZn ferrites. The sample was digested by HNO3+HCl with microwave digestion followed by dilution with ultrapure water, then the above 16 impurity elements in the solution were analyzed directly by ICP-MS. The impurity elements were introduced by the helium gas or hydrogen gas into the octopole reaction system(ORS) to eliminate the polyatomic interferences caused by the high salty matrixes. The matrix effect was minimized through matrix matching,and Be, Y and Rh were used as internal standard elements. The working parameters of the instrument were optimized. The results show that the method has good precision and high accuracy. The detection limits for the investigated elements are in the range of0.9-37.5 ng/L, the relative standard deviation of each element is within 1.1%-4.8%, and the recovery of each element is 90%-108%. 展开更多
关键词 inductively coupled plasma mass spectrometry(ICP-MS) MnZn ferrites octopole reaction system(ORS) impurity elements
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On-line Separation and Preconcentration for Histamine Determination in Fish Meal Using Cation-Exchanger Resin 被引量:1
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作者 N. A. Fakhri M. S. Abdullah 《Journal of Food Science and Engineering》 2011年第4期282-288,共7页
FI system was used for the determination of histamine. A mini-column filled with amberlite resin (weak cation exchanger) was introduced to the flow system. A 200 laL of the sample was injected into the carrier strea... FI system was used for the determination of histamine. A mini-column filled with amberlite resin (weak cation exchanger) was introduced to the flow system. A 200 laL of the sample was injected into the carrier stream through the injection valve. The merged streams were passed through a quartz flow cell in a spectrophotometer connected to recorder. Under the optimum conditions, the calibration curve was linear in the range 0.02-1.5 μg mL^-1 of histamine using the peak height as an analytical signal, while the detection limit was 0.01 μg mL^-1. The precision and accuracy of the method were studied depending upon the values of the relative standard deviation and relative error percentage. The selectivity of the method was investigated by studying the effect of interference from other species accompanied with histamine in fish meal. Under the optimum conditions, the system was used for on line separation, preconcentration of histamine. The proposed method was applied for the determination of histamine in fish meal. The results were compared with the standard method and a good agreement between the results was obtained. 展开更多
关键词 SEPARATION PRECONCENTRATION HISTAMINE determination fish meal.
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Effect of sample treatment on determination of arsenic (Ⅲ) and arsenic (Ⅴ) in aqueous and tissue samples by hydride generation atomic absorption spectrometry 被引量:1
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作者 Jamileh Salar-Amoli Tahereh Ali-Esfahani Jalal Hassan 《Journal of Chemistry and Chemical Engineering》 2009年第6期49-53,共5页
The purpose of this procedure was to optimize and improve a method that used for the determination of arsenic (Ⅲ) and arsenic (Ⅴ) in biological and environmental samples. The method is based on hydride generatio... The purpose of this procedure was to optimize and improve a method that used for the determination of arsenic (Ⅲ) and arsenic (Ⅴ) in biological and environmental samples. The method is based on hydride generation and atomic absorption spectrometry. For both As (Ⅲ) and As (Ⅴ) the parameters such as NaBH4, HCI concentration, and pH were optimized. Absorption signal of As (Ⅴ) was approximately 17% of As (Ⅲ) signal. Therefore, for estimation of As (Ⅲ) and As (Ⅴ) concentrations in various samples the difference between the absorbance obtained for arsenic, without and with previous treatment of samples with potassium iodide (KI), can be applied. The calibration graphs were linear (r〉0.99), and the detection limits of the method based on three times the standard deviation of the blank were 0.14 and 0.64 μL^-1 for As (Ⅲ) and As (Ⅴ), respectively. The relative standard deviation (R.S.D.) of measurements was less than 10%. As a means of checking performance method, water samples were spiked with known concentrations of both As (Ⅲ) and As (Ⅴ), and recovery above 94% was obtained. The proposed method was applied successfully to determine inorganic As (Ⅲ) and As (Ⅴ) in various environmental and total As in biological samples. 展开更多
关键词 arsenic speciation hydride generation atomic absorption spectrometry
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HPLC Analysis of Egg Yolk Phosphatidylcholine by Evaporative Light Scattering Detector 被引量:1
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作者 周婧 胡仙妹 +2 位作者 王田心 梁浩 袁其朋 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2012年第4期665-672,共8页
Egg yolk phosphatidylcholine(EYPC) is being widely used in food and pharmaceutical industries nowadays owing to its surface activity,pharmaceutical usefulness,and so on.Common determination methods of phospholipids we... Egg yolk phosphatidylcholine(EYPC) is being widely used in food and pharmaceutical industries nowadays owing to its surface activity,pharmaceutical usefulness,and so on.Common determination methods of phospholipids were based on the American Oil Chemists' Society(AOCS) Official Method Ja7b-91,in which n-hexane/2-propanol/acetate buffer was used as the mobile phase.In order to achieve desired results,gradient elu-tion or buffer solution was used,which made the detection process more complicated.Moreover,water or buffer solution could affect the silica gel column both on its lifespan and the separation efficiency significantly.In this study,different mobile phase and detector were used to simplify EYPC analyzing process instead of using water within the mobile phase.The optimized HPLC operating conditions are as follows:pure methanol as a mobile phase,flow rate of 1.0 ml·min-1,silica gel column(250 mm×4.6 mm,5 μm,Inertsil GLTM),column temperature 30 ℃ and low temperature evaporative light scattering detector(40 ℃,0.35 MPa) as used.Under this optimal condition,the linear relative coefficient of the standard curve is 0.998 and the recovery was in the range of 96.83%-101.58% with a relative standard deviation of 1.79%(n=6). 展开更多
关键词 egg yolk phosphatidylcholine high performance liquid chromatography evaporative light scattering detector
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Assessment of Triazine Herbicides in Soil by Microwave-assisted Extraction Followed by Gas Chromatography Coupled to Mass Spectrometry Detection 被引量:1
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作者 Darlan Ferreira Silva Maria Diva Landgraf Maria Olimpia Oliveira Rezende 《Journal of Chemistry and Chemical Engineering》 2017年第1期1-8,共8页
An alternative and fast method for the analysis of a mixture of nine triazines herbicides in soil is presented. The method is based on MAE (microwave-assisted extraction) of herbicides using ethyl acetate as extract... An alternative and fast method for the analysis of a mixture of nine triazines herbicides in soil is presented. The method is based on MAE (microwave-assisted extraction) of herbicides using ethyl acetate as extractant. The economy in the use of solvents coupled with the decrease in extraction time and lower power consumption make MAE a technique that meets the principles of green chemistry. MAE operational parameters, extraction time, mass of the sample and extraction temperature, were optimized by RSM (response surface methodology). Determination of analytes was completed using gas chromatograph coupled to mass spectrometry detection. The selected triazines could be efficiently extracted by the solvent at 80 ℃ for 10 min, with 80% output of maximum power. When the optimized method was applied to analysis samples, the recoveries of analytes ranged from 81.8 to 106.0% and relative standard deviations were lower than 8.41%. The method is stable and reasonable, which can be used for the determination of ninetriazine herbicides residues in soil. 展开更多
关键词 Factorial design response surface methodology microwave-assisted extraction HERBICIDES triazines.
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Dispersion of SiC particles in mechanical stirring of A356-SiC_p liquid
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作者 张君 张鹏 +1 位作者 杜云慧 姚莎莎 《Journal of Central South University》 SCIE EI CAS 2012年第6期1503-1507,共5页
In order to clarify the dispersion of SiC particles in straight-blade mechanical stirring of A1-SiCp liquid, the dispersion of SiC particles in A356-3.5% SiCp (volume fraction) liquid in a cylindrical crucible was s... In order to clarify the dispersion of SiC particles in straight-blade mechanical stirring of A1-SiCp liquid, the dispersion of SiC particles in A356-3.5% SiCp (volume fraction) liquid in a cylindrical crucible was studied. The relationship between rotating speed of stirrer and radial relative deviation of SiCp content in A356 liquid between the center and the periphery of crucible was established in the conditions of 35° for the gradient angle a of blade and 10 mm/s for the speed of moving up and down of stirrer. The results show that the radial relative deviation of SiCp content increases gradually with increasing the rotating speed of stirrer. When the rotating speed of stirrer is 200 r/min, the vertical dispersion of SiC particles in A356 liquid is even, but the radial relative deviation of SiCp content is 0.24. Consequently, the northomogeneous dispersion of SiC particles in A356 liquid is mainly resulted from the nonhomogeneous radial dispersion of SiC particles. 展开更多
关键词 DISPERSION straight-blade mechanical stirring A356-SiCp liquid
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