蒸汽萃取-高效液相色谱紫外/荧光法同时测定果蔬中噻苯咪唑、邻苯基苯酚、联苯及抑霉唑残留

建立了一种快速同时测定果蔬中噻苯咪唑（TBZ）、邻苯基苯酚（OPP）、联苯（DP）及抑霉唑（IMZ）残留量的高效液相色谱紫外/荧光分析方法。柑橘类水果及蔬菜样品经组织捣碎机打碎研磨均匀后,利用咖啡萃取机产生的甲醇或乙醇蒸汽进行萃取,分别采用紫外/荧光检测器同时测定上述四种或三种防腐保鲜剂。结果表明：紫外检测TBZ、OP...     

HPLC-ICP-MS法测定水样中的甲基汞、乙基汞和无机汞

建立了高效液相色谱(HPLC)和电感耦合等离子体质谱(ICP-MS)联用测定环境水样中的甲基汞、乙基汞和无机汞的方法。实验使用的高效液相色谱流动相为含有0.06mol/L乙酸氨,20μg/LBi,0.1%(V/V)2-巯基乙醇的5%(V/V)甲醇-水溶液,色谱柱为C18反相柱(5μm,2.1mm×50mm),经前处理的水样在液相色谱中分离后,进入电感耦合等离子体质谱检测其甲基汞、乙基汞和无机汞的浓度。甲基汞、乙基汞和无机汞检出限分别为0.05μg/L、0.10μg/L和0.10μg/L。     

气相色谱-负化学电离质谱法测定茶叶中氟乐灵、三唑酮、丙溴磷的残留量

建立以固相萃取净化和气相色谱-负化学电离质谱(GC/NCI/MS)技术测定茶叶中氟乐灵、三唑酮、丙溴磷残留量的方法。样品经正己烷-丙酮(1+1)提取,共提物中的基体杂质经Cleanert TBT固相萃取柱去除,用负化学源质谱检测。氟乐灵、三唑酮、丙溴磷三种农药的方法回收率在74.3～98.1%之间,室内变异系数在6.2～12.5%之间(n=6),方法的检出限分别为1μg/kg、5μg/kg、10μg/kg。     

含油脂食品中邻苯二甲酸酯的前处理及其GC-MS测定方法

建立了15种邻苯二甲酸酯的提取-固相萃取净化-气相色谱/质谱检测分析方法。讨论了含油脂食品中邻苯二甲酸酯的提取、净化方法,优化了色谱分离条件。研究表明,该前处理方法具有较高的净化效率,且缩短了整个检验所需时间;15种邻苯二甲酸酯的方法线性范围为50～2000μg/L,相关系数均大于0.999,加标样品在200μg/L和2000μg/L两个浓度水平下,相对标准偏差在1.1%～11.2%范围,除邻苯二甲酸二甲酯较低外,样品加标回收率均在70%～120%之间。检测限在0.07～1.2μg/L范围(S/N=3)。     

气相色谱-质谱法检测牛奶中左旋咪唑残留的研究

目的:建立牛奶中左旋咪唑残留量检测的气相色谱-质谱方法。方法:牛奶样品经乙酸乙酯提取,盐酸反萃取后碱化,三氯甲烷提取液,可供气相色谱质谱联用仪分析。采用Agilent 6890N-5973i气-质谱联用仪,HP-5MS(30m×0.25 mm×0.25μm)毛细管柱,EI离子源,m/z 204、203、148、101选择离子监测,外标法定量。结果:左旋咪唑添加水平为5μg/L、10μg/L、50μg/L时,方法的回收率为76.5%~95.5%,批内批间相对标准偏差为1.4%~12.2%;在浓度为0.05~5μg/m L范围内左旋咪唑色谱峰面积与其质量浓度的线性方程为Y=16130X-164.37,r=0.9997。方法检测限为3μg/kg,定量限可达到10μg/kg。结论:所建立的GC-MS简便、快速,能够满足左旋咪唑残留检测的要求,可作为我国牛奶质量综合监控的有效方法之一,对我国动物性食品中左旋咪唑残留监控具有实际意义。     

一种自动石墨消解-ICP-MS法监测工业区土壤中微量砷、汞、硒、锑元素残留方法的建立

建立电感耦合等离子体质谱法监测工业区土壤样品中砷、汞、硒、锑4种微量元素残留的分析方法。利用全自动石墨消解仪消解工业园区土壤样品,盐酸-硝酸-氢氟酸体系作为消解酸体系,按照程序设置进行密闭消解,消解液用3%稀硝酸定容,电感耦合等离子体质谱仪定量检测砷、汞、硒、锑4种元素残留量。4种元素质量浓度在0.02～10μg/L范围内线性关系良好,相关系数(r2)0.995;4种元素加标回收率范围为84.5%～107.2%;检出限:砷0.001 8μg/L、汞0.003 4μg/L、硒0.007 4μg/L、锑0.001 0μg/L;精密度相对标准偏差RSD(n=6)在1.35%～3.51%之间,重复性相对标准偏差RSD(n=6)在2.47%～4.89%之间。结果表明,该方法具有前处理快速、检出限低、重复性好、检测结果准确可靠等优点,适用于工业园区土壤中微量元素残留的检测。     

气相-动态顶空进样-气相色谱/质谱法间接测定饮用水源水中苦味酸

建立气相-动态顶空进样-气相色谱/质谱法(D-HS-GC/MS)间接测定饮用水源水中苦味酸(即2,4,6-三硝基苯酚)的方法。基于苦味酸与次氯酸钠反应生成挥发性有机物———氯化苦(硝基三氯甲烷),气相-动态顶空进样技术可对水样液上气相空间的氯化苦进行吹脱捕集,通过气相色谱/质谱法测定氯化苦含量来间接测定苦味酸的浓度。结果表明:苦味酸浓度在1.00²0.0μg/L范围内呈良好的线性关系(r=0.9993),方法检出限为0.40μg/L;1.00,2.50,10.0μg/L标准点测得结果的相对标准偏差(RSD)分别为12.5%、9.2%和10.5%(n=7)。对实际水样进行分析,加标回收率为102%20.0μg/L范围内呈良好的线性关系(r=0.9993),方法检出限为0.40μg/L;1.00,2.50,10.0μg/L标准点测得结果的相对标准偏差(RSD)分别为12.5%、9.2%和10.5%(n=7)。对实际水样进行分析,加标回收率为102%¹31%,RSD为3.5%131%,RSD为3.5%¹6.6%(n=3)。     

HPLC法同时测定冬虫夏草中5种核苷类成分

用高效液相色谱法同时测定冬虫夏草中鸟嘌呤、胸腺嘧啶、腺嘌呤、腺苷、虫草素5种核苷类成分的含量。采用色谱柱为Aichrom Bond-AQ C18柱(250 mm×4.6 mm×5μm),以乙腈-水(7∶93)为流动相,流量为0.8 m L/min,检测波长254 nm,柱温30℃。鸟嘌呤、胸腺嘧啶、腺嘌呤、腺苷、虫草素的质量浓度分别在1.01~5.50μg/m L(r=0.9995)、0.05~1.01μg/m L(r=0.999 8)、0.20~1.98μg/m L(r=0.999 5)、1.01~5.07μg/m L(r=0.999 5)、0.10~1.03μg/m L(r=0.999 6)的范围内与峰面积线性关系良好,平均加样回收率分别为99.1%,97.8%,98.6%,100.4%,99.2%,RSD(n=5)分别为1.15%,2.34%,2.01%,1.75%,1.50%。该方法简便快速、准确度高、重现性好,可用于同时测定冬虫夏草中鸟嘌呤、胸腺嘧啶、腺嘌呤、腺苷、虫草素5种核苷类成分。     

微波消解-原子荧光光谱法测定中药中的砷和硒

建立了微波消解-原子荧光光谱测定中药中砷和硒含量的方法。该方法测定砷和硒的检出限分别为0.087μg/L和0.123μg/L,荧光强度与砷及硒的质量浓度在0~200μg/L及0~100μg/L范围内呈线性关系。用于中药中砷和硒的测定,相对标准偏差(n=6)均小于3.6%,砷的回收率在95.2%~102.8%之间,硒的回收率在94.5%~104.8%之间。     

盐析微萃取-气相色谱-质谱法测定实验室废水中7种苯系物

采用三氯甲烷作为萃取剂,氯化铵作为盐析剂,建立盐析微萃取-气相色谱-质谱法测定有机实验室废水中甲苯、乙苯、邻二甲苯、间二甲苯、对二甲苯、1,3,5-三甲苯、1,2,4-三甲苯的分析方法。当三氯甲烷用量为25μL,氯化铵用量为0.2 g,5 000 r/min下离心分离5 min时,1 m L水样中的苯系物能很好地被三氯甲烷萃取出来,富集倍数为40倍。色谱条件为:DB-5MS毛细管柱(30 m×0.25 mm×0.25μm),进样口温度220℃,载气为氦气,流量1 m L/min,分流比30∶1,进样量1μL,程序升温为:初始45℃保持3 min,3℃/min升温至70℃,再以30℃/min升至200℃保持2 min。质谱条件为:电子轰击离子源(EI),电子能量69.9e V,离子源温度240℃,四级杆温度150℃,电子倍增器电压1 741 V,采样深度1.5 mm,溶剂延迟3.5 min。在优化萃取和测定条件下,各组分的质量浓度在0.4~80μg/L内与峰面积线性关系良好,相关系数均大于0.992 5,各组分的检出限范围为0.01~0.5μg/L。对成都理工大学有机实验室中废水进行测定,能有效检出所含苯系物,同时做加标回收实验,回收率在92.92%~102.1%之间,相对标准偏差(n=5)在1.9%~4.5%之间,测定结果令人满意。     

p,V, T and derived thermodynamic data for toluene,trichloromethane, dichloromethane,acetonitrile, aniline,and n-dodecane

Experimentally determined p,V,T data are reported for toluene, trichloromethane, dichloromethane, acetonitrile, aniline, and n-dodecane at 278, 288, 298, 313, and 323 K, except for dichloromethane, for which the highest temperature was 298 K. At each temperature, measurements were done at pressures up to about 280 MPa or (for aniline and n-dodecane) at a lower pressure slightly below the freezing pressure at the temperature of measurement. Values of the isobaric expansivity isothermal compressibility and (for toluene, trichloromethane, dichloromethane, and acetonitrile) internal pressure, derived from the p,V,T data, are presented.     

微波消解-ICP-AES法测定茶叶中钾、钠、磷、硫、铁、锰、铜、锌、钙、镁方法研究

通过优化微波消解条件,并根据不同元素性质,调谐ICP-AES工作条件至最佳,实现了茶叶中K、Na、P、S以及Fe、Mn、Cu、Zn、Ca、Mg 10种元素的同时测定。10种元素测定结果 RSD%为0.67(Cu)～5.57(Na),回收率为84.0%(Na)～101.5%(Fe),检出限为0.001(Mn)～0.029(S)μg·g-1,表明该方法准确可靠,能够满足茶叶中K、Na、P、S、Fe、Mn、Cu、Zn、Ca、Mg分析要求。     

Optical properties of the metals Al, Co, Cu, Au, Fe, Pb, Ni, Pd, Pt, Ag, Ti, and W in the infrared and far infrared

Infrared optical constants collected from the literature are tabulated. The data for the noble metals and Al, Pb, and W can be reasonably fit using the Drude model. It is shown that -epsilon1(omega) = epsilon2(omega) approximately omega(2)(p)/(2omega(2)(tau)) at the damping frequency omega = omega(tau). Also -epsilon1(omega(tau)) approximately - (1/2) epsilon1(0), where the plasma frequency is omega(p).     

Dry Autoclaving for the Nanofabrication of Sulfides,Selenides, Borides,Phosphides, Nitrides,Carbides, and Oxides

This review compiles various nanostructures fabricated by a distinct “dry autoclaving” approach, where the chemical reactions are carried out without solvents; above the dissociation temperature of the chemical precursor(s) at elevated temperature in a closed reactor. The diversity to fabricate carbides (SiC, Mo₂C, WC), oxides (VOx‐C, ZnO, Eu₂O₃, Fe₃O₄, MoO₂), hexaborides (LaB₆, CeB₆, NdB₆, SmB₆, EuB₆, GdB₆), nitrides (TiN, NbN, TaN), phosphides (PtP₂, WP), sulfides (ZnS, FeS/C, SnS/C, WS₂, WS₂/C), and selenides (Zn_1‐xMn_xSe/C, Cd_1‐xMn_xSe/C), with various shapes and sizes is accounted with plausible applications. This unique single‐step, solvent‐free synthetic process opens up a new route in the growing nanomaterials science; owing to its considerable advantages on the existing approaches.     

抓管理重服务求可靠要效益--记广西计量测试研究所国家实验室认可工作

我所2001年9月份顺利地通过了中国实验室认可委紧张而严格的评审,得到了权威机构认可,成为西南地区较早通过国家实验室认可的省级计量校准机构.在建立质量体系、运行质量体系走过了艰辛之路,我们将全所职工的艰辛之路介绍给大家,希望能给将要申请认可的实验室得以参考.     

标准·质量·认证·会议(英文)

Standards IGRS:First Complete International Standards System in 3C Collaboration Field After ISO and IEC released three international standards of Intelligent Grouping and Resource Sharing (IGRS) including Core Protocol,File Communication Framework and Device Validation,four standards of IGRS,Application Framework,Basic Application,Service Types and Devices Types,got approved with high passing rate in the voting of Final Draft International Standard (FDIS) and will be officially issued soon around the world. It symbolizes that all     

Elastic, structural, bonding, and defect properties of zinc-blende BN, AlN, GaN, InN and their alloys

Simple tight-binding simulations, incorporating only the Herman–Skillman atomic term values, are shown to provide valuable information about the bonding, elastic and structural properties of zinc-blende group III-nitrides. Our calculated values of the elastic parameters (viz., bulk modulus, elastic stiffness constants, Kleinman's internal displacement parameter, Keating force constants, etc.) for BN, AlN, GaN, and InN are shown to exist well within the range of values derived from more sophisticated methods. Despite the crude approximations used, the tight-binding method has clearly provided the meaningful trends to the local distortions around isoelectronic impurities and has described reasonably well the bond length variations as a function of composition in ternary alloys.     

Powder X-Ray Reference Patterns of Sr2RGaCu2Oy (R = Pr,Nd, Sm,Eu, Gd,Dy, Ho,Er, Tm,and Y)

X-Ray Rietveld refinements were conducted on a series of eleven lanthanide phases, Sr₂RGaCu₂O_y (2112 phase, R = Pr, Nd, Sm, Eu, Gd, Dy, Ho, Y, Er, Tm, and Yb) that are structurally related to the high T_c superconductor Ba₂YCu₃O₇ (213). In the 2112 structure, instead of square planar Cu-O chains, tetrahedral GaO4 chains were found to run in a zig-zag fashion along the diagonal of the basal 213 ab-direction. Reference powder patterns for these compounds were prepared by using the Rietveld decomposition technique. The unit cell volume of these compounds follows the expected trend of the lanthanide contraction. The lattice parameters range from a = 22.9694(3) Å, b = 5.5587(2) Å, and c = 5.44743(7) Å for R = Pr, to a = 22.8059(2) Å, b = 5.46031(5) Å, and c = 5.37773(5) Å for R = Yb. An electon diffraction study of the Sm- and Er-analogs showed characteristic diffuse streaks along the b-axis, suggesting some disorder within the GaO₄ chains.