振动膜型真空计的特性

现己发明一种用来对１０－３～２０乇范围的压强进行连续测量的振动膜型真空计。测量压强的方法有两种。一种方法的依据是振动膜的振幅依赖于气体压强。用这种方法得到了下列特性：（１）在０．２乇时的应答时间为０．０６秒３（２）灵敏度对温度的依赖性在０．２毛时为０．０８％／℃、。在１０乇时为－ ０．２％／℃（３）在室温时的可重复性小于 ０．７％。另一种方法的依据是膜的共振频率依赖于气体压强。由此法得到的显著特性是灵敏度对气体种类的依赖性很小。例如,对空气和氦气的灵敏度的差在１０乇时为４％。     

同时提取与测定食品中多种添加剂

本文介绍一种适用于食品中脱氢乙酸、安赛蜜、山梨酸、苯甲酸、糖精钠同时提取与测定的方法。此方法对于非高蛋白高脂肪液体样品。回收率为95％;对于高蛋白、高脂肪的样品,回收率为80％。方法检出限为3．0μg/g。     

微波消解ICP-AES测定海绵铁中杂质元素含量的研究

运用微波消解处理海绵铁试样,结合ICP—AES测定钙、镁、硅、铝、磷、钾、钠等7种杂质元素。加标回收率在92．4％-101．8％,精密度为0．55％-3．85％,方法准确,分析速度快,效率高,在日常快速分析检测中有重要意义。     

水质快速检测方法与国标法在水质检测中的应用比较分析

目的：分析研究水质快速检测方法与国标法在水质检测中的应用效果。方法：抽取20份水样,并将其中5份混合;分别利用水质快速检测方法以及国标法进行单份水样检测以及合成水样检测;分析比较两种检测手术的准确性以及精密度。结果：水质快速检测法在检测单份水质样品时,其对于氨氮检测得出的平均相对标准偏差为14．6％,其与国家标准检测方法的平均偏差为11．1％,对亚硝酸盐氮检测得出的平均相对标准偏差为15．2％;其与国家标准检测方法的平均偏差为14．8％;对总铁检测得出的平均相对标准偏差为23．4％;其与国家标准检测方法的平均偏差为22．5％;对合成水样的检查,国标法的检测偏差在10％以内,而快速检测法偏差则大于10％。结论：虽然快速检测法的精确度以及准确度均与国标法存在一定差异,但是该种检查方式具有检测快捷、操作方便的优点,因此其可以作为一种对水样进行初次筛选的检测手法来进行应用。     

头发中9种碱性染料的HPLC-DAD检测方法

文中建立了HPLC-DAD同时测定头发中碱性橙31等9种碱性染料的方法。方法以甲醇为提取溶剂,采用xB—c18柱,以乙腈-0．02mol／L乙酸铵（含0．05％甲酸）为流动相进行梯度洗脱,二极管阵列检测器检测。试验的平均回收率为93．9％～102．5％,相对标准偏差为1．2％～3．5％,最低检测浓度为0．15～0．60mg／kg。结果表明该方法前处理简单、快速,适用于测定头发中碱性橙3l等9种碱性染料组分的含量。     

粒子增强铝基复合材料的制取新工艺及其磨损性能

采用新的工艺方法制得三种不同的粒子增强复合材料,即在Al-1.8Si-0.4Mg-0.36Cu合金液中加入外加粒子,经搅拌喷氮气快速冷却获得颗粒为0.3～1.0mm的预制料,再经筛选、配料、预压块和热压(620℃压力为20MPa保压2～5分钟)制得含6％SiC、4％SiC_+2％石墨等三种铝基复合材料。这三种复合材料中外加粒子分布均匀,与基体结合良好,其磨损性能以加入6％SiC最佳,4％SiC+2％石墨次之,4％石墨最差。三种复合材料的磨损损伤的主要方式是粘着磨损。     

氢化物发生-原子荧光光谱法同时测定食盐中的砷和汞

建立一种氢化物发生-原子荧光光谱法同时测定食盐中砷和汞的方法.研究样品前处理对测定结果的影响,探索同时测定砷、汞的最佳实验条件.优化条件下,砷、汞质量浓度分别在0～10.0 μμg/L和0～2.0μg/L范围内,线性关系良好.方法检出限:As为0.0043 μg/L,Hg为0.003 2 μg/L;相对标准偏差:As为0.37％,Hg为0.61％;样品加标回收率:As为97.80％ ～ 102.40％,Hg为96.78％～ 100.80％.试验表明:该方法具有操作简便、快速、准确度高等优点,可用于食盐中砷汞的同时测定.     

高效液相色谱法定量分析化妆品中对羟基苯甲酸酯

建立了用高效液相色谱测定化妆品中对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯和对羟基苯甲酸丁酯4种防腐剂的方法。以甲醇与水作为流动相,DAD检测器的检测波长254nm,流速为1．0mL／min,柱温30℃。方法检出限分别为对羟基苯甲酸甲酯0．18μg、对羟基苯甲酸乙酯0．20μg、对羟基苯甲酸丙酯0．20μg、对羟基苯甲酸丁酯0．21μg。4种防腐剂在0～100mg／L呈现良好的线性关系。样品的加标回收率为101.3％～102.5％,相对标准偏差为0．13％～O．21％     

409L和410S热轧不锈钢在5种介质中的腐蚀行为

过去,用电化学和浸泡方法综合研究409L,410S热轧不锈钢的腐蚀性能不够。通过电化学和浸泡试验研究了409L和410S2种热轧不锈钢在80％H2SO4,10％HCl,20％NaOH,6％FeCl3及混合酸（3．2％HCl＋3．8％HNO3）中的耐蚀性能,并与奥氏体不锈钢304作对比。结果表明：3种钢的耐腐蚀能力为30...     

喹啉沥青的合成及其富氮衍生炭的微观结构研究

富氮炭材料作为一种性能优异的功能材料,在化学催化、吸附分离、电极材料、储氢、染料废水处理等领域拥有广阔的应用前景.而富氮沥青由于原料丰富、制备方法相对简单且易大规模生产,作为一种优秀的富氮前驱体近年来受到人们的青睐.本工作以含氮单体喹啉为原料,5％(质量分数)的AlCl3为催化剂,采用自升压法合成了四种喹啉沥青(QLP),利用傅立叶变换红外光谱、凝胶渗透色谱、热重分析仪对四种QLP的理化性质进行表征.通过元素分析、PLM、Raman和XRD研究了喹啉沥青衍生炭(CQLP)的氮含量及微观结构随炭化温度的变化情况.结果表明,四种QLP的收率都在90％左右,软化点在120℃左右,灰分小于2.5％,质均分子量为360～390,数均分子量为250～260.四种QLP的芳香指数(Iar)为0.55～0.69,邻位取代指数(Ios)为0.52～0.72,支链化指数(CH3/CH2)为0.11～0.23,750℃下的残炭率在29.0％ ～50.7％,其大小取决于合成条件.QLP的氮含量为8.22％,其氮含量随炭化温度升高呈先增加后略有下降的变化趋势,750℃下获得的CQLP具有最高的氮含量,为9.70％.三种CQLP的显微结构都以片状、纤维状组织为主,其含量分别占50％ ～60％和10％ ～30％,表现出良好的石墨化性.随炭化温度升高,CQLP的炭微晶尺寸增大,层间距减小,但规整性下降.     

液态羧酸催干剂中金属皂的ICP-AES法测定

本文提出了用盐酸溶样,ICP-AES法同时测定催干剂中的金属皂,并对不同的溶样方式和测定方法进行比较,讨论了ICP-AES法的干扰情况。测试结果表明,该法具有简单、快速、准确等优点。     

气相色谱法测定茶色素中的乙酸乙酯残留量

本文建立了一个气相色谱法测定茶色素中的乙酸乙酯残留量的方法。方法的回收率为100.1％～101.1％,相对标准偏差为2.0％,检测限为2ng(S/N≥3).测定结果表明:方法具有简单、可靠、快速、准确等特点。     

微波消解ICP-AES法测定钼矿石中多种元素

建立了电感耦合等离子体发射光谱法同时测定钼矿石中钼、铜、铅、钨、钛、硫6中元素含量的分析方法。采用微波消解溶解样品,在选定的仪器工作条件下直接测定。通过试验确定了各元素的分析谱线,对试液的酸度进行了探讨。6种元素的检出限为0.042~0.612μg/ml,加标回收率为97.01%~101.59%,测定结果的相对标准偏差0.89%~3.56%(n=6).该方法灵敏度高,适用于钼矿石中多种元素的同时测定。     

ICP-AES法测定封严涂层中BN含量

利用IC－AES法测定了封严涂层的BN，并对样品的溶解方法，仪器工作参数，光谱干扰等进行了研究。方法的相对标准偏差＜2％（n=10)，加标回收率在95％以上，方法简便，可靠，结果令人满意。     

基质固相分散萃取-气相色谱同时测定茶叶中有机氯及拟除虫菊酯类农药残留

建立了气相色谱-电子捕获检测器(GC-μECD)同时测定茶叶中14种有机氯和8种拟除虫菊酯类农药残留。采用基质固相分散(Matrix Solid Phase Disperse,MSPD)技术对茶叶样品进行前处理,用气相色谱-电子捕获检测器快速定性定量分析。MSPD集提取、过滤、净化于一步完成,避免了样品均化、转溶、乳化、浓缩造成待测农药组分的损失,大大提高了方法的准确性和精密度。添加回收实验结果表明:22种农药的平均回收率为83.5%~112.6%,相对标准偏差为2.5%~10.6%,方法检出限为0.002~0.02mg/kg。该方法灵敏度、准确度和精密度均符合农药残留测定的要求。     

Determination of trace lead in water samples by continuous flow microextraction combined with graphite furnace atomic absorption spectrometry

A new method of continuous flow microextraction (CFME) combined with graphite furnace atomic absorption spectrometry (GFAAS) was proposed for the determination of trace lead in water samples. A drop of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) dissolved in benzene is injected into a glass chamber by a microsyringe and held at the outlet tip of a PTFE connecting tube, the sample solution flows right through the tube and the glass chamber, the solvent drop interacts continuously with the sample solution, and the analyte was extracted into the drop and concentrated. After extracting for a period of time, the drop was retracted into the microsyringe and directly injected into graphite furnace for determination of Pb. Several factors affecting the extraction efficiency, such as solution pH, sample flow rate, drop volume and extraction time, were optimized. Under the optimized conditions, a concentration factor of 45 was achieved, and the detection limits for Pb were 12 pg mL(-1). The relative standard deviation for six replicate analyses of 10 ng mL(-1) Pb was 6.8%. The proposed method was applied to determine of trace Pb in water samples with satisfactory results.     

Solid phase extraction of lead on octadecyl bonded silica membrane disk modified with Cyanex302 and determination by flame atomic absorption spectrometry

A simple, reliable and rapid method for preconcentration and determination of lead using octadecyl bonded silica membrane disk impregnated with Cyanex302 and flame atomic absorption spectrometry is presented. The influence of aqueous phase pH, type of eluent, flow rates of sample solution and eluent, volume of eluent and amount of extractant has been investigated. The break through volume is greater than 4.0 dm(3) with an enrichment factor of more than 400 and a detection limit of 1.0microg dm(-3). The method developed for determination of lead is good as six replicate determinations using 100cm(3) solution containing lead in the range 1-4900microg provides a relative standard deviation (R.S.D.) of 0.4%. The selectivity of the proposed method was confirmed from the interference studies. The developed procedure was successfully applied for the determination of lead in spiked sea water, USGS standard soil sample, sludge and industrial effluents, medicinal formulation, plant, some food products and wine.     

Determination of decabromodiphenyl ether in backcoated textile preparation

A simple and reproducible chromatographic method for determination of decabromodiphenyl ether (DBDPE) is presented. The mobile phase consisted of aqueous acetonitrile solution. A simple quantitative extraction method using a soxhlet extraction is proposed to extract decabromodiphenyl ether from textile backcoated sample, and, a rapid chromatographic method using spectrophotometric detection, is described for the determination of decabromodiphenyl ether. The proposed method is applied for the determination of the decabromodiphenyl ether in a backcoated textile. Complete methods validation for both the extraction and analytical methods are discussed. Linear calibration curve in a range of 0.3-300.0mg/microL is achieved with a detection limit of 0.1microg. The method is successfully applied to the determination of decabromodiphenyl ether in several backcoated formulations.     

Speciation and determination of ultra trace amounts of chromium by solidified floating organic drop microextraction (SFODME) and graphite furnace atomic absorption spectrometry

Solidified floating organic drop microextraction (SFODME) method in combination with graphite furnace atomic absorption spectrometry (GFAAS) has been used for the determination of chromium species in water and urine samples. 1-undecanol containing 2-thenoyltrifluoroacetone (TTA) was used as a selective chelating agent for the extraction of Cr(III). The total Cr was determined after the reduction of Cr(VI) to Cr(III) with hydroxylamine. The concentration of Cr(VI) was determined from the difference between the concentration of total chromium and the Cr(III). Several variables such as the sample pH, concentration of TTA, salt concentration, extraction time and the sample volume were investigated in detail. Under the optimum conditions, the limit of detection of the proposed method was 0.006 μg l(-1) for Cr(III) and the relative standard deviation for six replicate determinations at 0.1 μg l(-1) Cr(III) was 5.1%. The proposed method was successfully applied for the determination of chromium species in tap water, well water, mineral water, and urine samples.     

火焰原子吸收分光光度法测定低合金钢中镍含量的不确定度评价

依据GB/T 223.54—1987利用火焰原子吸收分光光度法对低合金钢中镍进行了测定,对测定过程中不确定度的来源进行了分析,并对测定过程中的不确定度分量进行了合理评定,评定了测量结果的不确定度。找出了影响检测的主要因素,测量不确定度主要来源于试样称量、试样溶液定容和试样溶液质量浓度测定三方面,试样溶液质量浓度上机测定引入的不确定度主要来源于校准溶液配制、校准曲线拟合及重复性测定等,通过分析,明确了提高测量准确度的方法,给出了评定方法、步骤及结果。