氢化物发生-原子荧光光谱法测定地球化学样品中的锗

样品经硝酸-氢氟酸-硫酸混合酸消解,磷酸提取。通过对溶液的测定介质和介质浓度、KBH4浓度、灯电流等条件的优化及其对共存元素测定影响及其消除,建立了用原子荧光光谱法测定地球化学样品中微量锗的方法,方法检出限为33ng/g,测定范围为0.10~60μg/g,经国家一级标准物质验证,测定结果与标准值吻合;方法精密度好,准确度高。     

高压消解-电感耦合等离子体质谱(ICP-MS)法测定地质样品中的铌和钽

建立了运用硝酸-硫酸-氢氟酸体系高压消解样品,电感耦合等离子体质谱(ICP-MS)法测定地质样品中铌和钽含量的方法。研究了样品消解体系、样品消解时间、溶液的介质、内标元素等对测定的影响。Nb的方法检出限为0.027μg/g,Ta的方法检出限为0.015μg/g。Nb测定的相对标准偏差(RSD)为3.3%;Ta测定的相对标准偏差(RSD)为2.5%。经标准物质验证,分析结果令人满意,可适用于大批量地质样品中铌和钽的测定。     

电感耦合等离子体发射光谱(ICP-OES)法测定矿石中锑

通过探究样品溶解及测定方法存在的问题,确立了样品经硝酸-氢氟酸-高氯酸溶解,硫酸助溶,在盐酸介质中电感耦合等离子体发射光谱(ICP-OES)法直接测定矿石中锑的方法,其方法检出限为1.32μg/g,测定下限为5.28μg/g,相对标准偏差(RSD)小于5%,经标准物质和实际样品验证表明,方法简便、易行,结果准确,是现有矿石中锑测定方法的有效补充。     

火焰原子吸收光谱法测定硒碲混合物中的碲

建立了酒石酸-硝酸-盐酸混酸溶解样品,在王水-酒石酸介质中,采用空气-乙炔火焰在原子吸收光谱仪上测定硒碲混合物中碲的方法。研究了样品处理方法、乙炔流量、燃烧高度、灯电流、溶液介质等有关工作条件。实验表明碲浓度在1～20μg/mL范围内与吸光度呈良好的线性关系,回归方程为A=0.0229C+0.0009,相关系数0.9998,检出限0.08μg/mL。适合于硒碲混合物中碲的测定,相对标准偏差为0.9%～1.3%,回收率为98%～102%。     

电感耦合等离子体质谱法测定地球化学样品中砷的干扰校正方法

提出通过37Cl16O/52Cr校正40Ar35Cl对75As干扰的数学校正公式,考察了影响测定准确度的因素,包括HCl浓度、铬和钙的含量等,发现0~0.48 mol/L HCl、0~200μg/L铬和0~60 mg/L钙不影响砷的准确测定;本方法可以明显改善测定HCl介质中砷的准确度和精密度,降低检出限。在此基础上,建立了样品经逆王水水浴分解,电感耦合等离子体质谱直接测定勘查地球化学样品中砷的方法,方法检出限(3s)为0.12μg/g。经国家一级地球化学标准物质验证,测定值与标准值吻合。     

氢化物发生-原子荧光光谱法测定金属镁中痕量铅

样品以盐酸、过氧化氢进行溶解,以铁氰化钾作氧化剂,用氢化物发生-原子荧光光谱法测定金属镁中痕量铅。研究了氢化物发生的介质和酸度、硼氢化钾溶液的浓度、氢氧化钠的浓度、铁氰化钾的浓度对测定结果的影响,确定了最佳的测定条件。同时对仪器的操作参数进行了最佳选择。在最佳条件下,铅浓度在0~20μg/L范围内与荧光强度呈良好的线性关系,相关系数大于0.9995,方法的检出限为0.37μg/L。样品中铅的加标回收率在91%~102.7%之间,相对标准偏差为4.2%。     

KMnO_4-甲醛流动注射化学发光法测定木犀草素

在酸性介质中,木犀草素在KMnO4-HCHO体系中产生化学发光,据此建立了一种简便、快速测定木犀草素的化学发光新方法。化学发光强度与木犀草素的浓度在5.0×10-8~1.5×10-5g/mL范围内呈现出良好的线性关系。其检测限(3σ)为3.0×10-8g/mL,对8.0×10-7g/mL的木犀草素溶液进行11次平行测定,相对标准偏差为2.8%。方法可应用于实际样品和合成样品中木犀草素的测定。并探讨了反应的机理。     

火焰原子吸收光谱法测定地质样品中的砷

微量砷的测定方法主要是原子荧光光谱法;含砷量较高的样品测定,一般采用容量法和分光光度法,但这两种方法相对来说流程长,过程繁琐。实验对样品中中等含量砷的测定进行了研究,样品经酸溶后,在硝酸(1%)介质中,用火焰原子吸收光谱法在波长193.7nm处测其吸光度,结果表明吸光度与其质量浓度在0~100μg/mL呈线性关系。方法的测定相对标准偏差(RSD)为0.8%,检出限为10.5μg/g,实验操作简便,适合样品中较高含量砷的分析测定。     

氢化物发生–原子荧光光度法测定食品和食品添加剂中的砷、汞和铅

建立氢化物发生–原子荧光光度法测定食品和食品添加剂中砷、汞和铅元素的方法。对茶叶、方便面、精料与二氧化硅样品的前处理方法进行了研究,讨论了酸介质与酸度、还原剂浓度、铁氰化钾与草酸浓度等因素对样品测定的影响。当还原剂质量浓度为20 g/L、载流酸度为5%、铁氰化钾和草酸质量浓度分别为4 g/L和2 g/L时,砷、汞和铅的方法检出限分别为0.024,0.008,0.066μg/L,方法的回收率为85%~105%,测量结果的相对标准偏差分别为0.7%,0.7%,1.8%。该方法简便、快速、结果准确可靠,能满足食品和食品添加剂中砷、汞、铅的测定。     

氢化物发生-原子荧光光谱法测定低合金钢中微量砷

采用氢化物发生-原子荧光光谱法测定低合金钢中砷的含量。样品经盐酸-硝酸混合酸消解,以盐酸(5+95)溶液为反应介质,15g·L~(-1)硼氢化钾-2g·L~(-1)氢氧化钾的混合溶液为还原剂,采用柠檬酸作为掩蔽剂。砷的质量浓度在60.0μg·L~(-1)以内与荧光强度呈线性关系,方法的检出限(3s/k)为0.023μg·L~(-1)。应用此法对标准钢样进行了分析,测定结果与认定值相符合,可满足钢铁中微量砷(质量分数0.001%～0.04%)的测定要求。     

蒸馏分离–电感耦合等离子体质谱法测定铜铅锌矿石中微量锗

建立蒸馏分离-电感耦合等离子体质谱法测定铜铅锌矿石中微量锗的方法。采用硝酸-磷酸混合酸消解铜铅锌矿石样品,在盐酸介质中蒸馏分离微量锗,在氦气碰撞池模式下,以103Rh为在线内标进行质谱法测定。锗的质量浓度在0~50 μg/L 范围内线性良好,相关系数为0.9995,方法检出限为0.019 μg/g。用所建方法对3个铜铅锌矿石成分国家一级标准物质进行测定,测定结果的相对标准偏差为4.58%~5.55%(n=7),样品加标回收率为93.0%~102.0%。该方法操作简便,灵敏度高,适用铜铅锌矿石中微量锗含量的测定。     

火焰原子吸收光谱法测定粗锌中的铜

建立火焰原子吸收光谱法测定粗锌中的铜含量。采用硝酸–酒石酸溶解样品,并以其为测定溶液介质,检测波长为324.7 nm,以水为参比,采用空气–乙炔火焰以原子吸收光谱仪进行测定。在优化的实验条件下,铜的质量浓度在0.10~2.50μg/m L范围内与吸光度有良好线性关系,相关系数为0.999 7,方法检出限为0.01μg/m L。测定结果的相对标准偏差为1.0%~3.0%(n=11),样品加标回收率为97%~102%。该方法具有灵敏度高,干扰少,重现性好等优点,适用于铜含量在0.001%~0.50%之间的粗锌中铜的测定。     

HG-AFS 法测定多金属矿中的痕量锡

研究了酒石酸介质中氢化物发生原子荧光光谱法 ( HG- AFS)测定多金属矿中痕量锡的方法 ,考察了不同酸介质和浓度对氢化物发生效率的影响 ,试验了共存元素的干扰情况。方法的检出限为 1 .4× 1 0 - 10 g/ m L,精密度 ( n=5)为3.71 %～ 5.38%。     

Flow fluorimetry of trace amounts of uranium(VI) after preconcentration on a tri-n-octylphosphine oxide/polyethylene column and elution with hydrogenphosphate solution

The fluorescence of uranyl ion is enhanced in phosphoric acid medium and in hydrogen-phosphate medium. The pH dependence of the fluorescence intensity showed maxima at pH 1–2 and pH 7–8. The concentration of phosphoric acid which gave maximum intensity was around 1 M, but in the hydrogenphosphate media an increase in the concentration lowered the intensity. The procedure was used in combination with preconcentration on a tri-n-octylphosphine oxide/polyethylene column. This simple system provided a limit of detection of 0.04 μg for uranium and the calibration graph was linear for the range 0.08–0.8 μg of uranium when 4–15 ml of sample solution was passed through the column. The flow fluorimetric method was applied to the determination of uranium in a spinel.     

花菁-脱氧核糖核酸的共振光散射光谱及其分析应用

研究了一种苯并噻唑阳离子花菁与脱氧核糖核酸(DNA)作用的共振光散射光谱,在pH 6.0的六次甲基四胺-HCl缓冲介质中,痕量DNA的加入使花菁在590nm的共振光散射强度显著增强。在最佳实验条件下,增强的共振光散射强度与DNA浓度具有良好的线性关系,据此建立了一种测定DNA的共振光散射光谱法。方法的线性范围为:小牛胸腺DNA(CT DNA),0～20μg/mL,鱼精子DNA(FS DNA),0～15μg/mL;检出限分别为0.005μg/mL和0.008μg/mL。该方法已用于合成样品中DNA的测定。     

薄层扫描快速检测发酵液中琥珀酸

基于CuSO4与发酵液中琥珀酸的显色反应,在硅胶板上不经层析展开使用薄层扫描定量分析琥珀酸含量.在0～12 g/L范围内,测定波长680 nm,参比波长500 nm条件下,琥珀酸浓度与显色斑吸光度呈良好线性关系.方法检出限(3 S/k)为0.028 mg/L,回收率94.80％～96.12％,相对标准偏差≤3.5％(n...     

丹宁纤维素富集-氢化物发生ICP-AES同时测定水中痕量锗

研究了丹宁纤维素富集10~(-11)g/ml级锗的条件,并考察了地下水中36种共存离子对磷酸介质中氢化物发生ICP-AES测定锗的干扰和消除,应用于测定地下水中的超痕量锗,结果满意,检出限为15ng/L。     

Electrochemical hydride generation for the determination of hydride forming elements by atomic fluorescence spectrometry

The determinations of As, Bi, Ge, Sb and Se were performed by atomic fluorescence spectrometry following their electrochemical hydride generation. An electrochemical hydride generator based on a screw-thread seal arrangement, working in a continuous flow mode was used. The effects of cathode material, shape and area of material, catholyte, sample flow rate, applied current, catholyte solution concentration and interference of transition metals on signal intensity were studied. Five kinds of materials including lead, graphite, copper, tungsten and platinum with different shapes were tested as cathode materials. The signal obtained from a 3-dimensional electrode was higher than that from a 2-dimensional electrode under the same conditions. The signal intensity of Ge in HNO₃ medium within a narrow concentration range of 0.05–0.10 mol L^− 1 was stronger than that in other acidic medium, such as HCl and H₂SO₄. However, the signal intensity of Ge was rapidly decreased with HNO₃, HCl and H₂SO₄ concentration increasing, and then reached approximately zero. In general, limits of detection and a precision were improved using a graphite cathode in H₃PO₄ medium. The analysis of the reference materials showed good agreement with the certified values for As, Bi, Ge, Sb and Se. The method was successfully applied in the determination of As, Bi, Ge, Sb and Se in traditional Chinese medicine samples.     

Trace Determination of Germanium by Continuous Flow Hydride Generation Laser-Induced Fluorescence Spectrometry

A continuous flow hydride generation laser-induced fluorescence (HG-LIF) spectrometry technique has been investigated for performing trace determination of germanium (Ge). Hydride generation of Ge is performed using reagent concentrations of 2?M H₃PO₄ and 0.5% NaBH₄ and fluorescence detection is performed using tunable dye laser radiation at 253.323?nm for Ge excitation with fluorescence measured at 303.907?nm. The HG-LIF approach provides a linear response for Ge in the concentration range from 1.0 to 50?ng mL^?1 and a limit of detection of 0.1?ng mL^?1. Replicate measurements at 10?ng mL^?1 have a relative standard deviation of 0.1% (n?=?8). Measurements of Ge in different sample matrices have demonstrated the effectiveness of thiourea and ascorbic acid as masking agents that compensate for samples containing interfering ions. The determinations of the Ge content in reference water samples, fly ash samples, and supplement capsules demonstrate that the HG-LIF approach has feasibility for measuring Ge in different sample matrices at environmentally relevant concentrations.     

Slurry sampling flow injection chemical vapor generation inductively coupled plasma mass spectrometry for the determination of trace Ge,As, Cd,Sb, Hg and Bi in cosmetic lotions

A slurry sampling inductively coupled plasma mass spectrometry (ICP-MS) method has been developed for the determination of Ge, As, Cd, Sb, Hg and Bi in cosmetic lotions using flow injection (FI) vapor generation (VG) as the sample introduction system. A slurry containing 2% m/v lotion, 2% m/v thiourea, 0.05% m/v l-cysteine, 0.5 μg mL⁻¹ Co(II), 0.1% m/v Triton X-100 and 1.2% v/v HCl was injected into a VG-ICP-MS system for the determination of Ge, As, Cd, Sb, Hg and Bi without dissolution and mineralization. Because the sensitivities of the analytes in the slurry and that of aqueous solution were quite different, an isotope dilution method and a standard addition method were used for the determination. This method has been validated by the determination of Ge, As, Cd, Sb, Hg and Bi in GBW09305 Cosmetic (Cream) reference material. The method was also applied for the determination of Ge, As, Cd, Sb, Hg and Bi in three cosmetic lotion samples obtained locally. The analysis results of the reference material agreed with the certified value and/or ETV-ICP-MS results. The detection limit estimated from the standard addition curve was 0.025, 0.1, 0.2, 0.1, 0.15, and 0.03 ng  g⁻¹ for Ge, As, Cd, Sb, Hg and Bi, respectively, in original cosmetic lotion sample.