进口铜精矿中砷和汞的快速测定

试料经盐酸、硝酸溶解,添加硫脲和抗坏血酸预还原砷,以2%盐酸为载流,1%硼氢化钠和0.5%氢氧化钾溶液为还原剂,在氢化物发生器中,砷与硼氢化钠、盐酸反应生成砷化氢,汞则成为汞蒸气,用氩气导入石英炉原子化器中原子化,以空心阴极灯为激发光源,于原子荧光光谱仪上测量砷和汞的荧光强度。砷的标准偏差为0.0096%;汞的标准偏差为0.00015%,结果准确度较好。方法前处理快速,试剂消耗少,过程简单。     

氢化物发生–原子吸收光谱法测定铅粉中痕量砷、锑

建立氢化物发生–原子吸收光谱法联用测定铅粉中痕量砷、锑的方法。试样用稀硝酸溶解,用5%抗坏血酸溶液作为砷(Ⅴ)、锑(Ⅴ)的预还原剂,5%的硫脲溶液作为其它元素的掩蔽剂,选用1%硼氢化钠溶液作为还原剂,氢化物反应在10%盐酸介质中进行。在优化的试验条件下,砷、锑的质量浓度在0~20 ng/m L范围内与吸光度线性相关,相关系数r2分别为砷0.999 6,锑0.993 8,方法的检出限分别为砷0.40 ng/m L,锑0.75 ng/m L。砷、锑测定结果的相对标准偏差分别为4.96%,6.27%(n=6),铅粉样品加标回收率分别为砷87.6%,锑79.3%。该方法准确可靠,可用于测定铅粉中痕量砷、锑。     

流动注射——氢化物原子吸收法测定食品级碳酸钙中砷

用盐酸溶解碳酸钙试样,碘化钾-抗坏血酸预还原,硼氢化钠作还原剂,流动注射法发生砷化氢,并用氮气载入电热石英原子化器中进行原子化,在240·h的采样频率下,砷的特征浓度为0.2ng·ml~(-1),检出限(3σ)为0.6ng·ml~(-1),回收率为96.4%,相对标准偏差为3.3%.     

双通道原子荧光法同时测定水中砷和硒

采用双通道原子荧光法同时测定水中的砷和硒含量。以氢氧化钾–硼氢化钾溶液为还原剂,以硫脲–抗坏血酸–盐酸溶液为介质,在0~10μg/L范围内,砷、硒的质量浓度分别与荧光强度呈良好的线性,线性相关系数大于0.999,检出限分别为0.016,0.032μg/L。砷、硒测定结果的相对标准偏差为1.4%~1.5%(n=11),加标回收率在98.0%~102.0%之间。该方法操作简单、精确度高,适合于水中砷和硒含量的测定。     

氢化物发生-原子吸收法测定饮用水中的砷、硒

建立了测定饮用水中砷、硒的氢化物发生－原子吸收法，探讨了盐酸、硼氢化钠溶液的浓度以及样品还原处理对测定结果的影响，测定结果的相对标准偏差（n=7)小于3％，回收率为89．1％－110．7％，测定砷的线性范围为0－40ug/L(r=0.9990)，测定硒的线性范围为0－50ug/L(r=0.9990)，砷、硒的检出限分别为1．06，0．78ug/L。     

原子荧光光谱法同时测定食品中砷和硒

应用AFS-820双道原子荧光光谱仪,硝酸-硫酸消解样品,在硫酸-盐酸混合酸介质中,经盐酸预还原硒,以硼氢化钾还原形成硒烷和砷化氢,同时测定食品中砷和硒。砷和硒的检出限分别为0.42和0.58μg.L-1。通过对食品标样分析表明,测定结果与标准值相符,相对标准偏差(n=5)砷小于5.8%,硒小于7.2%。     

电热氢化物原子吸收光谱法测定水中痕量砷(Ⅲ)和砷(Ⅴ)

砷是环境污染物中重要监测元素。原子吸收法测定不同价态砷的文章不多。本文建立了以电热氢化物原子吸收光谱法测定水中砷(Ⅲ)与砷(Ⅴ)的含量。以硼氢化钠为还原剂,当溶液pH为5.8时,砷(Ⅲ)转化为气态砷化氢与母液分离,试样中砷(Ⅴ)不干扰测定。另取一份试样于2N盐酸介质中可用同样方法测定总砷量。再以差减法求砷(Ⅴ)含量。采用国产仪器及自制电热石英管原子化器灵敏度可达0.5ppb(1％吸收)。     

流动注射-氢化物发生原子吸收光谱法测定香烟接装纸中的痕量砷

将流动注射-氢化物发生和原子吸收光谱法有机的结合起来,探讨了流动注射-氢化物发生-原子吸收光谱法测定香烟接装纸中砷的最佳条件。样品经消解后,加入还原剂,使五价砷还原为三价,在盐酸介质中和硼氢化钾反应生成砷化氢,进入电热石英管原子化测定。检测结果相对标准偏差小于5%,加标回收率为96.7%~104%,方法检出限为0.18μg/L。     

氢化物发生-电感耦合等离子体原子发射光谱法测定血样中硒含量

样品经高氯酸-硝酸(1+4)混合溶液消化,以盐酸作为预还原剂,用氢化物发生-电感耦合等离子体原子发射光谱法测定全血中硒。在6mol.L-1盐酸溶液中加入溶于20g.L-1氢氧化钠溶液的5g.L-1硼氢化钠溶液使与溶液中硒离子反应生成氢化物。方法的检出限(3s/k)为1.8μg.L-1。应用此法测定2份血液样品中硒含量,方法的回收率在94.9%～107%之间,测定值的相对标准偏差(n=10)小于3%。     

微波消解–原子荧光法同时测定PM2.5中砷、汞含量

采用微波消解–原子荧光法测定PM2.5中砷、汞含量。实验结果表明,当还原剂硼氢化钾的质量分数为2%、溶液介质酸度为4%(体积分数)盐酸时,同时测定砷、汞可获得最佳的荧光值。砷、汞测定的检出限分别为0.027,0.006μg/L,空白滤膜的加标回收率分别为95.3%~101.7%,96.0%~106.0%,样品的加标回收率分别为95.0%~103.5%,93.3%~110.0%。该法检出限低,准确度高,适用于环境空气PM2.5中砷、汞含量的测定。     

Determination of arsenic in ores, concentrates and related materials by continuous hydride-generation atomic-absorption spectrometry after separation by xanthate extraction

A recent graphite-furnace atomic-absorption method for determining approximately 0.2 mug/g or more of arsenic in ores, concentrates, rocks, soils and sediments, after separation from matrix elements by cyclohexane extraction of arsenic(III) xanthate from approximately 8-10M hydrochloric acid, has been modified to include an alternative hydride-generation atomic-absorption finish. After the extract has been washed with 10M hydrochloric acid-2% thiourea solution to remove co-extracted copper and residual iron, arsenic(III) in the extract is oxidized to arsenic(V) with bromine solution in carbon tetrachloride and stripped into water. Following the removal of bromine by evaporation of the solution, arsenic is reduced to arsenic(III) with potassium iodide in approximately 4M hydrochloric acid and ultimately determined to hydride-generation atomic-absorption spectrometry at 193.7 nm, with sodium borohydride as reductant. Interference from gold, platinum and palladium, which are partly co-extracted as xanthates under the proposed conditions, is eliminated by complexing them with thiosemicarbazide before the iodide reduction step. The detection limits for ores and related materials is approximately 0.1 mug of arsenic per g. Results obtained by this method are compared with those obtained previously by the graphite-furnace method.     

水为载流-原子荧光光谱法同时测定土壤中痕量砷、汞

改变原子荧光光谱法以稀酸为载流的进样方式,以水为载流在新型双道原子荧光光谱仪上同时测定了土壤中的痕量砷(As)、汞(Hg)。方法采用王水水浴加热溶解样品,用50 g/L硫脲-抗坏血酸混合溶液预先将砷还原为+3价,保持10%(体积分数)以上盐酸浓度,不转移直接定容静置后测定。优化了仪器工作条件,详细考察了以水为载流测定的可行性,选择了同时测定As、Hg所需的硼氢化钾浓度和盐酸浓度。方法节省了酸试剂用量,操作快速,单个样品测定仅需20s左右。方法检出限As为0.005 mg/kg,Hg为0.0008 mg/kg,相对标准偏差(RSD%,n=7)在1.0%～7.4%,经土壤国家标准物质和实际样品验证,适合土壤中痕量As、Hg的同时快速测定。     

水载流-原子荧光光谱法同时测定土壤中痕量砷、汞

改变原子荧光光谱法以稀酸为载流的进样方式,以水为载流在新型双道原子荧光光谱仪上同时测定了土壤中的痕量砷(As)、汞(Hg)。采用王水水浴加热溶解样品,用50 g/L硫脲-抗坏血酸混合溶液预先将砷还原为As(Ⅲ),保持10%(体积分数)以上盐酸浓度,不转移直接定容静置后测定。优化了仪器工作条件,详细考察了以水为载流测定的可行性,选择了同时测定As、Hg所需的硼氢化钾浓度和盐酸浓度。节省了酸试剂用量,操作快速,单个样品测定仅需20 s左右。方法检出限As为0.005 mg/kg,Hg为0.0008 mg/kg,相对标准偏差(RSD,n=7)在1.0%~7.4%,经土壤国家标准物质和实际样品验证,适合土壤中痕量As、Hg的同时快速测定。     

氢化物发生–原子荧光光谱法同时测定锌锭中砷和锑

建立用氢化物发生–原子荧光光度计同时测定锌锭样品中砷和锑含量的方法。采用硝酸一次溶样,加入酒石酸防止锑水解。加入硫脲–抗坏血酸混合溶液作为还原剂和掩蔽剂,消除干扰元素的影响,对实验条件进行了优化。砷和锑的负高压分别为220,200 V,灯电流分别为80,60 mA,还原剂为1%硼氢化钾溶液(含0.5%KOH),载流为10%盐酸溶液,还原时间为30 min。测定砷的线性范围为0~80 ng/mL,相关系数r=0.999 8,检出限为0.35μg/L,测定结果的相对标准偏差为3.18%(n=11);测定锑的线性范围为0~80 ng/mL,相关系数r=0.999 6,检出限为0.42μg/L,测定结果的相对标准偏差为4.32%(n=11),砷和锑的加标回收率在97.46%~100.30%之间。用该方法对标准样品进行测定,测定结果与标准值相符。该方法基体干扰少,灵敏度高,适合于锌锭中砷和锑的日常测定。     

微波消解-氢化物发生原子荧光法同时测定土壤中的砷汞

建立了微波消解-氢化物发生原子荧光法同时测定土壤中As、Hg的分析方法。用体积分数35%的王水作为消解溶剂,在设定的微波消解条件下,可以将土壤中的As、Hg提取完全,有效解决了消解液中剩余酸过多的问题。方法用体积分数5%的HCl作为反应介质,20 g/L NaBH4作为还原剂。通过测定国家标准参考物质和加标回收实验,对方法进行了验证。已用于土壤中As、Hg的测定。     

高效液相色谱–原子荧光光谱法测定水产品中4种砷形态

建立高效液相色谱–原子荧光光谱法对水产品中4种砷形态[亚砷酸盐As(Ⅲ)、砷酸盐As(Ⅴ)、一甲基砷酸、二甲基砷酸]进行测定。优化后的实验条件:负高压为270 V,灯电流为80 m A,原子化高度为10 mm,硼氢化钾浓度为20 g/L(含5 g/L KOH),载流为体积分数5%的盐酸。方法的线性范围为0~100μg/L,线性相关系数大于0.999。各种砷形态的检出限为0.20~0.45μg/L;测量结果的相对标准偏差为1.98%~4.81%(n=6);加标回收率为88.4%~101.7%。该方法灵敏度高,快速、准确,检测成本低,可用于水产品中砷形态的检测。     

顺序注射氢化物发生-原子荧光光谱法同时测定中草药中As和Bi

建立了一种顺序注射氢化物发生-原子荧光光谱法同时测定中草药中的As和Bi含量的方法,考察了光电倍增管负高压、As和Bi灯电流、原子化器高度、载气流量、屏蔽气流量等因素对测定结果的影响。结果表明,载流HCl的浓度为0.3 mol/L,KBH4质量浓度为10 g/L时,同时测定As和Bi的效果最佳;在最佳实验条件下,As和Bi的检出限分别为0.058μg/L和0.006μg/L,加标回收率为94.6%~103.2%,相对标准偏差小于3.0%,中草药试样中共存的离子对As和Bi的测定没有干扰。该法操作方便、快速,用于中草药中As和Bi的同时测定,具有很好的可行性和实用性。     

Determination of antimony in ores and related materials by continuous hydride-generation atomic-absorption spectrometry after separation by xanthate extraction

A continuous hydride-generation atomic-absorption spectrometric method for determining approximately 0.02 mug/g or more of antimony in ores, concentrates, rocks, soils and sediments is described. The method involves the reduction of antimony(V) to antimony(III) by heating with hypophosphorous acid in a 4.5M hydrochloric acid-tartaric acid medium and its separation by filtration, if necessary, from any elemental arsenic, selenium and tellurium produced during the reduction step. Antimony is subsequently separated from iron, lead, zinc, tin and various other elements by a single cyclohexane extraction of its xanthate complex from approximately 4.5M hydrochloric acid/0.2M sulphuric acid in the presence of ascorbic acid as a reluctant for iron(III). After the extract is washed, if necessary, with 10% hydrochloric acid-2% thiourea solution to remove co-extracted copper, followed by 4.5M hydrochloric acid to remove residual iron and other elements, antimony(III) in the extract is oxidized to antimony(V) with bromine solution in carbon tetrachloride and stripped into dilute sulphuric acid containing tartaric acid. Following the removal of bromine by evaporation of the solution, antimony(V) is reduced to antimony(III) with potassium iodide in approximately 3M hydrochloric acid and finally determined by hydride-generation atomic-absorption spectrometry at 217.8 nm with sodium borohydride as reluctant. Interference from platinum and palladium, which are partly co-extracted as xanthates under the proposed conditions, is eliminated by complexing them with thiosemicarbazide during the iodide reduction step. Interference from gold is avoided by using a 3M hydrochloric acid medium for the hydride-generation step. Under these conditions gold forms a stable iodide complex.     

原子荧光光谱法测定粗锌中的砷

建立了测定粗锌中砷含量的原子荧光光谱法。粗锌样品经硝酸溶液(1+1)低温溶解完全以后,在盐酸介质中,用抗坏血酸预还原,以硫脲掩蔽铜、铁、银等杂质元素,砷被硼氢化钾还原为氢化物,用氩气导入原子化器测量。砷测定结果的相对标准偏差为1.5%~3.0%(n=11),加标回收率为98.4%~103.6%。与国家标准测定方法分光光度法测定结果对比,相对偏差为0.1%~2.4%。该法准确、可靠,适用于砷含量在0.005 0%~0.50%之间的粗锌中砷的测定。