电感耦合等离子体原子发射光谱(ICP-AES)法测定电镀废弃物中的七种元素

采用HCl-HNO3-HF-HClO4体系溶解试料,电感耦合等离子体原子发射光谱法测定电镀废弃物中的钙、铝、镉、钴、铁、锰、镁七种元素含量。通过加标回收实验,这几种元素的加标回收率为96.1%~102%,相对标准偏差均小于3%(n=7),此方法操作速度快、检测效率高,是一种理想的分析方法。     

钙、镁、铁、铝离子对土壤中总氟化物检测干扰的消除

建立钙、镁、铁、铝离子对离子选择电极法检测土壤总氟化物干扰的消除方法。通过对含不同浓度水平钙、镁、铁、铝离子的土壤样品中总氟化物进行测试,明确了在总离子强度调节缓冲溶液共存下钙、镁、铁、铝离子对土壤提取液中总氟化物检测结果存在负干扰。通过测试10种土壤样品总氟化物提取液中干扰最强的背景铝含量,对其中土壤提取液中铝离子质量浓度大于10.0 mg/L的3种土壤样品进行加标回收试验,结果表明了土壤总氟化物含量为327～926 mg/kg范围内,当样品提取液中的铝离子含量为50～100 mg/L时,通过减少提取液取样体积为5.00 mL并增加柠檬酸三钠总离子强度缓冲溶液体积至15.0 mL的方法可将加标回收率由56.4%～78.3%优化至94.7%～104.0%;当加入Ca~(2+),Mg~(2+),Fe~(3+)质量浓度为200～300 mg/L,加标回收率由63.1%～77.6%优化为92.4%～105.0%。用优化后的方法测定土壤总氟化物含量为246～2 240 mg/kg的5种标准样品,测试结果与标准值一致。该方法能有效地消除土壤样品总氟化物测定中含钙、镁、铁离子质量浓度为200～300 mg/L,铝离子质量浓度为50～100 mg/L而产生的干扰,具有良好的适用性。     

EDTA络合滴定法快速测定矿石中钙、镁

试样用盐酸、硝酸、氢氟酸、高氯酸分解,在pH值为6～9时,经六次甲基四胺-铜试剂分离铁、铝、镍、钴、铅、锌、铜、镉、锰等干扰元素后,在pH=10的氨水和氯化铵缓冲溶液中,以酸性铬蓝K-萘酚绿B为指示剂,用EDTA络合滴定法测定钙镁合量;另在氢氧化钾溶液中,用钙试剂为指示剂,以EDTA络合滴定法测定钙量,从而计算镁的含量。当样品钙高镁低或者镁高钙低时,低含量的镁量或钙量(5%)可用电感耦合等离子体原子发射光谱(ICP-AES)法准确测定,使结果更准确。实验中对三个标准样品中的钙和镁进行多次测定,结果与认定值相符,相对标准偏差在0.69%～1.3%(n=7),加标回收率在99%～102%。方法实用性强,已经成功应用于各类矿石中钙镁的检测。     

EDTA络合滴定法快速测定矿石中钙、镁

试样用盐酸、硝酸、氢氟酸、高氯酸分解,在pH值为6～9时,经六次甲基四胺-铜试剂分离铁、铝、镍、钴、铅、锌、铜、镉、锰等干扰元素后,在pH=10的氨水和氯化铵缓冲溶液中,以酸性铬蓝K-萘酚绿B为指示剂,用EDTA络合滴定法测定钙镁合量;另在氢氧化钾溶液中,用钙试剂为指示剂,以EDTA络合滴定法测定钙量,从而计算镁的含量。当样品钙高镁低或者镁高钙低时,低含量的镁量或钙量(<5%)可用电感耦合等离子体原子发射光谱(ICP-AES)法准确测定,使结果更准确。实验中对三个标准样品中的钙和镁进行多次测定,结果与认定值相符,相对标准偏差在0.69%～1.3%(n=7),加标回收率在99%～102%。方法实用性强,已经成功应用于各类矿石中钙镁的检测。     

电感耦合等离子体发射光谱(ICP-OES)法测定橘子汁中钙和镁

建立了微波消解和湿法消解对样品进行前处理,电感耦合等离子体发射光谱法(ICP-OES)测定橘子汁样品中钙和镁含量的方法。选择Ca 317.933nm,Mg 285.213nm作为钙和镁的分析线。实验结果表明,钙和镁的检出限分别为0.001 8和0.000 4mg/L,相对标准偏差(RSD2%),加标回收率为99%~101%,用来测定FAPAS国际比对橘子汁样品,反馈的统计结果显示钙和镁元素的Z值分别为-0.3和0.3,结果均为满意。方法快速、简单、精确,适于橘子汁中钙和镁的测定。     

电感耦合等离子体原子发射光谱法测定植物中钾、钠、钙和镁

采用硝酸–高氯酸湿法消解或硝酸–双氧水微波消解植物样品,以电感耦合等离子体原子发射光谱法同时测定样品溶液中钾、钠、钙和镁含量。用该法测定灌木枝叶和茶叶标准样品,测定值均在标准值范围内,测定结果的相对标准偏差为0.45%~4.05%(n=8)。钾、钠、钙、镁的加标回收率分别为94.4%~107.6%,92.6%~107.9%,93.7%~105.4%,92.9%~107.2%。该方法操作简便,测量精密度和准确度完全满足植物中钾、钠、钙和镁含量的测定要求。     

褶合曲线分析法同时测定血清中镁和钙

应用计算机辅助褶合曲线分析法和计算机信息处理技术 ,无需分离和掩蔽 ,同时测定了血清中的镁与钙。血清中镁和钙的平均加标回收率和相对标准偏差 (n=5 )分别为 99.0 7% ,2 .32 %和 98.33% ,2 .5 8%     

次灵敏线火焰原子吸收光谱法测定镍镁合金中镁

以镁的202.5nm次灵敏线为分析线,火焰原子吸收光谱法测定镍镁合金中的镁含量。样品以硝酸(1+1)溶解,采用氯化锶为释放剂,以消除共存元素的干扰。在优化的实验条件下,方法的相对标准偏差小于3%,样品加标回收率为95.0%～105.5%。结果表明采用镁的次灵敏线测定镍镁合金中的镁含量,其精密度和准确度均能达到分析要求,可满足日常检测的需求。     

小花玄参中微量金属元素分析

采用干式灰化法分解样品,火焰原子吸收光谱法测定小花玄参不同部位中微量金属元素含量.小花玄参不同部位均含有钙、铁、锰、镁、铜和锌等微量金属元素,其中钙、铁、锰的含量较高,锌、镁的含量较低;6种微量金属元素在块根中含量均高于茎叶;加标回收率在95.3%~104.1%之间,相对标准偏差小于2%,具有较高的精密度与准确度.为小花玄参的质量控制和开发利用提供了重要依据.     

电感耦合等离子体发射光谱法测定湿法精制磷酸中镁、钙、铁、砷含量

采用电感耦合等离子体发射光谱法(ICP-OES)测定湿法精制磷酸中微量元素镁、钙、铁、砷含量,对仪器参数及元素谱线等相关参数进行实验和优化,方法具有线性范围宽、精密度高、结果准确、分析速度快等特点。相对标准偏差RSD为0.26%～0.82%,加标回收率为95.75%～102.8%,检出限为0.0021～0.0408mg/L,适用于湿法精制磷酸中镁、钙、铁、砷的测定。     

沈阳市学龄前儿童末梢血矿物质检测结果分析

为了解沈阳市学龄前儿童体内矿物质钙、铁、锌、铜、镁的含量与年龄和性别的关系,探讨防治其缺乏的综合措施,利用BH 5100型原子吸收光谱仪对3483例学龄前儿童末梢血中铜、锌、钙、镁和铁元素进行了检测,采用SPSS 17．0软件进行统计分析。结果表明,该地区学龄前4个不同年龄组儿童末梢血锌、钙、铁、铜元素缺乏严重,分别占总样本的66．90％、39．76％、32．5％和26．87％;3～岁组末梢血中钙、铁、锌、镁含量与其它年龄组比较差异有统计学意义（P〈0．05）,各元素在性别问差异无统计学意义（P〉0．05）。该地区学龄前儿童钙、铁、锌、铜失衡明显,应加强营养素的合理搭配及矿物质的补充,保证儿童的健康成长。     

Ion-Selective Electrode Determination of Calcium and Potassium in Bovine Skim-Milk Powder

Abstract

Ion-selective electrode determinations of potassium and calcium have been carried out on skim milk powder and the results compared with data obtained by flame emission spectroscopy for potassium and by atomic absorption spectroscopy for calcium. The data indicate that ion-selective electrodes can be used as an alternative to spectroscopic methods for determining these metals by using a dry-ashing pretreatment procedure. Acid digestion pretreatment is not recommended because of the ensuing high ionic strength and possible interferences. Sodium and magnesium contents obtained by spectroscopy are also quoted for interest. The various percentage metal contents are: potassium: 1.96 ± 0.155 (ISE direct) 1.81 ± 0.144 (ISE Gran) and 1.82 ± 0.076 (flame emission), sodium: 0.511 ± 0.017 (flame emission), calcium: 1.37 ± 0.095 (ISE direct), 1.36 + 0.079 (ISE Gran) and 1.41 ± 0.082 (flame aas), and magnesium 0.119 ± 0.003 (flame aas).     

Determination of Mineral Elements in Milk Products by Inductively Coupled Plasma-Optical Emission Spectrometry

The determination of mineral elements in milk products is of great importance since their excess or deficiency may affect human health. In this study, calcium, magnesium, potassium, sodium, phosphorus, and iron were determined in milk products from South Korea. The samples were wet-digested by microwave-assisted combustion using nitric acid and hydrogen peroxide, and analyzed by inductively coupled plasma-optical emission spectrometry. The method was validated by sensitivity, linearity, precision, recovery checks, and the analysis of a milk powder certified reference material. The elemental concentrations were similar in the milk products. Calcium and potassium were the most abundant, followed by phosphorus, sodium, magnesium, and iron. All concentrations were comparable to previous values and were within the limits of recommended dietary allowances and tolerable upper levels.     

Determination of calcium in silicate rocks by potentiometric titration with ethyleneglycol-bis-(2-Aminoethylether)tetraacetic acid and a calcium-selective electrode

The method reported for the determination of calcium in silicate rocks involves titration with ethyleneglycol-bis(2-aminoethylether)tetraacetic acid (EGTA) to a potentiometric end-point. A Crytur calcium-selective electrode is used; the selectivity constants (K_ca,x) are less than 10^-3 for Mg, Ba, Sr, K and Na. The method can be used for calcium contents of 2% or higher (and exceptionally for lower contents), in the presence of up to 60% Mg, 33% AI, 17% Fe, 5% Ba, 5% Ti, and 2.5% Mn. Al, Fe and Ti are masked with sulphosalicylic acid, barium is precipitated as its sulphate, and manganese is bound as its cyanide complex. If the magnesium content is less than that of calcium, EDTA can be used as titrant, magnesium being masked with acetylacetone.     

Effect of temperature on the salt balance of milk studied by capillary ion electrophoresis

Many inorganic species, such as calcium, phosphate and magnesium, are in equilibrium between the liquid and colloidal phases of milk and hence are of importance with respect to the coagulation properties of milk. Capillary ion electrophoresis makes possible the determination of anions and cations in less than 6 min. The soluble phase of milk was obtained by ultrafiltration and samples had to be diluted 250-fold before analysis. Cold storage increased soluble calcium and phosphate concentrations, and warm-up of the milk restored the initial ionic equilibria. More drastic heat treatments (80–90°C) caused precipitation of tricalcium phosphate and calcium citrate.     

过敏性哮喘患者血清中钙镁钡铝锶含量的研究

３４例过敏性哮喘患者血清中钙、镁、钡、铝、锶的含量与对照组比较，结果显示（１）钙的含量明显下降，Ｐ＜０．０１；（２）钡和锶的含量升高，差异有显著性和高度显著性，Ｐ＜０．０５和Ｐ＜０．０１；（３）镁和铝的含量差异无显著性，Ｐ＞０．０５。     

Determination of calcium, magnesium and zinc in unused lubricating oils by atomic absorption spectroscopy

Varying concentrations of lanthanum and strontium were added to solutions of ashed unused lubricating oils for the determination of calcium, magnesium and zinc content using flame atomic absorption spectrophotometry. At least 3000 μg g⁻¹ of lanthanum or strontium was required to completely overcome the interference of the phosphate ion, PO³⁻₄, and give peak values for calcium. The presence of lanthanum or strontium did not cause an appreciable increase in the amount of magnesium and zinc obtained from the analyses. The method is fast and reproducible, and the coefficients of variation calculated for the elements using one of the samples were 1.6% for calcium, 3.5% for magnesium and 0.2% for zinc. Results obtained by this method were better than those obtained by other methods for the same samples.