火焰原子吸收光谱法测定红土镍矿中铜、锌、铬含量

红土镍矿样品用盐酸、硝酸分解,残渣用焦硫酸钾熔融,在稀盐酸介质中,采用氘灯扣除背景,分别用原子吸收光谱仪于波长324.8,213.9,357.9 nm处,使用空气–乙炔火焰,测量铜、锌、铬的含量。在最佳实验条件下,铜、锌、铬的质量浓度分别在0.50～2.50,0.30～1.50,0.50～4.50 mg/L范围内与吸光度线性关系良好,相关系数r分别为0.9986,0.9943,0.9942。方法检出限铜为0.0067 mg/L,锌为0.0010 mg/L,铬为0.0014 mg/L,加标回收率为95.0%～105.7%。精密度试验验证铜、锌、铬的含量分别在0.01%～0.50%,0.01%～1.00%,0.01%～4.00%范围内重复性和再现性较好。此方法适合于红土镍矿中铜、锌、铬含量的测定。     

ICP-AES法测定合金粉中的镍、铬、钴、铝和钇含量

采用ICP-AES法,直接测定合金粉中的Ni,Cr,Co,Al和稀土元素Y,优选了适宜的仪器测定参数和合适的分析谱线.研究了基体效应、共存元素间干扰及干扰校正方法,通过对实际样品的实验,测得Ni,Cr,Co,Al,Y检出限为10,10,8,10,3 μg·L-1;回收率96.5%,95.7,97.0%,97.9%,97.6%;RSD为1.06%,0.77%,0.70%,0.94%,0.50%.     

ICP-AES法测定铜镍矿、铅锌矿中铜、镍、铅、锌、钴

用电感耦合等离子体发射光谱法测定铜镍矿、铅锌矿石中铜、镍、铅、锌、钴,样品用盐酸-硝酸溶解,在选定的测量条件下以ICP-AES测定溶液中的Cu、Pb、Zn、Co、Ni的含量.对国家一级标准物质进行测定,方法精密度(RSD,n=12)为Cu 2.92%～6.62%,Pb 1.88%～2.61%,Zn 1.30%～2.05%,Co 6.90%,Ni 2.23%.本方法具有线性范围宽、干扰少、快速、简便、检出限低等优点.用于实际使用,结果满意.     

低温密封消解ICP-OES法测定烤鳗中的钙、铁、锌、铜、锰、镁

采用低温密封消解烤鳗样品后,用ICP-OES法测定烤鳗中的Ca、Fe、Zn、Cu、Mn、Mg等微量元素的含量,并对消化样品所用酸的量、元素分析线的选择以及共存元素间的干扰进行了研究。该法可以同时测定烤鳗中多种营养元素,且简便快速,精密度和准确度都较好。     

ICP-AES法测定铜磁铁矿中铜、锰、铝、钙、镁、钛和磷量

通过样品处理、干扰试验、方法检出限、准确性和精密度试验,确定了最佳实验条件,建立了电感耦合等离子体-原子发射光谱法测定铜磁铁矿中铜、锰、铝、钙、镁、钛和磷含量的方法。试料经盐酸、硝酸、氢氟酸、高氯酸分解,用盐酸溶解盐类,过滤,采用电感耦合等离子体发射光谱法同时测定滤液中铜、锰、铝、钙、镁、钛和磷量。方法检出限：锰、钛和磷小于0.00085%,其它元素小于0.0054%,分析结果与分光光度法、XRF法和AAS法分析结果一致,8个实验室对5个水平样品进行协同试验给出了方法的精密度。     

ICP-AES法测定发菜中铜铁锰锌硼镍

发菜（Nostoc flgelliforme）是一种野生的陆生澡类植物,属于念珠藻属。我国主要产于内蒙古、宁夏、新疆、甘肃、青海等地,是传统的出口商品。以前对发菜微量元素分析多采用化学法等,试剂用量多,干扰比较大,而采用电感耦合等离子体光谱法（ICP-AES）,方法简便、快速、准确。本法选择HNO3-H2SO4-HClO4体系消化样品,使用ICP-AES法测定,回收率为91．9％-110．2％。     

ICP-AES法测定饲料中钙、磷含量

采用干灰化法处理饲料样品,以全谱直读ICP—AES法对饲料中钙、磷元素进行了测定。结果表明,该法测定钙的相对标准偏差为0．18％～0．76％,测定磷的相对标准偏差为0．37％～1．02％;钙元素的加标回收率为99．6％-100．3％,磷元素的加标回收率为97．8％-100．5％;该法与国家标准比对,结果准确可靠。     

微波消解ICP-AES法测定高速工具钢中锰、磷、镍、铜、铬、钒

高速工具钢为高碳高合金工具钢,常温下样品酸溶分解较为困难。本文利用微波消解提高溶样的温度和压力,在王水、氢氟酸和硫酸介质中使样品充分消解,再用饱和硼酸溶液络合过量的氢氟酸,基体匹配消除铁基体的影响,ICP-AES法同时测定锰、磷、镍、铜、铬、钒的含量。测定高速工具钢标样,测定值与标样值相吻合,本方法的精密度在0.55%～4.06%。加标回收率在95.6%～114.8%,满足测定要求。     

ICP-AES法测定铜精矿中As、Sb、Bi、Ca、Mg、Pb、Co、Zn和Ni

提出采用ICP-AES法同时测定铜精矿中As、Sb、Bi、Ca、Mg、Pb、Zn、Ni、Co的分析方法:样品经王水 HF HClO4溶液后,直接测定。该方法测定As、Sb、Bi、Ca、Mg、Pb、Zn、Ni、Co的回收率在97.9%~102%之间,相对标准偏差在0.23%~2.5%之间。通过和国家标准物质比对及国家标准分析方法的比对,结果准确可靠,现该方法已用于本公司铜精矿的日常分析。     

热解齐化-原子吸收光谱法测定红土镍矿中汞含量

经过条件试验,建立了热解齐化-原子吸收光谱法直接测定红土镍矿中汞含量的方法。样品中汞含量在57～1752μg／kg,重复测定的相对标准偏差（RSD）在1．6％～5．3％（n=11）,回收率在92．79％～94．77％,与冷原子吸收光谱法的方法间相对偏差为5．18％～11．93％。方法准确、快速、样品用量少、无试剂污染,适合于批量样品的测试,有应用和推广价值。     

Determination of Zn, B, Fe, Mg, Ca, Na and Si in anisette samples by inductively coupled plasma atomic emission spectrometry

A comparative study of several digestion methods of anisette samples has been carried out. Two dry ashing (DA) treatments as well as four wet ashing (WA) procedures using different mixtures of acids were applied for the sample mineralisation before analysis. Once the anisette samples were mineralised, the contents of Zn, B, Fe, Mg, Ca, Na and Si were determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES). Each method has been studied statistically and also attending to their feasibility. After performing the optimisation of the different treatments tested, it was concluded that one wet ashing method employing a HNO₃:H₂O₂ (10:1) mixture was the most suitable. This method was applied to the analysis of anisette samples. Na, Ca, Mg and Si were present in concentrations up to 215 mg l⁻¹ for Na, 11.6 for Mg, 6.2 for Ca and 5.1 for Si. Fe and B concentrations were not higher than 0.12 mg l⁻¹ and lower for Zn.     

电热石墨消解ICP-OES测定土壤中铜锌镍铬

采用电热石墨消解仪消解土壤样品,以电感耦合等离子体发射光谱法(ICP-OES)测定土壤样品中铜、锌、镍、铬4种元素。分别从消解液的种类、用量及样品消解量等方面进行实验条件的优化,确定了一个最适合土壤消解的前处理过程。各元素的检出限为Cu 0.54 mg/kg,Cr 0.42 mg/kg,Zn 0.62 mg/kg,Ni 0.58 mg/kg,回收率为96.5%～104.0%,测定结果的相对标准偏差为0.7%～2.1%(n=7)。     

On-line preconcentration and simultaneous determination of heavy metal ions by inductively coupled plasma-atomic emission spectrometry

A flow injection analysis system for on-line preconcentration and simultaneous determination of Bi³⁺, Cd²⁺, Co²⁺, Cu²⁺, Fe³⁺, Ni²⁺, Pb²⁺ and Zn²⁺ in aqueous samples by inductively coupled plasma (ICP)-atomic emission spectrometry with a charge coupled detector is described. The preconcentration of analytes is accomplished by retention of their chelates with sodium diethyldithiocarbamate in aqueous solution on a solid phase containing octadecyl silica in a minicolumn. Methanol, as eluent, is introduced into the conventional nebulizer of the ICP instrument. The effects of different parameters, including preconcentration flow rate (equal to sample flow rate (SR)), eluent flow rate (ER), weight of solid phase (W) and eluent loop volume (EV), were optimized by the super-modified simplex method. The optimum conditions were evaluated to be SR 7.2 ml min⁻¹, ER 3.5 ml min⁻¹, W of 100 mg and EV of 0.8 ml. An enrichment factor of 312.5 for each analyte was obtained. The detection limits of the proposed method for Bi³⁺, Cd²⁺, Co²⁺, Cu²⁺, Fe³⁺, Ni²⁺, Pb²⁺ and Zn²⁺ were evaluated as 1.3, 1.0, 0.8, 0.3, 14.7, 0.5, 5.5 and 0.1 ng l⁻¹, respectively. The effect of several metal ions on percent recovery was also studied. The method was applied to the recovery of these heavy metals from real matrices and to the simultaneous determination of these cations in different water samples.     

Use of enzymatic hydrolysis for the multi-element determination in mussel soft tissue by inductively coupled plasma-atomic emission spectrometry

A systematic evaluation of different variables affecting the enzymatic hydrolysis of mussel soft tissue by five enzymes, three proteases (pepsin, pancreatin and trypsin), lipase and amylase, has been carried out for the determination of trace elements (As, Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) by inductively coupled plasma-atomic emission spectrometry (ICP-AES). Enzymatic hydrolysis methods offers advantages such as a less species alteration, safer laboratory conditions and a less contaminant wastes. The enzymatic hydrolysis was performed in an incubation camera Boxcult with orbital and horizontal shaker. Variables affecting the enzymatic hydrolysis process were simultaneously studied by applying a Plackett-Burman design (PBD). For a confidence interval of 95%, the significant factors for all enzymes and for most of the elements were the pH, the incubation temperature and the ionic strength. These significant factors were optimized later by using a central composite design (CCD), which gave optimum conditions at pH of 1, incubation temperature of 37 °C and ionic strength fixed by sodium chloride at 0.2 M when using pepsin. For pancreatin, trypsin, lipase and amylase there were found two different optimum condition sets. The first one involves the use of a 0.5 M phosphate buffer (ionic strength), at a pH of 6 and at an incubation temperature of 37 °C, which allows the quantitative extraction of Al, Cr, Mn, Pb and Zn. The second conditions set employees a 0.1 M phosphate buffer (ionic strength), a pH of 9 and an incubation temperature at 37 °C, and it results adequate to extract As, Cd, Cu, Fe and Ni. Analytical performances, repeatability of the over-all procedure and accuracy, by analyzing DORM-1, DORM-2 and TORT-1 certified reference materials, were finally assessed for each enzyme. Good agreement with certified values has been assessed for most of the elements (As, Cd, Cr, Cu, Mn, Ni, Pb and Zn) when using trypsin, pepsin and/or pancreatin, except for Cd and Pb in DORM-1 and DORM-2 because of the certified contents in such certified reference materials are lower than the limit of detection (0.10 and 0.16 μg g⁻¹ for Cd and Pb, respectively, for the use of trypsin).     

In-situ determination of cross-over point for overcoming plasma-related matrix effects in inductively coupled plasma-atomic emission spectrometry

A novel method is described for overcoming plasma-related matrix effects in inductively coupled plasma-atomic emission spectrometry (ICP-AES). The method is based on measurement of the vertically resolved atomic emission of analyte within the plasma and therefore requires the addition of no reagents to the sample solution or to the plasma. Plasma-related matrix effects enhance analyte emission intensity low in the plasma but depress the same emission signal at higher positions. Such bipolar behavior is true for all emission lines and matrices that induce plasma-related interferences. The transition where the enhancement is balanced by the depression (the so-called cross-over point) results in a spatial region with no apparent matrix effects. Although it would be desirable always to perform determinations at this cross-over point, its location varies between analytes and from matrix to matrix, so it would have to be found separately for every analyte and for every sample. Here, a novel approach is developed for the in-situ determination of the location of this cross-over point. It was found that the location of the cross-over point is practically invariant for a particular analyte emission line when the concentration of the matrix was varied. As a result, it is possible to determine in-situ the location of the cross-over point for all analyte emission lines in a sample by means of a simple one-step sample dilution. When the original sample is diluted by a factor of 2 and the diluted sample is analyzed again, the extent of the matrix effect is identical (zero) between the original sample and the diluted sample at one and only one location — the cross-over point. This novel method was verified with several single-element matrices (0.05 M Na, Ca, Ba and La) and some mixed-element matrices (mixtures of Na–Ca, Ca–Ba, and a plant-sample digest). The inaccuracy in emission intensity due to the matrix effect could be as large as − 30% for conventional measurements in the normal analytical zone, but is reduced to within 5% with this new method. The major currently known limitation is that the accuracy of the method is highly sensitive to fluctuations and noise in the vertical emission-intensity profile, so the stability of the ICP system must be controlled to preferably within 1%.     

ICP–AES法测定铬镍不锈钢中锰、铬、镍、硅、磷、铜、钼的含量

建立电感耦合等离子体原子发射光谱(ICP–AES)法测定铬镍不锈钢中锰、铬、镍、硅、磷、铜、钼7种元素含量的方法。试样用盐酸与硝酸混合酸溶液溶解,采用溶解国家标准样品的方法制备校准曲线溶液,确定了元素最佳分析谱线。各元素的含量在其测试范围内与原子发射强度呈良好的线性关系,线性相关系数不小于0.999,7种元素的检出限在0.000 3%~0.003 0%之间。该方法应用于铬镍不锈钢标准样品的测定,测定值与认定值相符,测定值的相对标准偏差在0.12%~1.15%之间(n=8)。应用于铬镍不锈钢样品测定时,加标回收率在90%~110%之间。该方法操作简便、迅速,可满足日常铬镍不锈钢中多元素含量的检测需要。     

Volatilization of Cr, Co, Mn and Ni as their pyrrolidinecarbodithioate chelates from electrothermal vaporizer for sample introduction in inductively coupled plasma optical emission spectrometry

Based on gaseous compound introduction as pyrrolidinecarbodithioate chelates of Cr, Co, Mn and Ni by electrothermal vaporization (ETV) in inductively coupled plasma optical emission spectrometry (ICP-OES), a novel method for the determination of trace Cr, Co, Mn and Ni was developed. It was found that in the presence of ammonium pyrrolidinecarbodithioate (APDC) the trace amounts of analytes were vaporized at a low temperature of 1500 °C. The main factors affecting the formation and vaporization of analytes chelates were investigated in detail. Thermal gravimetric analysis of Cr-APDC, Co-APDC, Mn-APDC and Ni-APDC chelates and UV-vis analysis of the sample vapor collected in CHCl₃ after vaporization of their chelates indicated that the analytes were vaporized and transported into ICP as their chelates. Under the optimized conditions, the limits of detection (LOD) (3σ) and the relative standard deviations (R.S.D.) of Cr, Co, Mn and Ni were 0.36, 0.19, 0.073 and 0.32 ng, and 3.9, 4.9, 3.8 and 3.3% (c = 0.5 μg ml⁻¹, n = 7), respectively. By combination with a solvent extraction step, the proposed method had been successfully applied to analysis of Cr, Co, Mn and Ni in the artificial seawater. To evaluate the accuracy of the developed method, two certified reference materials (human hair GBW 09101 and poplar leaves GBW 07604) were also analyzed, and the determined values obtained were in good agreement with the certified values.     

Electrothermal vaporization dynamic reaction cell inductively coupled plasma mass spectrometry for the determination of Fe,Co, Ni,Cu, and Zn in biological samples

Slurry sampling electrothermal vaporization dynamic reaction cell inductively coupled plasma mass spectrometry (ETV-DRC-ICP-MS) has been applied to determine Fe, Co, Ni, Cu, and Zn in biological samples. The influences of instrument operating conditions and slurry preparation on the ion signals were reported. Pd was used as the modifier. The effectiveness of the ETV sample introduction technique and dynamic reaction cell in alleviating various spectral interferences in ICP-MS analysis has been demonstrated. This method has been applied to determine Fe, Co, Ni, Cu, and Zn in NIST SRM 1573a tomato leaves reference material and NRCC DORM-2 dogfish muscle reference material and also real samples such as a tea and a swordfish sample purchased locally. Since the sensitivities of the elements studied in slurry and aqueous solution were different, an analyte addition technique was used for the determinations. The analytical results of the reference materials agreed with the certified values. The precision between sample replicates was better than 6% for all determinations. The method detection limit estimated from analyte addition curves was 0.01, 0.006, 0.007, 0.004, and 0.006 μg g⁻¹ for Fe, Co, Ni, Cu, and Zn, respectively, in the original biological samples.     

Determination of Mo, Zn, Cd, Ti, Ni, V, Fe, Mn, Cr and Co in crude oil using inductively coupled plasma optical emission spectrometry and sample introduction as detergentless microemulsions

A procedure to prepare crude oil samples as detergentless microemulsions was optimized and applied for the determination of Mo, Zn, Cd, Si, Ti, Ni, V, Fe, Mn, Cr and Co by ICP OES. Propan-1-ol was used as a co-solvent allowing the formation of a homogeneous and stable system containing crude oil and water. The optimum composition of the microemulsion was crude oil / propan-1-ol / water / concentrated nitric acid, 6 / 70 / 20 / 4 w/w/w/w. This simple sample preparation procedure together with an efficient sample introduction (using a Meinhard K3 nebulizer and a twister cyclonic spray chamber) allowed a fast quantification of the analytes using calibration curves prepared with analyte inorganic standards. In this case, Sc was used as internal standard for correction of signal fluctuations and matrix effects. Oxygen was used in the nebulizer gas flow in order to minimize carbon building up and background. Limits of detection in the ng g^− 1 range were achieved for all elements. The methodology was tested through the analysis of one standard reference material (SRM NIST 1634c, Residual Fuel Oil) with recoveries between 97.9% and 103.8%. The method was also applied to two crude oil samples and the results were in good agreement with those obtained using the acid decomposition procedure. The precision (n = 3) obtained was below 5% and the results indicated that the method is well suited for oil samples containing low concentrations of trace elements.     

Effect of HF addition on the microwave-assisted acid-digestion for the determination of metals in coal by inductively coupled plasma-atomic emission spectrometry

The microwave-assisted acid-digestion for the determination of metals in coal by ICP-AES was investigated, especially focusing on the necessity of adding HF. By testing five certified reference materials, BCR-180, BCR-040, NIST-1632b, NIST-1632c, and SARM-20, it was found that the two-stage digestion without HF (HNO₃ + H₂O₂ was used) was very effective for the pretreatment of ICP-AES measurement. Both major metals (Al, Ca, Fe, and Mg) and minor or trace metals (Co, Cr, Cu, Mn, Ni, Pb, and Zn) in coal gave good recoveries for their certified or reference values. The possibility of ‘HF-memory effect’ was cancelled by the use of a set of vessels which had been never contacted with HF. Twenty-four Japanese standard coals (SS coals) were analyzed by the present method, and the concentrations of major metals measured by the present method provided very high accordance with those from the authentic JIS (Japanese Industrial Standard) method.