Determination of lead, cadmium and mercury in microwave-digested foodstuffs by RP-HPLC with an on-line enrichment technique.

A new method for the simultaneous determination of lead, cadmium and mercury ions in microwave-digested foodstuffs by reversed-phase high-performance liquid chromatography combined with on-line enrichment technique has been developed. The foodstuff samples were digested by microwave digestion. The lead, cadmium and mercury ions can be precolumn derivatized with 5,10,15,20-tetrakis(3-aminophenyl)porphine (T3APP) to form color chelates; then, the Hg-T3APP, Cd-T3APP and Pb-T3APP chelates can be enriched and separated on a valve switching HPLC system combined with on-line enrichment technique. The linearity ranges are 0.01-120 microg/l for each metal ion. The detection limits (S/N = 3) of lead, cadmium and mercury are 1.2 ng/l, 0.5 ng/l and 0.8 ng/l, respectively. This method was applied to the determination of lead, cadmium and mercury in foodstuffs with good results.     

海带吸附法分离富集水样中痕量铅和镉

研究了用海带吸附法分离富集水中痕量Pb2 和Cd2 的方法.在25℃下,pH4.0～5.0,水样经过预先用海带制成吸附柱后,用10mL 1 mol/L的HCl,流速为1 mL/min对吸附柱进行洗脱,采用原子吸收光谱法测定洗脱液中Pb2 和Cd2 .Pb2 和Cd2 的饱和吸附量分别为164.67和8.73 mg/g,回收率在95.8%～103.1%之间.     

Determination of copper,nickel, cobalt,silver, lead,cadmium, and mercury ions in water by solid-phase extraction and the RP-HPLC with UV-Vis detection

A new method for the simultaneous determination of seven heavy metal ions in water by solid-phase extraction and reversed-phase high-performance liquid chromatography (RP-HPLC) was developed. The copper, nickel, cobalt, silver, lead, cadmium, and mercury ions were pre-column derivatized with tetra( m-aminophenyl)porphyrin (T m-APP) to form colored chelates. The metal-T m-APP chelates in 100 mL of sample were preconcentrated to 1 mL by solid-phase extraction with a C(18 )cartridge; an enrichment factor of 100 was achieved. The chelates were separated on a Waters Xterra()RP(18) column by gradient elution with methanol (containing 0.05 mol L(-1) pyrrolidine-acetic acid buffer salt, pH 10.0) and acetone (containing 0.05 mol L(-1) pyrrolidine-acetic acid buffer salt, pH 10.0) as mobile phase at a flow rate of 1.0 mL min(-1) and detected with a photodiode array detector. The detection limits of copper, cobalt, nickel, silver, lead, cadmium, and mercury are 2, 2, 3, 4, 3, 3, and 3 ng L(-1), respectively, in the original sample. The method was also applied to the determination of these metals in water with good results.     

能量色散-X射线荧光光谱测定中草药痕量镉、铅、铜

为寻求一种能够直接对中草药中重金属进行快速检测的方法,采用压片法对样品进行前处理,建立了能量色散-X射线荧光光谱法快速检测中草药中痕量重金属镉、铅、铜元素的方法。在20 min即可完成检测,镉、铅、铜检出限分别为0.072、0.207、0.340 mg/kg,测试结果表明与原子吸收和ICP-MS相比,本方法数据稳定性和准确度良好,具有快速、准确、简单的优点,能够满足药典中对重金属元素的限量要求,适用于现场快速检测与质量控制检测。     

大体积进样-浓缩柱在线富集-离子色谱法测定水中痕量及超痕量溴酸盐

建立了一种测定水中痕量及超痕量溴酸盐的在线富集大体积进样离子色谱法。采用实验室常备的柱容量较高的Dionex IonPac AG23保护柱作为浓缩柱,连接在定量环处富集溴酸盐。淋洗液自动发生装置在线生成高纯度氢氧化钾淋洗液进行梯度洗脱,抑制电导检测。实验结果表明:溴酸盐质量浓度范围在0.05~51.2 μg/L之间时线性关系良好,相关系数r≥0.9995,方法检出限为0.01 μg/L。与常规进样相比,进样量可高达5 mL,浓缩因子约为240倍。本方法成功应用于市售纯净水中溴酸盐的测定,2个加标水平的回收率在90%~100%之间,RSD(n=6)为2.1%~6.4%。该方法无需前处理,操作简单,准确度和精密度良好。通过大体积进样实现高倍富集,适用于痕量及超痕量溴酸盐的分析。     

Separations involving sulphides : Separation of (a) bismuth,lead and cadmium from mercury,and (b) bismuth and mercury from indium

It has been shown that 2N sodium sulphide reagent can be successfully used in the seperation and estimation of: (a) bismuth, lead and cadmium from mercury, and (b) bismuth and mercury from indium     

低压微波消解——ICP-AES法测定聚氯乙烯塑料及其制品中的Pb、Cd、Cr和Hg

采用低压微波消解系统, 以HNO3、HCl、H2O2、HClO4和HF消解样品, 用H3BO3络合过量的F-, 并研究了Cl-对测汞的影响、共存元素的干扰、H3BO3对各元素的影响, 建立了低压微波消解─ICP-AES法测定聚氯乙烯塑料及其制品中Pb、Cd、Cr和Hg的方法. Pb、Cd、Cr和Hg的检出限(3σ)分别为: 0.012、0.002、0.006、0.020 μg/mL, 相对标准偏差为0.5%～4.0%, 回收率为95%～101%. 该方法可推广应用到其它塑料中Pb、Cd、Cr和Hg的测定, 已应用于实际的检测工作.     

Simultaneous determination of palladium, platinum and rhodium by on-line column enrichment and HPLC with 5-(2,4-dihydroxyphenylazo)-rhodanine as pre-column derivatization reagent

In this paper, a new method for the simultaneous determination of palladium, platinum and rhodium ions was developed using a rapid column high performance liquid chromatography equipped with on-line enrichment technique. The palladium, platinum and rhodium ions were pre-column derivatized with DHAR to form colored chelates. The Pb-DHAR, Pt-DHAR and Rh-DHAR chelates could be absorbed onto the front of the enrichment column when they were injected into the injector and sent to the enrichment column [ZORBAX Stable Bound, 4.6 x 10 mm, 1.8 microm] with a 0.05 mol L(-1) of phosphoric acid solution as mobile phase. After enrichment, and by switching the six ports switching valve, the retained chelates were back-flushed by mobile phase and traveling towards the analytical column. The separation of these chelates on the analytical column [ZORBAX Stable Bound, 4.6 x 50 mm, 1.8 microm] was satisfactory with 54% acetonitrile (containing 0.05 mol L(-1) of phosphoric acid and 0.1% of tritonX-100) as mobile phase. Palladium, platinum and rhodium were separated completely within 2 min. By on-line enrichment technique, the enrichment factor of 100 was achieved, and the detection limits (S/N = 3) of palladium, platinum and rhodium reaches 1.4 ng L(-1), 1.6 ng L(-1) and 2.0 ng L(-1), respectively. This method was applied to the determination of palladium, platinum and rhodium in water, urine and soil samples with good results.     

催化动力学光度法同时测定痕量铅和镉

在十六烷基三甲基溴化铵（CTAB）存在下，痕量的Pb(Ⅱ）和Cd(Ⅱ）在硼酸－氯化钾－氢氧化钠缓冲体系中，能同时催化过硫酸铵氧化焦锫酚红（PR）而发生褪色指示反应，通过研究该反应的最佳反应条件以及将多元线性回归（MIR）用于数据处理，建立了同时测定铅和镉的新方法，方法已用于废水及铜混中铅和镉的同时测定。     

Determination of palladium,platinum, and rhodium by HPLC with online column enrichment using 4-carboxylphenyl-thiorhodanine as a precolumn derivatization reagent

In the present work, 4-carboxylphenyl-thiorhodanine (CPTR) was synthesized. A new method for the simultaneous determination of palladium, platinum, and rhodium ions as metal-CPTR chelates was developed using rapid column high-performance liquid chromatography equipped with an online enrichment capability. Palladium, platinum, and rhodium ions were precolumn-derivatized with CPTR to form colored chelates. The Pd-CPTR, Pt-CPTR, and Rh-CPTR chelates can absorbed onto the front of the enrichment column (ZORBAX Stable Bound, 4.6 × 10 mm, 1.8 μm) when they are injected with a buffer solution of 0.05 M sodium acetate-acetic acid (pH 3.5) as mobile phase. After the enrichment had finished, by switching the six-port switching valve, the retained chelates were back-flushed by mobile phase and moved towards the analytical column. The chelate separation on the analytical column (ZORBAX Stable Bound, 4.6 × 50 mm, 1.8 μm) was achieved with 46% acetonitrile (containing 0.05 M of pH 3.5 sodium acetate-acetic acid buffer and 0.01 M tritonX-100) as mobile phase. The palladium, platinum, and rhodium were separated completely within 2 min. The detection limits (S/N = 3) of palladium, platinum, and rhodium are 1.4, 1.6, and 2.0 ng/L, respectively. The method was applied to the determination of palladium, platinum, and rhodium in water, urine, and soil samples with good results. The text was submitted by the authors in English.     

Extractive separation of trace amounts of mercury, cadmium and zinc

A simple solvent extraction procedure is reported for the sequential separation of mercury(II), cadmium(II) and zinc(II). Mercury is separated first using 1,3-diphenyl-2-thiourea in chloroform at an overall acidity of 0.3M HCl. Then cadmium separated using the same reagent at pH 10 into dichloromethane. The zinc which is remaining in the aqueous phase is then quantitatively extracted into toluene-cyclohexanol mixture using 2-mercaptobenzoxazole. Suitable stripping solutions have been proposed for the re-extraction of these metal ions for their subsequent estimations. The method has been made highly selective by the use of appropriate masking agents and has been applied in conjunction with estimation procedures for the determination of these metal ions in city waste incineration ash (CRM 176), mercuric chloride (A. R. grade) and in magnesium alloy samples.     

Determination of cadmium, lead and copper in water samples by flame atomic-absorption spectrometry with preconcentration by flow-injection on-line sorbent extraction

Cadmium, lead and copper were determined in synthetic sea-water, drinking water and the NBS 1643b Trace Elements in Water standard reference material at mug/l. levels by flame atomic-absorption spectrometry after on-line preconcentration by sorbent extraction with a flow-injection system. Bonded silica with octadecyl functional groups packed in a micro column of 100 mul capacity was used to collect diethylammonium diethyldithiocarbamate complexes of the heavy metals in the aqueous samples. The sample loading time was 20 sec at a flow-rate of 3.3 ml/min. Ethanol or methanol was used to elute the adsorbed analytes into the spectrometer. The sample loading rate, elution rate and pH were optimized. Enrichment factors of 19-25 for Cd, Pb and Cu were achieved at sampling frequencies of 120/hr with precisions of 1.4, 1.0 and 1.3% rsd (n = 11), respectively. The detection limits (3sigma) for Cd, Pb and Cu were 0.3, 3 and 0.2 mug/l., respectively. Determination of Cd, Pb and Cu in NBS SRM 1643b showed good agreement with the certified values. Recoveries of Cd and Pb added to sea-water were 95 and 102%, respectively.     

Determination of cadmium,mercury and lead in seawater by electrothermal vaporization isotope dilution inductively coupled plasma mass spectrometry

Electrothermal vaporization isotope dilution inductively coupled plasma mass spectrometry (ETV-ID-ICP-MS) has been applied to the determination of Cd, Hg and Pb in seawater samples. The isotope ratios of the elements studied in each analytical run were calculated from the peak areas of each isotope. Various modifiers were tested for the best signal of these elements. After preliminary studies, 0.15% m/v TAC and 4% v/v HCl were added to the sample solution to work as the modifier. The ETV-ID-ICP-MS method has been applied to the determination of Cd, Hg and Pb in NASS-4 and CASS-3 reference seawater samples and seawater samples collected from Kaohsiung area. The results for reference sample NASS-4 and CASS-3 agreed satisfactorily with the reference values. Results for other samples determined by isotope dilution and method of standard additions agreed satisfactorily. Detection limits were approximately 0.002, 0.005 and 0.001 ng ml⁻¹ for Cd, Hg and Pb in seawater, respectively, with the ETV-ICP-MS method. Precision between sample replicates was better than 20% for most of the determinations.     

Determination of traces of lead and cadmium using dispersive liquid-liquid microextraction followed by electrothermal atomic absorption spectrometry

Microchimica Acta - A procedure is presented for the determination of very low concentrations of lead and cadmium in water samples. Dispersive liquid-liquid microextraction with ammonium...     

Separation and determination of trace amounts of beryllium(II), aluminium(III) and chromium(III) with chromotrope 2C chelates by RP-HPLC

A reversed-phase high-performance liquid chromatographic separation and determination of beryllium(II), aluminium(III) and chromium(III) with chromotrope 2C chelates on a C18-bonded stationary phase is reported. Methanol-water (45:55 v/v) containing 6 x 10(-3)M tetra-n-butylammonium bromide (TBAB) and 2 x 10(-2)M acetate buffer solution (pH 6.0) as mobile phase and with spectrophotometric detection at 530 nm was applied. The method has high sensitivity, the detection limits being 0.2 ppb for beryllium(I), 1 ppb for aluminium(III) and 2 ppb for chromium(III). Under the optimum conditions, most other metal ions did not interfere, e.g. up to 2 mg of Hg(II), Sn(II, IV), Pb(II), Bi(III), Ag(I), Zn(II), Cd(II), Cu(II), 1.5 mg of Fe(II), Co(II), Ni(II), 1.2 mg of Ca(II), Mg(II), Sr(II), Ba(II), 1 mg of Ga(III), In(III), 0.5 mg of Fe(III), 1 mg of Ga(III), In(III), 0.5 mg of Fe(III), 0.4 mg of Th(IV), Zr(IV). The method can be applied to the simultaneous determination of trace amounts of beryllium(II), aluminium(III) and chromium(III), in water, rice, flour and human hair samples.     

Determination of trace amounts of cadmium, lead, copper and zinc in natural waters by inductively coupled plasma atomic emission spectrometry with thermospray nebulisation, after enrichment on Chelex-100

Enrichment on Chelex-100, followed by evaporation when necessary, was used for the pre-concentration of Cd, Pb, Cu and Zn from natural waters. The measurements were carried out with inductively coupled plasma atomic emission spectrometry using a thermospray nebulisation system to reach the required sensitivity. The detection limits corresponding to three times the standard deviation of the blank (in 1% v/v HNO3) after a 30-fold enrichment are 0.02 microgram l-1 for Cd, 0.33 microgram l-1 for Pb and 0.03 microgram l-1 for Cu and Zn. Matrix effects, which are fairly serious with thermospray nebulisation, were taken into account by using the standard additions method. Results obtained for several river water samples were compared with those found by analysis of the non-enriched sample with inductively coupled plasma mass spectrometry or graphite furnace atomic absorption spectrometry. In all instances the agreement was satisfactory.     

Separation and determination of trace amounts of zinc, lead, cadmium and mercury in tap and Qaroun lake water using polyurethane foam functionalized with 4-hydroxytoluene and 4-hydroxyacetophenone

A stable chelating sorbent was synthesized by covalently linking 4-hydroxytoluene or 4-hydroxyacetophenone with the polyurethane foam (PUF) through -NN- group. The synthesized chelating sorbents were characterized by IR and UV/vis measurements. The modified foams show excellent stability towards various solvents. Factors influencing the extraction process of Zn(II), Pb(II), Cd(II) and Hg(II) were studied and evaluated as a function of pH of metal ion solution and equilibration shaking time. The values of sorption capacity of metal ions (μg g⁻¹) were determined with the two types of bonded foams. The two phenolic bonded foams were studied comparatively. The potential applications of the two newly synthesized foams for the removal and separation of the examined metal ions from two natural water samples (drinking tap water and Qaroun lake water at Fayoum City, Egypt) were investigated. Precision (assessed as a relative standard deviation, R.S.D.) was also evaluated and found to be ≤7.3% (N = 5) with a detection limit under 0.46 μg L⁻¹.     

Determination of mercury,arsenic and cadmium in fish by neutron activation

Determination of mercury, arsenic and cadmium in fish has been carried out by neutron activation followed by chemical separation to remove the interfering activities of copper, zinc, etc. Some of the common varieties of fish have been analysed and their results are presented.     

Determination of trace elements in seawater samples by on-line column extraction/graphite furnace atomic absorption spectrometry

An innovative procedure for the on-line coupling of ion chromatography with graphite furnace atomic absorption spectrometry is described, which is particularly effective for the determination of trace metals in seawater samples. The Capillary Injection Device (CID) is used as an interface which allows the eluent to be transferred from the chromatographic column into the graphite tube at a flow rate of as high as 2 ml/min. The analytical procedure is based on the metal complex formation with 8-hydroxyquinoline in the sample solution, followed by the preconcentration of the complexes in a chromatographic column packed with XAD-2 resin. The complexes were then eluted from the column with methanol, and quantitatively injected into the furnace. The procedure was validated by determining cadmium and lead in certified reference seawater samples at a level of 30–40 pg/g, with a typical reproducibility of 10% and an accuracy of better than 5%. Finally, it was tested on a real sample of seawater. Due to the high reproducibility, a pg/g concentration level can be measured.     

低压微波消解─ICP-AES法测定聚氯乙烯塑料及其制品中的Pb、Cd、Cr和Hg

采用低压微波消解系统,以HNO3、HCl、H2O2、HClO4和HF消解样品,用H3BO3络合过量的F-,并研究了Cl-对测汞的影响、共存元素的干扰、H3BO3对各元素的影响,建立了低压微波消解─ICP-AES法测定聚氯乙烯塑料及其制品中Pb、Cd、Cr和Hg的方法。Pb、Cd、Cr和Hg的检出限(3σ)分别为:0.012、0.002、0.006、0.020μg/mL,相对标准偏差为0.5%~4.0%,回收率为95%~101%。该方法可推广应用到其它塑料中Pb、Cd、Cr和Hg的测定,已应用于实际的检测工作。