固体进样直接测定法测定铜精矿中汞

建立了固体进样直接测定法测定铜精矿中汞含量的方法。铜精矿样品在测汞仪的分解炉中经300℃干燥和750℃高温热分解后,汞被催化分解为汞原子,于850℃齐化成金汞齐。汞蒸气被氧气流带入单波长光学吸收池,在波长253.7 nm处测量汞的吸光度,采用标准曲线法计算汞量。方法的线性范围分别为0~1.00,0~100μg/mL,线性相关系数为0.9999,检出限分别为0.10,0.04 ng/g。5个汞含量不同的铜精矿样品测定结果的相对标准偏差为2.14%~4.35%(n=11),样品加标回收率为92.00%~104.02%。采用该方法分别对2个铜精矿样品和铜精矿国际标准物质进行测定,测定结果与标准分析方法测定值和标准物质标示值基本一致。该方法简便、快速、准确,可以作为标准方法推广使用。     

用间接法测定硫化物的研究

前人已经报道用汞的冷原子吸收法测定硫化物,利用Hg~(2+)和S~(2-)形成很稳定的化合物,使汞的吸光度值降低,根据其降低的程度来测定硫化物的含量。这种方法简便、灵敏,但对加入的Hg~(2+)量有较大的限制。S_2O_3~(2-)、CN~-、I~-等也有严重干扰,这些离子常与S~(2-)共存于水样中,所以,实际测定时,常需分离这些离子。     

Simultaneous spectrophotometric determination of mercury and palladium with Thio-Michler's Ketone using partial least squares regression and orthogonal signal correction

A simple, novel and sensitive spectrophotometric method was described for simultaneous determination of mercury and palladium. The method is based on the complex formation of mercury and palladium with Thio-Michler's Ketone (TMK) at pH 3.5. All factors affecting on the sensitivity were optimized and the linear dynamic range for determination of mercury and palladium found. The simultaneous determination of mercury and palladium mixtures by using spectrophotometric method is a difficult problem, due to spectral interferences. By multivariate calibration methods such as partial least squares (PLS), it is possible to obtain a model adjusted to the concentration values of the mixtures used in the calibration range. Orthogonal signal correction (OSC) is a preprocessing technique used for removing the information unrelated to the target variables based on constrained principal component analysis. OSC is a suitable preprocessing method for PLS calibration of mixtures without loss of prediction capacity using spectrophotometric method. In this study, the calibration model is based on absorption spectra in the 360-660 nm range for 25 different mixtures of mercury and palladium. Calibration matrices were containing 0.025-1.60 and 0.05-0.50 microg mL(-1) of mercury and palladium, respectively. The RMSEP for mercury and palladium with OSC and without OSC were 0.013, 0.006 and 0.048, 0.030, respectively. This procedure allows the simultaneous determination of mercury and palladium in synthetic and real matrix samples good reliability of the determination.     

Determination of the different states of mercury in seawater near the Vlora and Durres Bays

Because of the toxicity and mobility of organic mercury, there is a need for determination of organic and inorganic mercury at very low concentrations in the environment, especially in seawater. A procedure for extraction and determination of low concentrations of the different states of mercury - total, inorganic, and organic - in seawater, by cold vapour atomic absorption spectroscopy (CVAAS) is described.Inorganic mercury only was directly reduced to the Hg(0) state by tin(II) chloride under strongly acid conditions (H(2)SO(4)) and mercury metal (Hg(0)) was determined by cold vapour atomic absorption spectroscopy. Organic and inorganic mercury were extracted, with toluene, as the bromide derivatives and re-extracted, together, into ammonium chloride solution. Organic mercury was converted into inorganic mercury by thermal digestion at 80-90 degrees C in the presence of strong oxidants. These two states of mercury were determined together as total mercury. Inorganic mercury was measured directly after pre-concentration of the sample by toluene extraction. Toluene dissolved in aqueous phase after re-extraction of the sample was removed by heating for 30 min at 80-90 degrees C. Organic mercury was calculated as the difference between total and inorganic mercury.The sensitivity of the method is 0.0001 ng mL(-1) Hg, depending on sample volume.     

Chemical enhancement method for the determination of mercury by spectrophotometry after iodide extraction

A selective and sensitive spectrophotometric method for the determination of 0.08-2.5 ppb of mercury(II) is described. Mercury is extracted as tetraiodomercury(II)-Cd-phenanthroline ion-pair into benzene and selectively stripped into EDTA. The iodide associated with mercury present in the stripping is oxidized to iodate and then treated with excess iodide to give iodine. The iodine formed is extracted into benzene and equilibrated with iodate in acidic medium in the presence of chloride and Rhodamine 6G for the formation of ICI(-)(2) species and its extraction as ion-pair with Rhodamine 6G. Determination is completed by measuring the absorption of the extract at 535 nm. The coefficient of variation is 1.5% for 10 determinations of 200 ng of mercury. The method has been applied to establish the mercury content of natural waters and chloralkali plant effluent.     

Substoichiometric determination of mercury by neutron activation analysis

A method has been developed for the substoichiometric determination of mercury by thermal neutron activation analysis, based on the selective extraction of the Hg(II)—Bindschedler's Green complex into 1,2-dichloroethane. The method has been applied for the determination of trace amounts of mercury in geological standards such as W-1, GR, Sye-1, and T-1, meteorite Allende de Publito, and biological materials such as kale, IR1 standard tobacco, and human blood serum.     

微波萃取高效液相色谱-冷原子荧光光谱法测定沉积物中甲基汞和无机汞

建立了微波萃取高效液相色谱-冷原子荧光光谱法(MAE-HPLC-CVAFS)测定沉积物中甲基汞(MeHg+)和无机汞(Hg2+)的方法。以0.1%(V/V)2-巯基乙醇为萃取剂,用于沉积物样品中汞形态的萃取,在80℃下萃取8 min,萃取液直接注入HPLC-CVAFS系统分析。在优化条件下,MeHg+和Hg2+的检出限分别为0.58和0.48 ng/g;加标回收率分别为96.2%和95.8%;RSD(n=6)分别为5.7%和4.1%。对标准参考物质(IAEA-405和ERM-CC580)的分析结果与推荐值一致。本方法简单、快速、准确、检出限低,抗干扰能力强,具有很好的实用性和推广价值。     

天然水中痕量无机汞和有机汞的氢化物原子荧光光谱法分析

建立了天然水中溶解的痕量无机汞和有机汞的氢化物原子荧光光谱法分析方法,该方法经标准物质(PACS-1)和加标回收实验研究表明重现性好、准确度高。在此基础上,应用该方法分析了该校人工湖水中的无机汞和有机汞,发现无机汞和有机汞的含量均低于0.1 礸/L。     

天然水体中痕量汞的形态分析方法研究

天然水体中汞的含量仅为ng/L级，不仅难以测出，而且在测定过程中极易受到干扰；利用两次金汞齐的预富集方法与原子荧光法结合的技术，作者建立了天然水体超痕量不同形态汞的准确分析方法；该方法的检出限达到了0．02ng／L，实验平均回收率为101%；该方法也适用于其它低汞含量水样(包括稀释后的污水及化工废水)中汞的形态分析。     

Minimising the risk of some systematic errors by the use of the single vessel principle for cold vapour atomic absorption spectrometric determination of mercury in biological solids

The suitability of the single vessel principle (performing all steps of an analytical procedure in one vessel) for cold vapour atomic absorption spectrometric determination of mercury in biological solids was evaluated. The single vessel method gave a lower mean blank level with better precision, hence lower detection limits, as compared to the conventional method. The determination of total mercury in biological standard reference materials by the single vessel method also produced significantly higher mercury values and better precision than the conventional method. However, the mercury concentrations obtained in certified reference materials by the use of both methods were close to the mean certified values. Moreover, the use of the single vessel method is cost effective, rapid and environment friendly. The use of the single vessel technique is therefore recommended for accurate and reliable determination of mercury in biological solids. Received: 15 December 1997 / Revised: 9 April 1998 / Accepted: 18 April 1998     

Determination of organic and inorganic mercury compounds by reverse-phase high-performance liquid chromatography after extraction of the compounds as their dithizonates

A sensitive and selective method is described for the simultaneous determination of inorganic and organic mercury compounds. The mercury compounds are extracted into toluene or chloroform with dithizone, and the dithizonates are separated by liquid chromatography on an ODS column. Complete resolution was obtained between methylethyl-, phenyl- and inorganic mercury with a mobile phase of THF/methanol (2:1) with 0.05 M acetate buffer pH 4 (62 + 38), containing 50 μM EDTA. The mercury chelates were detected spectrophotometrically at 475 nm. The detection limits were at the subnanogram level. The method is applicable to human urine, tap water and tomatoes.     

超声水浴-王水浸提-全自动测汞仪测定重度污染土壤中的总汞

为准确测定重度污染土壤中的总汞含量,本文建立了以超声水浴辅助王水浸提,使用全自动测汞仪测定的方法。 通过单因素实验考察了王水用量、超声时间和超声温度对土壤中总汞测定的影响,得到最佳前处理方法,最后应用建立的方法对重度污染土壤进行方法验证。确定了0.5 g土壤样品中加入5 mL的王水溶液,放入超声波清洗器中70℃水浴下超声提取70 min,使用超纯水定容至50mL的前处理方法,直接进样测定的实验方法。对该实验进行验证,结果表明,该方法汞低标准曲线汞含量在0～20ng范围内线性良好,相关系数R=0.9995;汞高标准曲线汞含量在20～150 ng范围内线性良好,相关系数R=0.9993;方法检出限为0.0055 mg/kg,方法定量下限为0.022 mg/kg;通过对土壤样品及土壤加标样品的测定,回收率为90.40～116.80%,表明该方法的准确度较高,RSD为1.89～3.34%（n=6）,表明该方法的精确度较高。超声水浴-王水浸提-全自动测汞仪法用于测定重度污染土壤中的总汞,前处理简单,自动化程度较高,可快速,高效的用于重度污染土壤总汞测定工作。     

Comparison of the Adsorbed Mercury Screening Method with Cold-Vapor Atomic Absorption Spectrophotometry for Determination of Mercury in Soil

ABSTRACT

A field screening method for the determination of elemental mercury in environmental soil samples involves the thermal desorption of the mercury from the sample onto gold and then the thermal desorption from the gold to a gold-film mercury vapor analyzer. This field screening method contains a large number of conditions that could be optimized for the various types of soils encountered. In this study, the conditions were optimized for the determination of mercury in silty clay materials, and the results were comparable to the cold-vapor atomic absorption spectrophotometric method of determination. This paper discusses the benefits and disadvantages of employing the field screening method and provides the sequence of conditions that must be optimized to employ this method of determination on other soil types.     

痕量汞分析的现状和展望

本文着重对汞的分离富集、形态分析、测定方法进行了评述,并讨论了汞分析方法的标准化问题。共引用文献82篇。     

Minimising the risk of some systematic errors by the use of the single vessel principle for cold vapour atomic absorption spectrometric determination of mercury in biological solids

The suitability of the single vessel principle (performing all steps of an analytical procedure in one vessel) for cold vapour atomic absorption spectrometric determination of mercury in biological solids was evaluated. The single vessel method gave a lower mean blank level with better precision, hence lower detection limits, as compared to the conventional method. The determination of total mercury in biological standard reference materials by the single vessel method also produced significantly higher mercury values and better precision than the conventional method. However, the mercury concentrations obtained in certified reference materials by the use of both methods were close to the mean certified values. Moreover, the use of the single vessel method is cost effective, rapid and environment friendly. The use of the single vessel technique is therefore recommended for accurate and reliable determination of mercury in biological solids.     

Direct determination of mercury in cosmetic samples by isotope dilution inductively coupled plasma mass spectrometry after dissolution with formic acid

A new method was proposed for the accurate determination of mercury in cosmetic samples based on isotopic dilution (ID)-photochemical vapor generation (PVG)-inductively coupled plasma mass spectrometry (ICP MS) measurement. Cosmetic samples were directly dissolved in formic acid solution and subsequently subjected to PVG for the reduction of mercury into vapor species following by ICP MS detection. Therefore, the risks of analyte contamination and loss were avoided. Highly enriched ²⁰¹Hg isotopic spike is added to cosmetics and the isotope ratios of ²⁰¹Hg/²⁰²Hg were measured for the quantitation of mercury. With ID calibration, the influences originating from sample matrixes for the determination of mercury in cosmetic samples have been efficiently eliminated. The effects of several experimental parameters, such as the concentration of the formic acid, and the flow rates of carrier gas and sample were investigated. The method provided good reproducibility and the detection limits were found to be 0.6 pg mL⁻¹. Finally, the developed method was successfully applied for the determination of mercury in six cosmetic samples and a spike test was performed to verify the accuracy of the method.     

氧弹分解-原子荧光法测定煤中汞的研究进展

介绍氧弹分解-原子荧光法测定煤中汞含量的研究进展。影响该方法主要因素为称样量、氧气浓度、吸收剂、还原剂、煤种以及灰分含量。分别综述了各个因素对该方法的影响,可为相关标准的制定提供参考。该方法能够简单、经济、快速地测定煤中汞的含量,但是目前学者们对于该方法的相关研究还存在分歧,需要进一步的研究验证;同时,还需要注意以下几个研究方向:吸收剂和还原剂的选择对汞回收率的影响;吸收剂在密闭氧弹中对汞的回收率及吸收时间的研究;氧弹废气中汞含量的测定;煤种和灰分含量对汞含量测定的影响。     

Sensitive determination of gaseous mercury in air by cold vapour atomic fluorescence spectrometry after amalgamation

A method was developed for the determination of mercury in air, using preconcentration by amalgamation on gold absorbers followed by measurement by atomic fluorescence spectrometry (AFS). The system has a detection limit of ca. 2.0 pg and the precision is in the range 5–10% (relative standard deviation). The accuracy was confirmed by comparison with cold vapour atomic absorption spectrometry. The method was applied to the determination of gaseous mercury in both indoor and outdoor air. As a result of the sensitivity small sample volumes can be analysed and only short sampling times are required. The method is thus suitable for continuous monitoring of mercury and for the fast and reliable determination of gaseous mercury in the atmosphere, even at background levels.     

Determination of total and methyl mercury in human permanent healthy teeth by electrothermal atomic absorption spectrometry after extraction in organic phase

A simple and sensitive method has been developed for determination of inorganic and methyl mercury in biological samples by ETAAS. For determination of methyl mercury; it was transferred to toluene phase by acid leaching extraction method. For total mercury after digestion of samples; it was extracted to toluene phase by means of the chelating agent diethyldithiocarbamate. Formation of complex between MeHg and diethyldithiocarbamate enhance the MeHg signal and increases the reproducibility. Furthermore, Pd-DDC was used as modifier for both mercury and methyl mercury determinations. The optimization performance was independently carried out by modifying the parameters such as temperature of mineralization, atomization and gas flow rate for methylmercury and inorganic mercury in ETAAS. The limits of detection were 0.15 and 0.12 μg g⁻¹ for methyl mercury and total mercury, respectively. The repeatability of the measurements of whole procedure were 15.8% for methyl mercury and 16.9% for total mercury determination. The accuracy of the method has been investigated by means of spiking different amounts of methylmercury and inorganic mercury to the samples. The recoveries were found within the range of 88-95% for methyl mercury and 85-92% for total mercury. For determination of total mercury, the method was validated by CVAAS. The obtained results by the present procedure were in good agreement with those of the CVAAS. The proposed method was applied for 30 human permanent healthy teeth (without filling) which significant positive correlations were found among number of amalgam filling and total mercury and MeHg.     

Highly sensitive spectrofluorometric determination of trace amounts of mercury with a new fluorescent reagent, 2-hydroxy-1-naphthaldehydene-8-aminoquinoline.

A new fluorescent reagent, 2-hydroxy-1-naphthaldehydene-8-aminoquinoline (HNAAQ), was synthesized. The fluorescent reaction of this reagent with mercury was also studied. Based on this chelation, a highly sensitive spectrofluorometric method was developed for the determination of trace amounts of mercury in a water-ethanol (5 + 1, v/v) medium at pH 8.0. Under these conditions, the Hg-HNAAQ complex has excitation and emission maxima at 406 and 445 nm, respectively. The linear range of the method is from 0 to 16 microg L(-1) and the detection limit is 0.056 microg L(-1) of mercury. The interference of other ions was studied. In order to enhance the selectivity in the determination of mercury by the present method, we also applied the separation of mercury by distillation. Thus, the selectivity of the method could be increased remarkably. The procedure can be easily performed, and affords good precision and accuracy. This method has been successfully applied to the determination of mercury in waste water and prawns.