原油中微量金属元素的测定及风化条件下元素的变化规律

建立了微波消解-电感耦舍等离子体质谱(ICP.MS)法同时测定原油及自然风化后原油中的V、Cr、Mn、Fe、Ni、zn、Mo、Ba等11种微量金属元素的方法.结果表明,11种微量金属元素的检出限为0.0056～0.8729μg/g,线性关系良好,相关系数r≥0.9995;相对标准偏差(RSD)<5.0%.经过30d风化...     

微波灰化-电感耦合等离子体原子发射光谱法测定原油中的金属元素

采用微波灰化技术消化原油样品,并使用电感耦合等离子体原子发射光谱法(ICP-AES)测定其中Na、Mg、Ca、Fe、V、Ni和Cu的含量。探讨了原油样品中金属元素测定的称样量和微波灰化程序,并优化了仪器工作参数和实验条件。样品经微波灰化处理后,用盐酸溶解残渣,方法对Na、Mg、Ca、Fe、V、Ni和Cu元素的检出限分别为0.07、0.01、0.01、0.01、0.02、0.04和0.03mg/kg,回收率在84.5%～96.6%之间,相对标准偏差在2.1%～6.9%范围。方法简便、可靠,可用于原油中Na、Mg、Ca、Fe、V、Ni和Cu 7种金属元素的检测。     

微波消解-高分辨电感耦合等离子体质谱(HR-ICP-MS)法测定原油中22种微量元素

准确测定原油中微量元素含量,对研究原油地球化学,揭示原油原产地信息,具有重要意义。本文采用HNO3微波消解原油样品,优化了样品质量、消解试剂、消解程序等微波消解条件,研究了原油中B、Mg、Al、P、Ti、Ca、V、Cr、Mn、Fe、Co、Ni、Cu、Zn、Ga、As、Sr、Mo、Cd、Sn、Ba、Pb共22种微量元素在低、中、高分辨率下的质谱干扰及校正方法,采用高分辨测定Ca,中分辨测定P、V、Cr、Mn、Fe、Ni、Cu、Cd、Co、Sr,低分辨率模式测定其余元素,建立微波消解-高分辨电感耦合等离子体质谱测定原油22种元素的方法。在优化的实验条件下,22种元素的线性相关系数均大于0.999,方法检出限为0.0002μg/g~0.07μg/g。选择原油多元素均质标准品（ConostanS-21）进行方法验证,B、Mg、Al、P、Ti、Ca、V、Cr、Mn、Fe、Ni、Cu、Zn、Mo、Cd、Sn、Ba、Pb元素测定结果的相对标准偏差为0.20%~2.80%,测定值与标准值基本一致;选择巴西原油、安哥拉原油、喀麦隆原油、尼日利亚原油进行Co、Ga、As、Sr元素加标回收试验,加标回收率为95.3%~104.3%,测定结果的相对标准偏差为0.2%~2.3%。选取巴西原油、安哥拉原油、喀麦隆原油、尼日利亚原油进行22种元素测定,分析了不同产地原油的元素含量差异。本方法能够应用于原油中多种微量元素的同时测定,灵敏度高,选择性好,检出限低,结果准确可靠,可为原油地球化学研究提供技术支持。     

原油中微量金属元素的测定及聚类分析

采用电感耦合等离子体质谱(ICP-MS)法测定了国内外18种原油样品中V、Ni、Cu等13种微量金属元素的含量.结果显示,方法的线性关系良好,相关系数r≥0.9995,相对标准偏差(RSD)＜5.0%,方法加标回收率为95.2%～116.2%.不同原油样品以Ni/V数值为聚类变量进行聚类分析,结果发现,国外与国内以及国...     

微波消解-微波等离子体炬原子发射光谱法测定原油和渣油中的铁、镍、铜和钠

采用微波消解技术消解原油和渣油,利用微波等离子体炬原子发射光谱法测定原油和渣油中的Fe、Ni、Cu、Na。考察了原油和渣油的最佳消解条件、各元素测定条件及共存元素对测定的影响。方法对Fe、Ni、Cu和Na元素的检出限分别为22、42、2．0和1．0μg/L;线性范围分别为0．1-100、0．15-50、0．01-5．0和0．006-2．0mg／L,应用该方法测定实际样品中Fe、Ni、Cu和Na的相对标准偏差分别为3．9％、3．6％、5．5％和3．4％。微波消解样品的测定结果与常规干法灰化法的测定结果相吻合。本方法省时、省酸、简便、快速,没有环境污染,具有一定的实际应用价值。     

甲苯中微量金属元素测定及特征分析

利用乙醇-水-稀硝酸乳化体系分散溶解甲苯样品,建立了电感耦合等离子体质谱(ICP-MS)同时测定甲苯中V、Cr、Mn、Fe、 Co、Ni、Cu、Zn、Ag、Cd及Pb等微量金属元素的新方法。采用有机进样系统,以Re多元素混标为内标元素,优化了仪器射频功率、载气流速、采样深度等仪器参数,以及乙醇-水比例和硝酸含量等样品前处理条件。结果表明,在最佳实验条件下,甲苯中多数微量金属元素的检出限均可达 ng/L级,各元素的线性关系良好(线性系数r=0.998 4~1.000);方法精密度较高,相对标准偏差(RSD)不大于8.0%;准确度和重现性较好,相对误差不高于10%。对不同厂家的甲苯样品进行分析,结果发现不同厂家样品的Zn、Mn与Co元素差异较大。该方法能够对不同厂家来源的甲苯进行区分,从而为实现海洋泄漏污染工业苯系物的鉴别提供一种新的辅助分析方法。     

微波消解样品-电感耦合等离子体原子发射光谱法测定中草药中微量铜锌钴锰

采用微波消解样品,电感耦合等离子体原子发射光谱法(ICP-AES)测定了野菊花、菊花、蒲公英、枇杷叶和蝉蜕5种中草药中铜、锌、钴、锰4种微量金属元素的含量.在最佳仪器条件下,对野菊花样品平行测定6次,各元素的加标回收率在96.0%～106.5%之间,相对标准偏差(n=6)均小于2.0%.铜、锌、钴、锰4元素的检出限(3S/N)依次为0.011,0.018,0.001 1,0.024 mg·L-1.     

电感耦合等离子体质谱法测定汽油中微量元素的研究

为建立电感耦合等离子体质谱(ICP-MS)测定汽油中V、Mn、Fe、Co、Ni、Cu、As、Pb等微量元素的分析方法,样品用HNO3微波消解后,试液直接用ICP-MS法测定,详细讨论了仪器工作参数、样品基体的干扰,以Sc、Re作为内标物质,补偿了基体效应,选择适当的待测元素同位素克服了质谱干扰,确定了实验的最佳测定条件。结果表明,8种微量金属元素的检出限在0.001~0.015μg/L之间;线性关系良好,线性相关系数r≥0.999 9;精密度良好,RSD2.78%;回收率在94.0%~106.0%之间;该法准确、快速、简便,应用于汽油中微量元素的测定,结果满意。     

微波消解/ICP-MS同时测定粮食、蔬菜中的11种重金属元素

建立了微波消解/电感耦合等离子体质谱法同时测定粮食和蔬菜中11种重金属元素(Cu、Mn、Cr、Pb、Cd、Ni、Sb、Hg、Co、Ag、As)的方法,优化了微波消解条件和仪器测定条件,采用HNO_3-HF-H_2O_2和HNO_3-H_2O_2两种混酸体系,将样品进行完全消解。结果显示,11种金属元素的线性系数不小于0.999 5,方法的检出限为0.001~10.00μg/L,测定的相对标准偏差(RSD,n=5)不大于5.0%。该方法具有快速、简便、灵敏度高、稳定性好、准确度高等优点。     

电感耦合等离子体质谱(ICP-MS)法测定土壤中6种重金属元素的不同前处理方法比较

样品前处理是测定土壤中金属元素的关键步骤,为保障测定结果能如实反应土壤环境状况,比较不同的前处理方法对土壤中6种金属元素的同时提取能力。论文基于电感耦合等离子体质谱技术,采用微波和石墨消解装置,探索消解过程中酸种类、加酸方式、消解装置、赶酸温度等因素对测定土壤标准品和实际样品结果的影响。实验结果表明,样品通过依次加入盐酸、硝酸、氢氟酸、高氯酸,并在160 ℃赶酸的石墨消解方式进行前处理能快速、准确地测定土壤中的Cu、Pb、Zn、Cd、Cr、Ni六种元素,其前处理时长约8.5 h,并且消解成本比微波消解更低。在优化条件下,土壤标准样品中6种金属元素的检测结果的绝对回收率为91.5%~108%,相对标准偏差为0.8%~ 5.4%,方法检出限为0.02 mg/kg ~2 mg/kg。表明方法的灵敏度高、准确度与精密度好,适用于批量土壤样品的分析。     

A combined method of sample preparation for the determination of the total element composition of oils

A comprehensive approach to the determination of the elemental composition of oils (including those with a viscosity of 5000 mm²/s) is proposed. It ensures the determination of the most elements present in oils using two versions of sample preparation, autoclave decomposition of oil samples and extraction preconcentration of elements from oil into an aqueous solution on rotating coiled columns (RCCs). The application of RCCs in the elemental analysis of oil ensures the preconcentration of a number of trace elements from oil (including rare-earth elements) and the determination of their concentrations at a level of ng/kg. The preconcentration factor of trace elements from oil using an RCC depends on the volume of oil sample pumped through a constant volume of the stationary phase (acid solution) retained in the column and on the speciation of elements in the oil.     

Trace element determination in crude oil and its fractions by inductively coupled plasma mass spectrometry using ultrasonic nebulization of toluene solutions

A method was developed for the determination of trace elements in crude oil by inductively coupled plasma mass spectrometry (ICP-MS) after sample dissolution in toluene and subsequent ultrasonic nebulization (USN). Carbon build-up at the interface and ion lenses was minimized by optimization of the argon to oxygen ratio in the plasma and by the desolvating action of the USN. The analyte addition technique, combined with internal standardization (¹¹⁵In), was the only calibration procedure capable to correct properly for signal suppression, especially observed in solutions with higher concentrations of asphaltenes. Analytical curves with good linearity (r²>0.99), and solution detection limits (LOD–3σ) of 0.1 μg l⁻¹ for V, Ni, Co, Y, Mo, Cd, Ba and La, and in the range of 0.1–1 μg l⁻¹ for Al, Ti, Fe, Zn, Sr, Ag, Sn and Pb were obtained. Method validation was performed by analyzing two certified reference materials. For National Institute for Standards and Technology (NIST) 1634c (V, Ni, Co), accuracy was approximately 10%, similar as observed for other 12 elements in NIST 1084a. Asphaltenes were separated from the oil bulk of crude oil samples from the Potiguar Basin (Brazil) using precipitation in heptane. The heptane-soluble fraction (maltenes) was separated by elution chromatography into three sub-fractions: (1) saturated and low molecular mass (MM) aromatics, (2) aromatics and low MM polar compounds, and (3) high MM polar compounds (resins). Trace elements were determined in these fractions after dissolution in toluene, by USN–ICP-MS. Mass balance calculations showed a significant increase of most elements (10–30 times) in the asphaltenic fraction, and in minor proportions in fraction 3, compared to the crude oil samples. Comparison with microwave-assisted acid decomposition showed good agreement, validating the proposed methodology and emphasizing its applicability for routine analysis of crude oil and other toluene soluble petroleum products.     

Counter-current chromatography for oil analysis: Retention features and kinetic effects

Application of counter-current chromatography (CCC) for oil analysis has been suggested for the first time. CCC looks very promising as a tool for pre-concentration and isolation of trace elements from oil. Features of stationary phase retention of two-phase liquid systems (oil or oil products–aqueous nitric acid solutions) in CCC have been investigated. The influence of physicochemical properties of crude oil and oil products used as a mobile phase on the volume of stationary phase (acidic aqueous solutions) retained in CCC was studied. Chromatographic behavior of several oil samples was studied. It has been shown that physicochemical properties of test oil influence its chromatographic behavior. Optimal values of density and viscosity (ρ < 0.85 g/cm³, n < 7 cSt) of crude oil and oil products that could be analyzed using CCC were estimated. The influence of the column rotational speed and flow rate of mobile phase on the stationary phase retention was also investigated. It is known that kinetic aspects (mass transfer of elements between phases) can play a very important role in selecting an optimal composition of stationary phase for the pre-concentration of elements from oil. The influence of nitric acid concentration in the stationary phase on mass transfer was studied. Kinetic characteristic for trace element recovery has been investigated for the optimization of pre-concentration conditions of trace elements from crude oil and oil products. The extraction recoveries of Zn, Mn, Fe, Ni, V, Cu, Cd, Pb and Ba by CCC in dynamic mode are in the range of 75–95% while they are lower than 35% under batch conditions.     

Direct μ-flow injection isotope dilution ICP-MS for the determination of heavy metals in oil samples

The determination of trace elements in oil samples and their products is of high interest as their presence significantly affects refinery processes and the environment by possible impact of their combustion products. In this context, inductively coupled plasma mass spectrometry (ICP-MS) plays an important role due to its outstanding analytical properties in the quantification of trace elements. In this work, we present the accurate and precise determination of selected heavy metals in oil samples by making use of the combination of μ-flow direct injection and isotope dilution ICP-MS (ICP-IDMS). Spike solutions of ⁶²Ni, ⁹⁷Mo, ¹¹⁷Sn and ²⁰⁶Pb were prepared in an organic solvent, mixed directly with the diluted oil samples and tested to be fit for purpose for the intended ID approach. The analysis of real samples revealed strong matrix effects affecting the ICP-MS sensitivity, but not the isotope ratio measurements, so that accurate results are obtained by ICP-IDMS. Typical relative standard deviations were about 15% for peak area and peak height measurements, whereas the isotope ratios were not significantly affected (RSD < 2%). The developed method was validated by the analysis of a metallo-organic multi-element standard (SCP-21, typically applied as a calibration standard) and the standard reference material SRM1084a (wear metals in lubricating oil). The obtained results were in excellent agreement with the certified values (recoveries between 98% and 102%), so the proposed methodology of combining μ-flow direct injection and ICP-IDMS can be regarded as a new tool for the matrix-independent, multi-element and reliable determination of trace elements in oil and related organic liquids.     

SPME/GC-MS鉴别地沟油新方法(Ⅲ)

该文通过气相色谱-质谱法研究调味品的化学成分,进而对地沟油进行鉴别,发现乙酸来源于醋、3-丁烯腈来源于腌菜酱汁、异硫氰酸烯丙酯来源于芥末、糠醛来源于酱油、茴香脑来源于八角茴香、姜烯来源于生姜和老姜。通过检测油脂样品中是否含有这些调味品的特征成分,即可鉴别是否餐厨废弃油。该文采用顶空固相微萃取(SPME)富集微量外源杂质成分,并研制专用的气相色谱柱,用气相色谱-质谱联用法(GC-MS)测定乙酸、3-丁烯腈、糠醛、异硫氰酸烯丙酯、茴香脑、姜烯6种成分,样品中若含有这些微量成分中的一种或多种,则判定为餐厨废弃油。     

Determination of cadmium, lead, and nickel by simultaneous multielement flame atomic absorption spectrometry in burned and unburned Venezuelan crude oil

This work describes the use of simultaneous multielement flame atomic absorption spectrometry for the determination of cadmium, lead, and nickel in burned and unburned Venezuelan crude oil (5 ml volumes) in controlled laboratory experiments. The simultaneous detection limits were 0.010 mug ml(-1) (Cd), 0.04 mug ml(-1) (Pb), and 0.40 mug ml(-1) (Ni) with precision's of these elements at concentrations of 10x above these detections limits, and in the crude oil, of 1-2%. Loss of elemental concentrations in the crude oil in a 3-5 ml volume when burned were 4% (Cd), 50% (Pb), and 22% (Ni). These results suggest that the form of the elements and the temperature attained in the burning crude oil effect the removal of the elements. The type of surface affected the volume of oil removed. Soil gave a 15% and a smooth surface almost 50% volume reduction.     

Modeling of cumulative release on long term leaching behaviour of selected oil sludge from crude oil terminal and petroleum refining plant

Management of oil sludge containing environmentally toxic elements is a major problem in crude oil processing industry. Oil sludge samples from the petroleum refinery plant in Melaka and crude oil terminal in Sarawak were analysed. The aim of present work is to study long term leaching behaviour of arsenic (As), cobalt (Co), chromium (Cr) and zinc (Zn) from oil sludge. Tank leaching test was carried out and the samples were analysed using inductively coupled plasma-mass spectrometry (ICP-MS). The results were studied using LeachXS software to plot the graphs of elements concentration in order to study the leaching behaviour of toxic elements in oil sludge. The long term leaching (100 years) modeling was calculated using equations referred to National Institute of Public Health and the Environment Bilthoven (RIVM) and the results were plotted for cumulative release in different areas of oil sludge. Tank leaching test of the oil sludge samples from petroleum refinery plant in Melaka showed concentrations of As, Co, Cr and Zn ranging from 0.205 to 1.102, 0.031–0.454, 0.016–0.086 and 0.409–8.238 mg/l, respectively while the concentrations of As, Co, Cr and Zn in oil sludge samples from crude oil terminal in Sarawak were in the range of 0.002–0.089, 0.001–0.033, 0.006–0.016 and 0.100–2.744 mg/l, respectively. On the other hand, results on cumulative release from the modeling of long term leaching (100 years) showed that As, Co, Cr and Zn concentrations were proportional to the quantity of oil sludge. In conclusion, during extrapolation of release of toxic elements using the data in the laboratory, several other factors were taken into account to suit environmental conditions such as soil moisture, the negative logarithm of the effective diffusion coefficient (pD_e) and temperature, while the long-term behaviour of As, Co, Cr and Zn was proportional to the quantity of oil sludge to be disposed off.     

Determination of <Emphasis Type="Italic">k</Emphasis><Subscript>0</Subscript>-values for some elements in neutron capture gamma-ray for prompt gamma activation analysis

Exploration and modification of data for k ₀-PGAA (prompt γ-ray activation analysis) values used as standards for k ₀ standardization are needed. An integrated system has been installed and calibrated in Hot Laboratories Center for PGAA, using ²⁵²Cf isotopic neutron source with neutron flux of 6.16E8 n/cm² s. The prompt k ₀-factors of about 12 elements were determined versus the 1951.1 keV γ-ray of the ³⁵Cl, as well as analyzing crude oil and oil product samples. The concentrations of the elements in crude oil H, B, Mg, Al, Na, Si, P, S, Cl, V and Cd were 1.18E5, 0.084, 5.48E2, 8.45E2 4.88E2, 1.62E2, 3.72E2, 8.2, 144.3, 393 and 209.2 ppm while in oil product samples were 1.32E5, 5.87, 4.56E2, 4.22E2, 7.16E3, 699, 157, 8.74, 492.3, 61 and 198.2 ppm. Validation of the k ₀-PGAA was applied in analyzing standard IAEA reference material (soil-7) which give good agreement with the literature data. The ²⁵²Cf neutron beam in radiation position was characterized by the cadmium-ratio method, and found that the cadmium ratio (f), was 160.     

Determination of nutrients and potentially toxic elements in Jatropha curcas seeds, oil and biodiesel using inductively coupled plasma mass spectrometry

Biodiesel is a renewable and biodegradable fuel that can be used in diesel engines as a replacement for fossil diesel. A suitable alternative is to produce it from Jatropha curcas, which has high quality oil concentration. Nevertheless, the presence of particular chemical elements above certain limits can affect the product quality, leading to vehicle engine problems and acting as air pollution source. The objective of this work is to develop a method for the simultaneous determination of B, Na, Mg, P, S, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Ba, and Pb in J. curcas seeds, oil and biodiesel using the inductively coupled plasma mass spectrometry (ICP-MS) technique. This material was evaluated because has been successfully employed in India for biodiesel production as well as in other places where there is an incentive to family farming, without affect the food chain. The oil was obtained from seeds via mechanical extraction and the biodiesel was achieved by oil transesterification. After optimization of the microwave digestion method for the different sample types, the samples were analyzed by ICP-MS. The certified reference material NIST SRM 1515 (apple leaves) and the recovery tests were carried out to ensure the accuracy of the proposed method, which made possible the quantification of several nutrients and potentially toxic elements in J. curcas seeds, oil and biodiesel, especially Na, K, Ca, Mg, P and S in biodiesel which are mandatory analyzed by Petroleum, Natural Gas and Biofuel National Agency (ANP). This work highlights the findings of the first study of potentially toxic and nutrient elements in the production chain steps seed–oil–biodiesel from J. curcas.     

辽河稠油减渣深度戊烷脱沥青的研究

以戊烷为溶剂,在脱沥青实验装置上对辽河稠油减渣进行梯级分离,得到轻脱油、重脱油和脱油沥青。在温度155℃~170℃、压力为4.0 MPa~7.0 MPa,考察了温度、压力变化对脱沥青油收率及性质的影响。用超临界萃取分馏的实验结果关联了脱沥青油残炭、N元素、Ni元素的脱除率。结果表明,压力升高、温度降低,脱沥青油收率增加,轻、重脱油的残炭值及S、N、Ni、V等元素含量升高,脱沥青油性质变差。在脱沥青油收率最高为74.23%时,Ca、Ni元素的脱除率分别为92.75%、74.50%;残炭的脱除率为62.13%;N、S元素的脱除率分别为40.17%、24.10%。超临界萃取馏分油的杂质脱除率与脱沥青油的杂质脱除率有较好的相关性。