Chemical analysis of resin fraction of Nigerian bitumen for organic and trace metal compositions

Studies of organics and trace metals of the resin fraction of Nigerian bitumen were carried out with an opinion to establish the environmental consequences of the fossil fuel and as well as characterize them. Bitumen samples were extracted from oil sands via Soxhlet extraction procedure using toluene as the extracting solvent. The bitumen samples were deasphaltened to obtain maltene by dissolving the samples in n-pentane (1:40). Column chromatography was used to fractionate the maltene into its components (saturates, aromatics, and resin) using silica gel as adsorbent and dissimilar solvents of varying polarity (n-hexane for saturates, toluene for aromatics, and methanol for resins). The organic compounds of the resin fraction were examined using Fourier Transform Infrared Spectrophometry (FTIR) and the elemental concentrations were determined using Inductively Coupled Plasma Optical Emission Spectrophotometry (ICP-OES). The infrared spectra of all the resin samples presented distinctive bands including expected polar functional groups which confirmed that the resin was cleanly eluted from the bitumen samples. The concentrations of the analyzed trace metals in the resin fraction were found to be high compared to other fractions and this was confirmed by their T-test values. Fe had the highest average concentration of 34.81 ± 14.37 mg/kg and a range of 19.35–47.48 mg/kg, while Mn had the least mean concentration of 0.94 ± 0.71 mg/kg and a range of 0.35–1.88 mg/kg. The result of cross-plot analysis revealed that resin fraction has strong and positive inter elemental correlation with the NSO and asphaltene fraction of the same bitumen samples. The overall results indicated that processing of the bitumen and/or its resin may cause catalyst poisoning and fouling, corrosion of equipment and pipelines, and particulate emissions into the environment and therefore adequate demetalisation of the fossil fuel must be done before processing.     

Evaluation of Trace Metals and Physical Properties of Nigerian Crude Oil Saturate Fraction

Analyses of trace elements and physical properties of the saturate fraction of Nigerian crude oil were done in order to establish the characteristics that may aid the developmental processes of the natural resources. Crude oil samples were collected from three different oil fields in Niger-Delta area of Nigeria. The saturate fractions were eluted by column chromatography using n-hexane. The saturate fractions were investigated for functional groups using Fourier transform infrared spectrometry (FT–IR); the elemental concentrations were determined using Atomic absorption spectrometry, while the physical properties (flash point, ash content, refractive index, and color) were determined using standard analytical methods. The results revealed that the infrared spectra of the saturate fraction of the Nigerian crude oil showed mainly the presence of C-H(CH₃) and C-H(CH₂) functional groups, indicating high purity of the samples. The concentrations of the analyzed elements (Mn, Cu, Co, Zn, Fe, V, Cr, and Ni) in the saturate fraction were generally low compared to other fractions of Nigerian crude oil. This study revealed that Co has the highest mean concentration of 1.81 ± 0.36 mg/L, while Mn has the lowest mean concentration of 0.04 ± 0.02 mg/L. The t test values for the comparison of the elemental concentrations of Nigerian crude oil /saturate fraction and crude oil asphaltene/saturate fraction showed significant difference (except Mn) with respect to Nigerian crude oil /saturate fraction. The cluster analysis for the elements showed two groups, which are fairly well correlated indicating similar source and similar chemical affinity. The cross-plot analysis of the Nigerian crude oil and its saturate using elemental concentrations as the variables showed a strong positive inter element correlation since (R² = 0.71), establishing a relationship between the Nigerian crude oil and the saturate fraction. The color of the saturate fraction ranged from off-white to colorless. The results of analysis provide useful information on its conversion mechanism and environmental implications of the development of the fossil fuel deposit.     

The Reclamation of Fine Lubricating Oil From Flat Lubricating Oil Using a Combination of Activated Animal Charcoal and Amberlite Resin

This study aims at recovering quality rerefined (fine) and metal-free base oil from used lubricating oil. Samples of used lubricating oils were subjected to sedimentation, extraction using methylethylketone and elution using n-hexane on activated animal charcoal, amberlite resin, and ratio 1:1 mixture of activated animal charcoal/amberlite resin separately to produce fine oils. The fine oils obtained, unused, and used (control) lubricating oils of the same brand (Mobil Super XHP SAE 20W-50) were subjected to atomic absorption spectroscopy (Buck Model 205) to determining the levels of 10 wear metals (Fe, Cu, Mn, Cd, Zn, Ni, Cr, Pb, Sb, and Se). Iron has the highest mean concentration (638.56 μg/g), while Mn has the least average level (8.72 μg/g) in the used lubricating oils. Comparison of the elemental concentrations of the rerefined oil with the used and unused (control) lubricating oils indicated that the concentrations of the analyzed wear metals were high in the used and unused (control) lubricating oils. This was corroborated by their t test values. All the three adsorbents used are confirmed to be effective in metal removal from the used lubricating oils, but the mixture (1:1) of the activated animal charcoal/amberlite resin proved to be the best option since the elusion is moderately fast, apart from been an effective metal removal adsorbent, it removed unwanted obnoxious color effectively.     

Spectroscopic Characterization of Asphaltene Fraction of Nigerian Bitumen

This research article offers data on the spectroscopic elucidation of the asphaltene fraction of Nigerian bitumen in order to establish its features that might aid the developmental processes of the fossil fuel. Bitumen was extracted from the oil sands obtained from six locations where there were oil sand out-crops in Southwestern Nigeria using toluene via Soxhlet extraction and then deasphalted using n-pentane. The organic components of the precipitated asphaltenes were investigated using Fourier transform infrared spectrometry, while the elemental contents were determined using Inductively coupled plasma atomic emission spectroscopy and carbon/nitrogen analyzer. The results revealed that the average content (29.15 wt%) of Nigerian bitumen asphaltenes was less than that of Athabasca (40.10 wt%) but slightly higher than that of Cold Lake bitumen (24.40 wt%). The IR spectra of the asphaltenes indicated the presence of various organics and heteroatoms corroborating that asphaltenes composed of high molecular weight polycyclic constituents comprising of nitrogen, sulfur, and oxygen heteroatoms. The results indicated that the values of Cr, Cu, Fe, Mn, Ni, S, V, and Zn were comparatively higher in the asphaltenes than the parent bitumen due to the presence of comparatively high levels of porphyrins in the asphaltenes than the bitumen, while the concentrations of all the elements were higher in the Nigerian bitumen asphaltene than Nigerian crude oil asphaltene (except S and C). Cross plot analysis result between the asphaltenes and bitumen using their elemental mean concentrations as variables indicates that significant and positive correlation (R² = 0.975) exists between them, indicating very strong interelement and geochemical relationships between them. The elements showed close clustering, indicating similar sources because the elements were known to associate with petroleum hydrocarbon formation. Also, apart from N, S, and C, other elements are transition metals with similar chemical affinity.     

Processing Lunpola Crude Oil

Abstract

The characteristics of crude oil from Lunpola of Xizang were studied, and the properties of different fractions were analyzed. The results indicated that this crude has great density and viscosity, solidifying points are high, and water cut is especially high. It is rich in wax and resin, but less in asphaltene, which belongs to low-sulfur intermediate-based crude oil. Looking at these characteristics, water cut oil should be more than 90°C, while dehydrated crude should be more than 100°C when it is stored, freighted, gathered, and transported; otherwise, these things will be more difficult. A reasonable processing scheme was put forward for producing diesel oil, paraffin, lube stock, and road asphalt, because it does not have a gasoline fraction but has a high diesel oil fraction and cetane number.     

Geochemical evidences of trace metal anomalies for finding hydrocarbon microseepage in the petroliferous regions of the Tatipaka and Pasarlapudi areas of Krishna Godavari Basin, India

The long-term seepage of hydrocarbons, either as macroseepage or microseepage, can set up near-surface oxidation reduction zones that favor the development of a diverse array of chemical and mineralogical changes. The bacterial oxidation of light hydrocarbons can directly or indirectly bring about significant changes in the values of pH and Eh of the surrounding environment, thereby also changing the stability fields of the different mineral species present in that environment. The paper reports the role of hydrocarbon microseepage in surface alterations of trace metal concentrations. In this study trace metal alterations were mapped that appear to be associated with hydrocarbon microseepages in the oil/ gas fields. A total of 50 soil samples were collected near oil and gas fields of the Tatipaka and Pasarlapudi areas of the Krishna Godavari Basin, Andhra Pradesh. The soil samples were collected from a depth of 2-2.5 m. The paper reports the chemical alterations associated with trace metals in soils that are related to hydrocarbon microseepages above some of the major oil and gas fields of this petroliferous region. Trace metals, such as scandium (Sc), vanadium (V), chromium (Cr), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), barium (Ba) and strontium (Sr), in soil samples were analyzed using inductively coupled plasmamass spectrometry (ICP-MS). The concentrations of Sc (8 to 40 mg/kg), V (197 to 489 mg/kg), Cr (106 to 287 mg/kg), Co (31 to 52 mg/kg), Ni (65 to 110 mg/kg), Cu (88 to 131 mg/kg), Zn (88 to 471 mg/kg), Ba (263 to 3,091 mg/kg) and Sr (119 to 218 mg/kg) were obtained. It was observed that the concentrations of trace elements were tremendously increased when they were compared with their normal concentrations in soils. The analysis of adsorbed soil gas showed the presence of high concentrations of ΣC 2+ (C 2 H 6 , C 3 H 8 and n-C 4 H 10 ) ranging from 7 to 222 μg/kg respectively. Integrated studies of trace elements over adsorbed light gaseous hydrocarbons (ΣC 2+ ) anomalies showed good correlation with the existing oil and gas wells. The carbon isotopic composition of δ 13 C 1 of the samples ranges between -36.6‰ to -22.7‰ (Pee Dee Belemnite) values indicate thermogenic origin, which presents convincing evidence that the adsorbed soil gases collected from these sediments are of catagenetic origin. The increase in the concentrations of trace metals near oil/gas producing areas, suggests a soil chemical change to a reducing environment, presumably due to the influence of hydrocarbon microseepage, which could be applied with other geoscientific data to identify areas of future hydrocarbon exploration in frontier areas.     

Effect of acid number of crude oil on oil recovery of smart water coupled with silica nanoparticles

Spontaneous imbibition (SI) is one of the most important mechanisms in reservoir engineering. In order to activate of this mechanism completely in carbonate reservoirs, wettability of these oil wet rocks should be altered to water-wet. Multi-step spontaneous imbibition tests were designed and conducted in this study. Results indicated that mixture of smart water and nano silica could increase oil recovery up to 5 percent. Effect of acid number of crude oil on oil recovery of this mixture was investigated by using three samples of crude oil during SI tests: A (0.38 mg KOH/g), B (0.25 mg KOH/g) and C (0.18 mg KOH/g). Maximum oil recovery of SI tests was recorded for oil sample C which had lowest acid number. Ion analysis of imbibing fluids indicated sharp reductions in concentration of sulfate ion in each step of SI tests which confirmed occurrence of ion exchange mechanism in the rock surface of core samples.     

Evaluation of interfacial tension between ASP solution and crude oil from B oil field

The interfacial tension (IFT) between alkali-surfactant-polymer (ASP) solution and crude oil is an important parameter for evaluating the feasibility of the ASP flooding for an oil field. The IFT between six series of ASP solution and crude oil from B oil field were measured at 65°C. Each series of ASP solution was composed of NaOH or Na₂CO₃, one of the three kinds of surfactants (S1, S2, and S3), and polymer FT60. The concentration of FT60 and surfactant were 1500 and 2000 mg/L, respectively. The research results show that the IFT between ASP solution and crude oil is ultra-low in the NaOH-FT60-S2 series and NaOH-FT60-S3 series and the best concentration of NaOH is 4000 mg/L and 8000 mg/L, respectively. NaOH-FT60-S2 series is more suitable for B oil field. The IFT between ASP solution and crude oil is ultra-low in the Na₂CO₃-FT60-S2 series and the best concentration of Na₂CO₃ is 4000 mg/L.     

Geochemical investigation of trace elements in crude oils from two different depobelts in the Niger Delta basin,Nigeria

The concentrations of trace elements in crude oil samples from the Northern and Central swamps depobelts in the Niger Delta basin were investigated using Flame Atomic Absorption Spectrometer. The origin, source facies, and depositional environment of organic matter that produced the oils were determined based on the trace elements concentrations. The concentrations of the trace elements (Cr, Cu, Fe, Mn, Ni and V) ranged from 0.04 to 5.71 ppm. Iron is the most abundant element in the samples while Cr has the least concentration. The results from trace metal geochemistry showed that the Niger Delta oils were derived predominantly from terrestrial organic matter deposited in the oxic depositional environment. The concentrations and ratios of nickel and vanadium grouped the oils into two distinct families reflecting the depobelt the oils belong. This observation indicates that the source rocks in the two depobelts were formed from organic matter of different source facies.     

A Comprehensive Evaluation of High Viscous Crude Oil from Shuguang No. 1 Zone of Liaohe Oil Field

Abstract

The high viscous crude oil from Shuguang No. 1 zone of Liaohe oil field has the characteristics of high density (ρ ₂₀ = 0.9977 g cm^?3), great viscosity (ν ₁₀₀ = 1223.9 mm² s^?1) and high pour point (48°C), which are similar to those of the residue distillation of general crude oils. It contains no gasoline distillation and the diesel oil fraction yield is just 7.19%. It is often used as fuels after emulsification. But this oil is so vicious that it cannot be atomized uniformly and burned fully. In order to make full use of it, this kind of high viscous crude oil has been evaluated comprehensively and the properties of its various distillations are analyzed respectively. The results indicate that this crude oil contains less wax, but more resins and asphaltene, which belongs to low-sulfur naphthene-base crude oils and it is the suitable material to produce high-quality paving asphalt. Based on its characteristics, the optimum processing scheme is put forward and the high-quality paving asphalt is produced by using the distillation higher than 350°C.     

The action mechanism of wax inhibitors (WI) on pour point and viscosity of mixed waxy oil

Several methods had been used to minimize the problems caused by wax deposition in crude oil pipelines during the production and transportation of waxy crude oil; among them, the continuous addition of wax inhibitor (Abbreviation for WI) is considered as the most efficient one. This study uses two kinds of polymeric compounds as wax inhibitors with different solvents on the pour point and viscosity of mixed waxy oils evaluated. These four wax inhibitors defined as WI-1, WI-2, WI-3, WI-4, respectively. Five types of mixed waxy oil have the same wax content but different resin contents. Meanwhile, different resin contents affect the pour point and viscosity of mixed oils. Under different processing temperature, the viscosity of mixed oil measured when the temperature changes among 20 to 60°С. In this work, the results were that the effect of WI-1 and WI-3 relied on the resin content, processing temperature and dosing concentration. For mixed waxy oils, the pour point reductions contacted with dosing concentration and the resin content. The wax inhibitor shows good efficiency when the resin content was between 1.01 and 4.03 wt %. When the WI-1 added, the pour point of mixed oil-1 reduced 30°С at most and viscosity of mixed waxy oil greatly reduced. In sum, toluene as solvent shows better performance of wax inhibitors.     

Process optimization of silica encapsulation technique as a unique remediation technology for the treatment of crude oil contaminated soil

The effect of hydrocarbon pollution on soil quality is globally challenging. Addressing the menace of pollution on soil necessitates research into the development of viable remediation technique that is fast, effective, efficient and environmentally friendly; with cutting edge advantages over conventional remediation techniques. The technique was designed using a formulated silica encapsulating product and applied on soil contaminated by simulation with 10% crude oil. Soil was characterized for its physicochemical properties using standard methods, while its TPH content determined by molecular spectroscopy. Properties such as conductivity, pH and phosphorus levels were severely impacted by the hydrocarbon effect. Silica encapsulating product was formulated from sodium silicate and sodium dodecyl sulphate using proper optimization procedures. The encapsulating product (sodium silicate and SDS) were used in a ratio of 1:2. Optimum concentrations of 60,000 ppm sodium silicate solution, 120,000 ppm SDS, applied at optimum pH and temperature of 5 and 25 °C respectively were established from the process optimization of the experimental technique. The technique shows rapid response towards TPH removal, as 86.79% TPH reduction is achieved after seven days of treatment. The encapsulation process follows pseudo first order kinetics. Significant reduction in metals; Ni (0.61–0.036 mg/kg), V (0.82–0.11 mg/kg) and Cd (0.05–0.016 mg/kg) shows the efficacy of the technique, thereby providing a dual alternative for the remediation of hydrocarbons and heavy metals. The technique seems to be effective in restoring some lost soil properties as seen in pH, conductivity and total nitrogen after treatment. The environmental friendliness, cost effectiveness and merits associated with this technique gives it a unique advantage over other conventional methods; as such presents promising alternative route for remediation experts in addressing the challenges associated with hydrocarbon and metals pollution on soil. Silica encapsulation technique is therefore suitable for outright applications in real field challenges.     

Production of biodiesel from dairy wastewater sludge: A laboratory and pilot scale study

This study investigates the production of biodiesel from activated sludge of milk processing plant as a low cost feedstock. The method involves lipid extraction, refining and optimization of biodiesel from activated sludge under laboratory conditions. These results were scaled up to a pilot plant was analyzed. In the laboratory study, the sludge yielded 18.81?wt% of crude lipid. It is degummed and dewaxed to get refined oil that is used for the production of biodiesel. The optimal reaction parameters were 0.8?wt% catalyst; a temperature of 55?°C; 6:1 methanol to oil molar ratio for 40?min. The process is scaled up to a prototype demonstration plant with a batch size of 10?kg. The dried sludge yielded 16.2?±?1.3?wt% and 13.64?±?0.8?wt% of crude lipid and biodiesel respectively. Biodiesel made in pilot plant is compared with ASTM standards.     

Process Simulation and Modeling of Fluidized Catalytic Cracker Performance in Crude Refinery

The simulation of fluidized catalytic cracking (FCC) process was performed using Aspen HYSYS. The effect of crude flow rate on naphtha flow, coke yield, and catalyst to oil ratio in FCC were simulated. The interaction effects of riser height, inlet crude flow rate and operating temperature on naphtha mass flow, catalyst to oil ratio, and coke yield were studied by Box-Behnken design. The maximum yield of naphtha (100000 kg/h) was obtained for FCC operating temperature within 520–600°C and riser height greater than 30 m. The catalyst to oil ratio of above 12 was obtained for operating temperature beyond 590°C for the entire riser height variation of 10 to 60 m in FCC. The increase in riser height resulted in increase production of naphtha, but beyond 60 m of riser height secondary cracking occurs resulting in reduction in yield of naphtha.     

Geochemistry,generation and maturation of the hydrocarbons at Wadi Al-Rayan oil field,Western Desert of Egypt

`The present work aims to study the organic chemistry, the generation and maturation of the hydrocarbons encountered at Abu Roash Formation, Wadi El Rayan oil field. The analysis of source rocks indicates the presence of two organic facies. The first is characterized by high total organic carbon of 0.93–3.39%, strongly oil-prone (Type II), and good potential for oil generation (pyrolysis S2 yields 4.54–23.26 mg HC/g rock and HI 488–705 mg HC/g TOC). The second attains good range of organic carbon from 0.90% to 1.57%, which is a mixed oil and gas (Type II–Type III) of fair hydrocarbon generation (pyrolysis S2 yield of 1.98–5.33 mg HC/g). The kerogen type consists of unstructured lipids and some terrestrial material. Plot of Pr/n-C17 versus Ph/n-C18 indicates that the crude oil was derived from mixed source rock, while the maturity profile assigns oil windows (0.6 R_o%) matching topmost of Abu Roash G Member.     

AN EXPERIMENTAL APPROACH OF ELEMENTAL SULFUR DEPOSITION IN CARBONATE OIL RESERVOIRS

The existence of sulfur compounds in crude oils creates many problems of sulfur deposition in the vicinity of the wellbore hole, in well completion and/or production equipment, and in producing reservoir rocks. The major objectives of this experimental study are to investigate the influences of oil flow rate, initial sulfur concentration of crude oil, and reservoir rock permeability on elemental sulfur plugging in carbonate oil reservoirs. To achieve these objectives, actual crude oils were de-asphaltened to eliminate the effect of asphaltene deposition. Ten dynamic flow experiments were conducted using two actual crude oils of 0.78 and 1.67% sulfur concentrations. Viscosity of crude oils of different sulfur concentrations was measured under different conditions of temperature. The crude oils were flooded through actual carbonate cores of different permeability in the range of 2.34-28.16 millidarcy and under different flow rates of 0.5, 1.0, 1.5, and 2.0 cc/min. In-situ sulfur deposited was measured using Scanning Electron Microscopy (SEM) to provide the amount of sulfur deposited along the core samples. The results indicated that crude oil of higher sulfur concentration has higher viscosity than that of one of lower concentration. The deposition of elemental sulfur does not take place at the low rate of 0.50 cc/min, starts at 1.0 cc/min and increases as the flow rate increases up to 1.50 and 2.00 cc/min, respectively. In addition, the higher sulfur concentration of the crude oil increases the deposition of sulfur in carbonate oil reservoirs. The results also showed that permeability of carbonate reservoir rocks has a severe effect on sulfur deposition since carbonate rocks of higher permeability do not experience the problem of elemental sulfur deposition while the problem is more severe for lower permeability rocks. In addition, the depositional rate is accelerated rapidly as the rock permeability decreases. The obtained results of this study have important interest in identification of the most important factors affecting the elemental sulfur precipitation in heterogeneous carbonate oil reservoirs and robust implications in the development of reservoir simulation models.     

The Structural Characterization of Saturate,Aromatic, Resin,and Asphaltene Fractions of Batiraman Crude Oil

Abstract

The structural characterization of fractions of Batiraman crude oil, which is the heavy crude oil from a field in the southeastern part of Turkey, was investigated. Batiraman crude oil and its saturate, aromatic, resin, and asphaltene (SARA) fractions were seperated. Treatment of crude oil with n-heptane provided the separation of asphaltene. Maltene was collected by evaporating the n-heptane from the filtrate. Then, maltene was separeted into saturates, aromatics, and resins by SARA technique. Maltene was separated into saturate, aromatic, and resin fractions using column chromatography. SARA fractions were quantified on a weight percent basis. Fractions of Batiraman crude oil were characterized by elemental analysis, proton nuclear magnetic resonance (¹H NMR) analysis, electrospray ionization mass spectrometry (ESI-MS), and Fourier transform infrared (FTIR) spectroscopy techniques.     

Effect of natural-style processing on the oxidative and hydrolytic degradation of the lipid fraction of table olives

The aim of this work was to determine the effect of natural-style processing, by using three different cultivars, on the oxidative and hydrolytic degradation of the lipid fraction of table olives. Samplings were made at harvest and after 4 and 8 months of processing. The Italian table olive cultivars Bella di Cerignola, Termite di Bitetto, and Peranzana, diffused in the Apulia region, were considered. During processing, the total phenols content of the lipid fraction decreased from 381–417 mg/kg oil to 106–125 mg/kg oil, depending on the cultivar. The level of primary oxidation at the end of processing was relatively low, as compared to high quality lipids such as extra virgin olive oil: peroxide value and oxidized triacylglycerols accounted for 11.7–13.1 meq O₂/kg oil and 3.3–7.1 g/kg respectively, depending on the cultivar. A very modest secondary oxidation occurred, as shown by final amounts of triacylglycerol oligopolymers ranging from 0.6 to 0.9 g/kg. On the contrary, a relevant hydrolytic degradation was observed, with free fatty acids accounting for 2.04–2.25 g/100 g oleic acid and diacylglycerols in the range 45.4–48.0 g/kg, at the end of processing. The polar compounds, mainly represented by diacylglycerols, reached values in the ranges 41.1–55.9 g/kg after 4 months and 58.0–62.0 g/kg after 8 months.     

Crude oil UV spectroscopy and light scattering characterization

Crude oil is a complex mixture of hydrocarbons representing several classes of compounds. Some of these constituents significantly affect refinery processes and analysis procedures. Ultraviolet-visible (UV-vis) spectroscopy has received wide acceptance because of its broad scope, given that many active species in the spectrum of UV, and many more that with proper treatment, are able to form visible species in that spectrum. In this study two crude oils from different sources were analyzed without dilution C1-RC, in the coastal region and C2-RM of the maritime region of the Gulf of Mexico. Stages for obtaining calibration curves depending on the change in concentration of crude, starting from crude standard solutions and evaluating the repeatability of the method and the dispersion, were established. The results show three signals: (a) 230 nm corresponding to benzene compounds, (b) 260 nm to naphthenic compounds, and (c) 410 nm Soret band corresponding to the metal porphyrins. These species are found in asphaltenes, signals were evaluated individually for separate calibration curves, at concentrations between 10 and 90 mg L^?1. The model equation of each curve based on the absorbance and concentration determination coefficient values for each compound are reported. It was possible to establish that the method developed is suitable for oil solutions at low concentrations.     

基于ICP-MS/MS分析微量金属元素的原油产地溯源

建立电感耦合等离子体串联质谱(ICP-MS/MS)法测定原油中微量金属元素的分析方法,结合聚类分析(CA)建立判别模型,进行原油产地溯源研究。原油样品经微波消解处理后,采用ICP-MS/MS测定其中18种微量金属元素Mg、Al、Ti、V、Cr、Mn、Fe、Co、Ni、Cu、Zn、Rb、Sr、Mo、Ag、Cd、Ba、Pb的质量分数。在MS/MS模式下的碰撞反应池(CRC)中,应用O2或NH3/He为反应气可消除多原子离子对轻质量元素的干扰,采用国际标准物质燃油(NIST SRM 1634c)验证了分析方法准确可靠性,并利用多种微量金属元素质量分数的比值进行聚类分析。方法的检出限为0.43～59.2 ng/L,相对标准偏差(RSD)不大于4.82%;CA将18种原油聚为4大类,可实现原油产地的初步判别。通过微量金属元素的ICP-MS/MS分析,并结合CA能够对原油进行有效的产地溯源和判别。