Experimental designs in the optimisation of ultrasonic bath-acid-leaching procedures for the determination of trace elements in human hair samples by atomic absorption spectrometry

Experimental designs were used for the optimisation of acid-leaching procedures assisted by ultrasonic energy for the extraction of Ca, Cu, Fe, Mg, Mn and Zn from human hair samples. A Plackett-Burman 2(7) x 3/32 design for seven factors ([HNO3], [HCl], [H2O2], acid/oxidant solution volume, exposure time to ultrasounds, temperature of the ultrasonic bath and hair particle size) was used in order to choose the variables affecting the acid-leaching process. The variables [HNO3], [HCl] and temperature of the ultrasonic bath were found to be the most important parameters for the acid-leaching procedure, and these variables were optimised by a response surface design (central composite design 2(3) + star) which involved 16 experiments. Optimum values in the 3.7-4.2 M range were found for [HNO3], while optimum values between 3.0 and 3.5 M were found for [HCl]. The optimum temperature of the ultrasonic bath was between 80 and 90 degrees C. An acid digestion induced by microwave energy (details given) was used to obtain the total metal concentration and also for comparative purposes. Ca, Cu, Fe, Mg and Zn were measured by flame atomic absorption spectrometry (FAAS) using a conventional air/acetylene flame, while Mn was determined by electrothermal atomic absorption spectrometry (ETAAS) under optimised conditions. Two different reference materials, IAEA-085 International Atomic Energy Agency, Monaco) and NIES No. 13 (National Institute for Environmental Studies, Japan), with certified metal contents for some of the elements investigated, were used in order to verify the accuracy of the methods.     

A study of illicit cocaine seizure classification by pattern recognition techniques applied to metal data

Fifteen metallic species, silver (Ag), aluminum (Al), calcium (Ca), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), sodium (Na), nickel (Ni), lead (Pb), strontium (Sr) and zinc (Zn), were determined in 46 cocaine samples confiscated by the Spanish police in Galicia (northwest Spain). Classification of these cocaine samples according to their geographic origin (Colombia and Venezuela) was achieved by the application of pattern recognition techniques to the metallic content data. Cocaine samples, around 0.5 g, were directly dissolved in 2 mL of 35.0% (v/v) HNO3, diluted to 10 mL with ultrapure water. The metals were quantified by means of electrothermal atomic absorption spectrometry (Ag, Al, Cd, Cr, Cu, Mn, Ni, Pb and Sr), flame atomic absorption spectrometry (Ca, Fe, Mg and Zn), and flame atomic emission spectrometry (K and Na). Results show that two geographic origins can be established through the presence of trace and major elements.     

微波消解ICP/AES标准加入法测定尿液中金属毒物

目的建立微波消解ICP/AES标准加入法测定尿液中As、Ba、Pb、Cd、Cr、Zn、Sb金属毒物。方法取1.0mL尿样,加入3mL浓硝酸和0.5mL双氧水,进行微波消解。冷却后,用2%的硝酸定容至10.0mL。采用标准加入ICP/AES法进行定量分析,并优选实验条件及考察方法可靠性。结果尿液中As、Ba、Pb、Cd、Cr、Zn、Sb回收率在98.6%～104%之间;检出限在2.0～5.1ng/mL之间;线性范围Zn为5.0～200.0μg/mL,其余元素为0.5～20.0μg/mL。采用本文方法测定与国家标准物质人发和牛肝数据测定值基本一致。结论该方法回收率高、检测限低、能多元素同时测定,可以用于尿液中金属元素的检测。     

Levels of trace and major elements in illicit heroin

Ten elements, aluminum (Al), barium (Ba), calcium (Ca), cadmium (Cd), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), lead (Pb), and zinc (Zn) were analyzed in 44 illicit heroin samples from Southeast Anatolia, Turkey. Illicit heroin samples were dissolved in nitric acid using microwave oven and were quantified by electrothermal atomic absorption spectrometry (Cd and Pb) and inductively coupled plasma-atomic emission spectrometry (Al, Ba, Ca, Cu, Fe, Mg, Mn, and Zn). The most abundant element was calcium, 4050 to 14,200 microg/g, which could be ascribed to the use of lime in the manufacturing process and/or as diluting agent. Iron (180 to 1470 microg/g), aluminum (42 to 2280 microg/g), and zinc (160 to 210 microg/g) were found at moderately high levels, possibly because of the use of metal pots in the acetic anhydride cooking process and also for storage. Cadmium and lead concentrations were at the lowest measured levels. The amounts of magnesium, manganese, barium, and copper were in the range of 100 to 800 micro/g, 3 to 17 microg/g, 4 to 30 microg/g, and 2 to 46 microg/g, respectively.     

电感耦合等离子体质谱法检测电流损伤皮肤中金属元素

目的探讨应用电感耦合等离子体质谱(inductively coupled plasma mass spectrometry,ICP-MS)技术检测电流损伤皮肤中金属元素的可行性,建立检测电流损伤皮肤中金属元素的方法。方法用黄铜、紫铜、铝、铁电极材料以220V交流电电击家兔后肢,ICP-MS对电流损伤皮肤中金属元素进行检测。结果与对照组比较:黄铜电击组皮肤中的Cr、Ni、Cu、Zn、Pb含量升高(P0.05),紫铜电击组皮肤中的Cr、Cu、Pb含量升高(P0.05),铝电击组皮肤中的Al、Cr、Mn、Co、Ni、Cu、Pb含量升高(P0.05),铁电击组皮肤中的Cr、Mn、Fe、Ni含量升高(P0.05)。不同电极材料电击后皮肤中元素种类及含量也存在明显差异。结论ICP-MS可作为检测电流损伤皮肤中金属元素的有效方法,且可应用于触电材料的推断。     

Identify the injury implements by SEM/EDX and ICP-AES

The forensic investigator is frequently confronted with the discrimination and deduction of injury implements, which is one of the most important physical testimonies in courts. The usual method used in actual cases is from points of morphology. In the forensic discrimination of injury implements, such as metal implements, the analysis and comparison of elements are expected to provide excellent results, and simultaneous multi-elemental analysis is required to analyze various kinds of elements. This study was designed to establish discrimination and deduction of metal injury implements by scanning electron microscope/energy disperse X-ray microanalyzer (SEM/EDX) and inductively coupled plasma atomic emission spectrometry (ICP-AES). Examined metal particles in five wounds made on the skin of domestic pigs, respectively, using Cu-Zn or Cr-Ni coated and carbon steel kitchen implements by EDX. For carbon steel kitchen implements, analyzed five samples from the back and blade separately in the contents and varieties of elements by ICP-AES. In the wounds by the coated implements, the special particles only containing Cu, Zn or Cr, Ni were found. In the wounds by carbon steel kitchen implements, the particles containing Fe, Cr, Si or Fe, Mn, Si were found. The differences of contents of elements between the back and blade was no significant except No. 5 for carbon steel kitchen implements, and the significant differences of elements exited in Cr, Mn, Si, Cu, Mo among the stainless kitchen knives, Mn, Si among the other kitchen implements and for the blade of No. 5 knife, relative standard deviations (R.S.D.s) were significantly different in Mn, Si, Mo, Ti, S, P, Ni. Using EDX to examine the particles in wounds can deduce the categories of metal injury implements, and we can still deduce the different implements in the same category by ICP-AES.     

A chemical and physicochemical study of an Egyptian mummy 'Iset Iri Hetes' from the Ptolemaic period III-I B.C

Chemical and physicochemical examinations of the fragments of an Egyptian mummy dated between the 3rd and 1st century B.C. were performed. The chemical examinations indicated the presence of resin in the skull and in the fragments of bandages wrapped around the mummy. An analysis of the infrared spectra of the fragments indicated a type of resin originating from the Copal group. Physicochemical investigations showed that main chemical elements such as Ca, Mg, Na, K, P and trace chemical elements such as Fe, Zn, Cu, and Pb occurred in bone fragments in proportions typical for people living today. In tooth fragments, values were similar to normal except for K, P, and Zn, which were lower, and Pb, which was absent. In the fingernails, most elements were found in much higher concentrations except for Cu and Pb, which were lower. The results of the study in terms of their implications on mummification are discussed.     

应用SEM/EDX和ICP-AES检测元素成份判定致伤工具

目的应用扫描电镜/能谱联合分析仪(Scanning electron microscopy & Energy dispersive X-ray apparatus SEM/EDX)和电感耦合原子发射等离子光谱(inductively coupled plasma-atom emission spectrometer ICP-AES)对金属致伤工具本身及所致创口残留物元素成分分析,探讨两者在推断认定此类工具的应用条件及价值.方法镀层和普通铁质工具在乳猪皮肤各致创5例,SEM/EDX对创口内遗留金属颗粒元素检测;用标准样品检测实验方法的精确度;普通铁质工具于刀背、刀刃处各取5个样本,ICP-AES测定元素成分与含量.结果镀锌工具所致创口中存在单一含有锌的金属颗粒,镀黄铜工具则同时含有锌和铜,未发现其它元素;不锈钢或普通铁质菜刀创口中,发现同时含有铁、铬、硅或铁、锰、硅的颗粒;除5号菜刀外同一把铁质菜刀在刀刃、刀背处元素含量无明显差别;ICP-AES分析表明不锈钢菜刀之间在铬、锰、硅、铜、钼和5号刀背部以及其他铁质菜刀在锰、硅元素含量差别具有显著意义,5号刀刃部锰、硅、钼、钛、磷、硫、镍元素RSD明显升高.结论SEM/EDX可以通过创口的检测对金属致伤工具进行种类的推断认定,ICP-AES则可在同种类致伤工具中进行相对同一的判定有应用价值.     

应用SME/EDX和ICP-AES检测元素成份判定致伤工具

目的应用扫描电镜／能谱联合分析仪(Scanning electron microscopy&Energy dispersive X-ray apparatus SEM／EDX)和电感耦合原子发射等离子光谱(inductively coupled plasma-atom emission spectrometer ICP-AES)对金属致伤工具本身及所致创口残留物元素成分分析，探讨两者在推断认定此类工具的应用条件及价值。方法镀层和普通铁质工具在乳猪皮肤各致创5例，SEM／EDX对创口内遗留金属颗粒元素检测；用标准样品检测实验方法的精确度；普通铁质工具于刀背、刀刃处各取5个样本，ICP-AES测定元素成分与含量。结果镀锌工具所致创口中存在单一含有锌的金属颗粒，镀黄铜工具则同时含有锌和铜，未发现其它元素；不锈钢或普通铁质菜刀创口中，发现同时含有铁、铬、硅或铁、锰、硅的颗粒；除5号菜刀外同一把铁质菜刀在刀刃、刀背处元素含量无明显差别；ICP-AES分析表明不锈钢菜刀之间在铬、锰、硅、铜、钼和5号刀背部以及其他铁质菜刀在锰、硅元素含量差别具有显著意义，5号刀刃部锰、硅、钼、钛、磷、硫、镍元素RSD明显升高。结论SEM／EDX可以通过创口的检测对金属致伤工具进行种类的推断认定，ICP-AES则可在同种类致伤工具中进行相对同一的判定有应用价值。     

微波消解ICP-MS法测定人发中的汞

目的建立人发中汞的电感耦合等离子体质谱分析方法。方法采用微波消解法处理样品,以铟（115In）作内标,用电感耦合等离子体质谱分析人发中的汞含量。结果方法检出限为0.0032μg/g,准确度通过测定人发标准物质GBW07601、GBW09101b进行验证,检测结果与标准参考值相符。结论该方法快捷、高效,灵敏度、准确度高,适用于人发中汞含量的检测。     

尿液中铊的微波消解ICP／AES标准加入测定法

目的建立尿液的微波消解和金属毒物铊的ICP／AES标准加入分析方法。方法取1．0mL尿样于聚四氟乙烯消解管中,加入3mL浓硝酸和0．5mL双氧水,进行微波消解。冷却后,用2％的硝酸定容至10．0mL。根据标准加入法进行ICP／AES定量分析。结果回收率为101．5％,检出限为2．6ng／mL,线性范围为0．05ug／mL～2．0ug／mL。结论该方法操作简便,回收率高,检出限低,可多元素同时测定,结果可靠。     

Quantitative analysis of glasses used within Australia

An initial 134 glasses have been collected from eleven classifications of glass used within Australia. These include both local and imported glasses. Quantitative elemental analyses of the glasses have been determined using a scanning electron microscope equipped with an energy dispersive X-ray spectrometer. The current program provides for an elemental analysis for Na, Mg, Al, Si, P, S or Pb, Cl, K, Ca, Ba or Ti, V, Cr, Fe, Mn and Zn expressed as oxides, and has a sensitivity down to approximately 0.1%. The data for the six most commonly occurring elements, namely, Na, Mg, Al, Si, K and Ca, together with the refractive index are presented for each class of glass in terms of their mean value and standard deviation from the mean, and also in histogram form.     

A fast ultrasound-assisted extraction procedure for trace elements determination in hair samples by ICP-MS for forensic analysis

An ultrasound-assisted extraction method is proposed for the determination of trace elements in hair samples by inductively coupled plasma-mass spectrometry (ICP-MS) for forensic investigation. Prior to analysis, 25 mg of hair samples were accurately weighed into (15 mL) conical tubes. Then, 2 mL of 20% HNO₃ is added to the samples, sonicated at 2 min (50 W, 100% amplitude), and then further diluted to 10 mL with Milli-Q water. Resulted diluted slurries are centrifuged and the analytes are directly determined in the supernatant. Calibrations against aqueous solutions were carried out with rhodium as internal standard. The method was successfully applied for the extraction of Al, As, Ba, Be, Cd, Co, Cr, Cu, Mn, Pb, Tl, U, V and Zn with a method detection limit (3 s, n = 20) of 0.1, 0.4, 0.2, 0.09, 0.08, 0.04, 0.1, 2.9, 1.0, 0.9, 0.04, 0.05, 0.1 and 4.2 ng/g, respectively. Method accuracy is traceable to Certified Reference Materials (CRMs) 85 and 86 human hair from the International Atomic Energy Agency (IAEA). Additional validation data are provided based on the analysis of hair samples from the trace elements intercomparison program operated by the Institut National de Sante’ Publique du Quebec, Canada. The proposed method is very simple and can be applied for forensic purposes with the elimination of sample digestion step prior to analysis. Then, a considerable improvement in the sample throughput is archived with the use of the proposed method.     

Extent of Groundwater Contamination Due to Leachate Migration Adjacent to Unlined Landfill Site of Delhi

The leachate and groundwater samples were collected from the 2 km radius of Ghazipur landfill site. The high levels of EC, TDS, Chloride, Nitrate, Sodium, Potassium, BOD, and COD were observed in the leachate and groundwater samples. In leachate, metal concentrations were found in the order as – Fe > Zn > Cu > Pb > Ni > Cr > Cd. In groundwater, Zn, Ni, and Cu ranged as 0–0.386 mg/l, 0–0.013 mg/l, and 0–0.027 mg/l, respectively whereas Cd, Cr, and Pb were found in trace amount. The study clearly indicates that the percolation of leachate from the landfill site results in the contamination of groundwater of the surrounding area.     

Particle characteristics of trace high explosives: RDX and PETN

The sizes of explosives particles in fingerprint residues produced from C-4 and Semtex-1A were investigated with respect to a fragmentation model. Particles produced by crushing crystals of RDX and PETN were sized by using scanning electron microscopy, combined with image analysis, and polarized light microscopy was used for imaging and identifying explosive particles in fingerprint residues. Crystals of RDX and PETN fragment in a manner that concentrates mass in the largest particles of the population, which is common for a fragmentation process. Based on the fingerprints studied, the particle size to target for improving mass detection in fingerprint residues by ion mobility spectrometry (IMS) is > or = 10 microm in diameter. Although particles smaller than 10 microm in diameter have a higher frequency, they constitute < 20% of the total mass. Efforts to improve collection efficiency of explosives particles for detection by IMS, or other techniques, must take into consideration that the mass may be concentrated in a relatively few particles that may not be homogeneously distributed over the fingerprint area. These results are based on plastic-bonded explosives such as C-4 that contain relatively large crystals of explosive, where fragmentation is the main process leading to the presence of particles in the fingerprint residues.     

微波消解ICP-MS法测定人头发中24种元素的含量

目的建立人头发中24种无机元素的电感耦合等离子体质谱（inductively coupled plasma-mass spec-trometry,ICP-MS）分析方法。方法采用微波消解法处理样品,以铟（115In）作内标,用ICP-MS分析人头发中的24种元素含量。同时检测56例健康志愿者和10例海洛因滥用者头发中24种元素含量。结果 24种元素的方法检出限范围为0.0003~10.14μg/g,标准物质的测得值与标准值基本相符。海洛因滥用者经戒毒治疗后头发中镁、镓、钡含量下降。结论该方法灵敏度、准确度高,适用于头发中24种元素的测定。     

Detection of nitro-organic and peroxide explosives in latent fingermarks by DART- and SALDI-TOF-mass spectrometry

The ability of two mass spectrometric methods, surface-assisted laser desorption/ionization-time of flight-mass spectrometry (SALDI-TOF-MS) and direct analysis in real time (DART-MS), to detect the presence of seven common explosives (six nitro-organic- and one peroxide-type) in spiked latent fingermarks has been examined. It was found that each explosive could be detected with nanogram sensitivity for marks resulting from direct finger contact with a glass probe by DART-MS or onto stainless steel target plates using SALDI-TOF-MS for marks pre-dusted with one type of commercial black magnetic powder. These explosives also could be detected in latent marks lifted from six common surfaces (paper, plastic bag, metal drinks can, wood laminate, adhesive tape and white ceramic tile) whereas no explosive could be detected in equivalent pre-dusted marks on the surface of a commercial lifting tape by the DART-MS method due to high background interference from the tape material. The presence of TNT and Tetryl could be detected in pre-dusted latent fingermarks on a commercial lifting tape for up to 29 days sealed and stored under ambient conditions.     

电热板消解电感耦合等离子体质谱法测定人发中33种无机元素的含量

目的建立头发中33种无机元素的电热板消解电感耦合等离子体质谱（inductivelycoupledplas—ma—IllasssDectrometry,ICP—MS）测定方法。方法以锂（6Li）、锗（^72Ge）、钇（^89Y）、铟（^115In）、铽（^159yb）作内标,硝酸和过氧化氢作为消解酸体系．采用电热板消解对头发进行前处理,ICP—MS法分析人发中33种无机元素的含量。结果电热板消解ICP—MS法的检出限为0．0001μg／g（Th）-10．9μg／g（Ca）,定量限为O．0005μg／g（Th）～25μg／g（Ca）,加标回收率为86％～113％,日内及日间精密度≤9.2％,与微波消解法检测结果相比,差异无统计学意义。结论电热板消解ICP—MS法高效、准确度高,适用于对头发中33种无机元素的分析。     

微波消解ICP-MS法检测生物检材中汞元素

目的 建立生物检材中汞的电感耦合等离子体质谱分析方法.方法 采用微波消解法处理样品,以铟(115In)作内标,用电感耦合等离子体质谱仪对血液、尿液和头发中的汞含量进行分析.选择金与汞形成金汞齐,对金消除汞记忆效应的能力进行考察.结果 方法检出限为0.01μg/L,准确度为97.0%～107.1%.检测中添加金质量浓度在...     

The identification of the emulsifier component of emulsion explosives by liquid chromatography-mass spectrometry

ABSTRACT: The widespread availability of emulsion explosives for commercial blasting has inevitably lead to their diversion for criminal misuse. Present techniques for the characterization of emulsion explosives and their residues is generally based on the detection and identification of the oxidizer and the hydrocarbon components. Use of these components is problematic for residue identification because ammonium nitrate, waxes, and oils are relatively common in the urban environment and even their co-detection does not exclude them being sourced from materials other than explosives. The detection of the emulsifier component offers increased evidential value as certain emulsifiers used in explosive formulations are manufactured for that specific use, or have limited environmental distribution. In the current study liquid chromatography-mass spectrometry (LC-MS) was utilized for the characterization of two emulsifiers in common use; ethanolamine adducts of polyisobutylene succinic anhydride and sorbitol mono-oleate (SMO). The LC-MS technique enabled the detection of both emulsifiers in preblast samples; however, only SMO was detected in postblast residues. The analysis of the hydrocarbon component by gas chromatography-mass spectrometry was achieved in the same procedure.