Multielemental Analysis of Human Serum by Dynamic Reaction Cell–Inductively Coupled Plasma Mass Spectrometry

The selection of the most suitable dilution methods for determination of trace elements in human serum using inductively coupled plasma mass spectrometry is reported. The trace elements were Al, V, Cr, Fe, Mn, Co, Cu, Zn, As, Cd, Sn, Tl, and Pb. The performance of various dilution methods was assessed by precision, linearity, detection limits, quantification limits, fortified recoveries, and the analysis of reference materials. The results demonstrate that diluted solution containing only nitric acid is most suitable for As, Cr, Mn, and Co in serum. Dilute solutions containing nitric acid and Triton X-100 were most appropriate for Cu, Zn, Cd, and Tl. The optimum conditions for Al, V, Mn, Fe, Cr, Co, Sn, and Pb used tetra-n-butylammonium hydroxide, Triton X-100, and ethylenediamine tetraacetic acid.     

Accurate determination of ultra-trace levels of Ti in blood serum using ICP-MS/MS

Ti is frequently used in implants and prostheses and it has been shown before that the presence of these in the human body can lead to elevated Ti concentrations in body fluids such as serum and urine. As identification of the exact mechanisms responsible for this increase in Ti concentrations, and the risks associated with it, are not fully understood, it is important to have sound analytical methods that enable straightforward quantification of Ti levels in body fluids (for both implanted and non-implanted individuals). Until now, only double-focusing sector field ICP-mass spectrometry (SF-ICP-MS) offered limits of detection that are good enough to deal with the very low basal levels of Ti in human serum. This work reports on the development of a novel method for the accurate and precise determination of trace levels of Ti in human serum samples, based on the use of ICP-MS/MS. O₂ and NH₃/He have been compared as reaction gases. While the use of O₂ did not enable to overcome all spectral interferences, it has been shown that conversion of Ti⁺ ions into Ti(NH₃)₆⁺ cluster ions by using NH₃/He as a reaction gas in an ICP-QQQ-MS system, operated in MS/MS mode, provided interference-free conditions and sufficiently low limits of detection, down to 3 ng L⁻¹ (instrumental detection limit obtained for the most abundant Ti isotope). The accuracy of the method proposed was evaluated by analysis of a Seronorm Trace Elements Serum L-1 reference material and by comparing the results obtained with those achieved by means of SF-ICP-MS. As a proof-of-concept, the newly developed method was successfully applied to the determination of Ti in serum samples obtained from individuals with and without Ti-based implants. All results were found to be in good agreement with those obtained by means of SF-ICP-MS. The typical basal Ti level in human serum was found to be <1 μg L⁻¹, while values in the range of 2–6 μg L⁻¹ were observed for implanted patients.     

De novo synthesis of glycosaminoglycans by equine multipotent mesenchymal stromal cells in vitro – Studied by stable isotopic labeling and matrix-assisted laser desorption ionization mass spectrometry

Glycosaminoglycans (GAGs) play an important role in extracellular matrix (ECM) homeostasis and are crucial for maintaining the specific biomechanical and functional properties of musculoskeletal tissues. Aiming at regenerating these tissues, multipotent mesenchymal stromal cells (MSCs) are frequently used, their targeted differentiation and ECM synthesis being a part of their complex mechanism of action. To achieve a better understanding of these processes and to improve the targeted use of the cells for the development of regenerative therapies, reliable quantification of GAGs synthesized by MSCs represents an important step. The aim of this study was to develop a novel technique to specifically assess the de novo synthesis of GAGs, particularly chondroitin sulfate (CS), by MSCs.

Adipose tissue-derived equine MSCs were cultured in vitro for 2, 7, 14, and partially 28 d. Harvested cell populations were enzymatically digested with chondroitinase ABC from Proteus vulgaris and afterwards subjected to CS analysis by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).

The herein chosen detection method of MALDI-TOF MS combined with enzymatic digestion represents a reliable technique to monitor the culture time-dependent GAG biosynthesis of MSCs cultured in vitro. Furthermore, the addition of ¹³C-labeled glucose as cell culture medium supplement is a useful approach to obtain information regarding cellular GAG and in particular CS synthesis.     

直接稀释/电感耦合等离子体质谱法测定人血清中微量元素

建立了一种高灵敏度、高通量和低样品消耗的人血清中微量元素的质谱检测方法。针对血清样品基质复杂的特点,采用正四丁基氢氧化铵、曲拉通和EDTA的混合液直接稀释样品,使用内标元素校正和碰撞反应池技术来抑制基质效应和多原子离子的干扰,通过仪器调谐和碰撞反应池工作参数的优化,成功检测了人体血清中Al、Cu、Fe、Zn、Ga、As、Cd、Hg、Tl、Pb10种微量元素的含量,各元素的加标回收率为87.2%~111.2%。方法用于人血清标准物质(ClinChek-Control,LevelⅠandLevelⅡ)测试,测定值与标准值相符。采用此方法对127名成年健康人血清样品进行检测,基于检测结果给出了不同年龄、性别组的均值和测量值范围。     

微流动注射进样-加热雾室-等离子体质谱测定血清中的铂

开发了一种基于雾化室加热的微流动注射进样系统,并用于血清中Pt的测定。该进样系统由微量毛细管雾化器、加热微型雾化室、八通道十六孔多功能旋转阀、蠕动泵和注射泵组成。研究了雾化室尺寸、加热温度和采样环体积对信号强度的影响。当雾化室内径为9mm、加热段长度为6cm,雾化室温度90℃,采样环体积为5μL时,195Pt的信号强度提高了2.31倍,同时信号精密度从5.1%降至2.2%,并得到峰形良好的信号峰。该进样系统的试样消耗小、灵敏度和检出限均优于常规进样系统。10次测定10μg/L的Pt标准溶液和血清样品溶液,峰高的RSD分别为2.9%和3.3%。该进样系统测得10个血清中的Pt含量与常规进样系统的测试结果无显著差异,在样品量稀少的情况下具有良好的应用价值。     

同位素稀释热电离质谱法测定人血清中痕量铜和锌

采用热电离同位素稀释质谱法(ID-TIMS)准确测定了欧盟标准物质与测量研究院(EC-JRC-IRMM)组织的国际测量评估计划IMEP-17人血清样品中的痕量铜和锌。由于锌和铜都是易受污染的元素,本工作建立了仅用少量硝酸消解的低流程本底和适于热电离质谱测量的生物基体血清中痕量铜和锌的样品前处理方法;采用适当比例的硅胶和磷酸作为电离增强剂,在热电离质谱(TIMS)测量时获得了较高强度且稳定的铜和锌离子束;血清中痕量铜和锌的测量结果可直接溯源到国际单位mole。2种人血清样品中铜和锌测量结果的不确定度(k=2)分别为0.94%、0.83%和0.49%,测量值被EC-JRC-IRMM采用作为该样品的标准值。     

动态反应池电感耦合等离子体质谱(DRC-ICP-MS)法测定血清中钛含量

钛合金常被用作医用植入物,这些植入物的存在可能会导致血液中钛含量的升高。血清中大量存在的钙、磷和硫等元素会导致同量异位素和多原子离子质谱干扰,严重影响电感耦合等离子质谱仪(ICP-MS)测定人血清中钛含量的准确性。本文建立了应用动态反应池电感耦合等离子体质谱(DRC-ICP-MS)技术测定血清钛的方法。通过筛选确定氨气为反应气,优化气体流量及剔除参数(RPq)对钛含量测定的影响。结果显示,选用NH3作为反应气体,利用离子分子反应特性,将钛离子转换为钛和氨的络合物,可以成功地消除干扰,钛的回收率保持在80%至120%之间。根据检出限和定量限的优选,选择出最优的48Ti(NH)(NH3)4+(m/z 131)质量数进行分析,检出限和定量限分别为0.012μg/L和0.037μg/L。通过标准物质检验和加标回收率两种手段来验证方法的准确度,分别对两个血清标准物质进行6次测定,RSD分别为2.9%和1.3%,加标回收率为94.0%～113.6%。实验结果表明,通过与标准模式的比较,利用氨气的质量转移模式可以能有效地去除干扰,灵敏度和检出限均较好。该方法可用于准确测定血清中的痕量钛。     

液相色谱-串联质谱法测定人血浆中卡托普利的浓度

建立了测定人血浆中卡托普利的LC/MS/MS法。取血浆0.2 mL,用对溴苯甲酰甲基溴进行衍生化,经甲醇沉淀蛋白后,以甲醇-10 mmol/L乙酸铵-甲酸(80/20/0.4,V/V)为流动相,用Zorbax SB-C18柱分离,通过配有电喷雾离子化源的四极杆-线性离子阱质谱仪,以多反应监测(MRM)方式进行检测。用于定量分析的离子反应分别为m/z416→m/z216(卡托普利衍生物)和m/z28→m/z193(安定)。卡托普利的线性范围为2.5~1000μg/L,最低定量限为2.5μg/L,样品分析时间为2.0 m in。该法精密、准确,在灵敏度和分析速度上优于以往文献报道,适用于游离型卡托普利血药浓度的监测和药动学研究。     

Capillary electrophoresis inductively coupled plasma mass spectrometry

Chemical speciation (extraction of elemental information and identification of molecular environment for an analyte in a complex sample) has been a long sought after goal for analytical chemists. Recently, because of successful developments in more sensitive element-specific detectors and gentle separation schemes, which preserve the true chemical information in a real sample, routine speciation experiments are becoming a common occurrence in the scientific literature. For many reasons, the combination of capillary electrophoresis (for separation of different chemical species) with inductively coupled plasma mass spectrometry (for element and isotope specific detection) has emerged as the method of choice for these analyses. In this article the basic principles of capillary electrophoresis inductively coupled plasma mass spectrometry are discussed. Design consideration for instrument interface, anticipated difficulties with speciation experiments and applications for specific matrices and analytes are also presented in this article.     

Liquid chromatographic tandem mass spectrometric determination of trandolapril in human plasma

A liquid chromatographic tandem mass spectrometric method for the determination of trandolapril in human plasma has been developed and fully validated. The article describes, in detail, the bioanalytical procedure and summarizes the validation results obtained. The samples were extracted using HLB Oasis solid-phase extraction cartridges. The chromatographic separation was performed on X-Terra C8 MS column (150 mm × 4.6 mm i.d., 5 μm particle size) using a mobile phase consisting of acetic acid 20 mM and triethylamine 4.3 mM/acetonitrile (40:60 (v/v)), pumped isocratically at 0.35 ml/min.

The analytes were detected using a micromass quattro micro triple quadrupole mass spectrometer with positive electrospray ionization in multiple reaction-monitoring (MRM) mode. Tandem mass spectrometric detection enabled the quantitation of trandolapril down to 2.0 ng/ml. Calibration graphs were linear (r better than 0.996, n = 9) in the concentration ranges 2.0–750 ng/ml and the intra- and inter-day R.S.D. values were less than 3.83 and 3.86% for trandolapril.     

Plasma Desorption Ionization Mass Spectra of Unconjugated Human Steroids

Abstract

Steroids, including cortisone, Cortisol, aldosterone, cortol, preg-nanediol, androsterone and 4-androsten-3, 17-dione can be ionized directly, without derivative formation, by plasma desorption ionization to give characteristic mass spectra. The ion products, with isobutane as the reagent gas, indicate the nature of the functional groups and the molecular formula; the spectra are similar to those obtained by chemical ionization methods.     

气相色谱-电感耦合等离子体质谱

从接口设计、色谱和质谱技术的应用和实际应用等方面对气相色谱－电感耦合等离子体质谱的进展进行了介绍。     

电感耦合等离子体发射光谱与质谱分析技术与应用研究进展

电感耦合等离子体发射光谱(ICP-OES)和电感耦合等离子体质谱(ICP-MS)分析技术都是以 ICP 为激发源或离子源的无机元素分析技术,在仪器操作、标准物质的配制及进样方式上均有相似之处,成为无机元素测定的得力工具,其溶液进样方式具有朔源性而被各个领域的标准分析方法所采纳,ICP-OES/MS分析方法在标准化方面得到了较快发展。本文介绍了近年来(ICP-OES仪器的现状、分析功能的发展及其应用上的进展;对ICP-MS分析技术的发展、四极杆电感耦合等离子体质谱分析(ICP-QMS)仪器的进展以及在纳米颗粒分析、生物化学、形态分析、地质年代学等领域中应用的进展进行评述。     

HPLC-ICP-MS and HPLC-ES-MS/MS characterization of synthetic seleno-arsenic compounds

Various toxicological and metabolic interactions have been reported to exist between arsenic and selenium. In the present study, synthetic seleno-arsenic compounds, potentially suitable for probing metabolic interactions between these two elements, were prepared and tentatively characterized by using high-performance liquid chromatography (HPLC)–electrospray tandem mass spectrometry and HPLC–inductively coupled plasma mass spectrometry. In analogy to the recently identified thio-arsenic species, which can be prepared from their corresponding oxo-arsenic species via reaction with H₂S, the seleno-arsenic compounds were also derived from oxo-arsenic compounds via reaction with H₂Se. Figure H₂Se bubbled into solutions containing oxo‐arsenosugars converts them into their seleno‐arsenosugar analogues.     

介质阻挡放电离子源质谱分析

敞开式离子化质谱可对表面样品进行直接快速分析而受到关注,成为质谱分析的热点研究方向.介质阻挡放电离子源是一种基于等离子体放电机理的敞开式离子源,近年来得到了较快的发展.本文着重介绍该离子源的基本原理、性能特征以及应用进展,并对其发展趋势进行了展望.     

Single-step microwave digestion with HNO(3) alone for determination of trace elements in coal by ICP spectrometry

A microwave digestion method with HNO₃ alone was conducted at a temperature as high as 250 °C for determination of 19 trace elements (Li, Be, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Cd, Cs, Ba, Hg, and Pb) in coal jointly by inductively coupled plasma optical emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), and flow injection ICP-MS (FI-ICP-MS). The validity of determination was assessed by using three standard coals, SRM 1632c, BCR 180, and SARM 19. It was found that the high-temperature digestion led to an extensive decomposition of the organic matrix and clay in coal, and no dissolved and solid carbon remained in the final solution after evaporation. Good recoveries were observed for all trace elements in three coals, with the exception of V, Rb, and Cs in high-ash SARM 19. Additionally, FI-ICP-MS combined with the present digestion without evaporation pretreatment was proved to be a rapid and efficient approach for determination of ultra-trace elements such as Se, Cd, and Hg in coal.     

Elemental,Isotopic, and Pesticide Analysis of Wild and Cultivated Berries

ABSTRACT

The focus of this study was to investigate differences in isotopic, elemental, and trace pesticide concentrations of wild and cultivated berries from Transylvania. To emphasize differences based on geographical origin, stable isotopic ratios of ²H/¹H, ¹⁸O/¹⁶O, and ¹³C/¹²C were determined by isotopic ratio mass spectrometry. Elemental fingerprinting of berries was performed by inductively coupled plasma mass spectrometry. The determination of trace pesticides in berries was performed by gas chromatography–mass spectrometry. Differences between wild and cultivated berries were evaluated using multivariate statistical analysis. The results suggest that multielemental, isotopic, and trace pesticide fingerprinting is feasible for sample differentiation.