固相微萃取在生物体液分析中的研究进展

固相微萃取是一种无溶剂样品预处理技术。固相微萃取以其无需使用溶剂、样品用量少、有一定的富集作用等特点而受到广大分析工作者的关注。本文着重综述了该方法的装置、原理、影响因素及其应用，尤其是在使用气相色谱—质谱联用、高效液相色谱—质谱联用技术分析生物体液中的应用。     

人血浆中奥美沙坦的HPLC-MS/MS测定

建立了HPLC—MS／MS法测定人血浆中的奥美沙坦，以替米沙坦为内标。采用C18色谱柱，流动相为甲醇-水（64：36，含0．2％乙酸）。质谱条件为电喷雾离子源，多离子反应监测，定量分析离子为m／z447→429（奥美沙坦）和m／z515→497（替米沙坦）。血浆样品采用固相萃取处理，线性范围为4～1000ng／ml，检测限为1ng／ml。     

基于HS-SPME-GC-MS快速分析毛橘红和光橘红挥发性成分

目的:建立可快速分析毛橘红和光橘红挥发性成分的方法。方法:采用固相微萃取-气相色谱-质谱联用技术对两种化橘红的挥发性成分进行分析与鉴定。结果:毛橘红鉴定出55种挥发性成分,占总挥发性成分的90.15%。从光橘红鉴定出52种挥发性成分,占总挥发性成分的87.15%。毛橘红有10种挥发性物质独有的,光橘红有7种挥发性物质独有的。结论:固相微萃取-气相色谱-质谱联用技术为两种化橘红的挥发性成分快速鉴别提供技术手段和科学依据。     

大鼠血浆中积雪甙浓度的HPLC/MS/MS测定

建立了HPLC／MS／MS测定大鼠血浆中的积雪甙。以柴胡皂甙D为内标，采用XTerra C18柱，流动相为O．1％乙酸和含O．1％乙酸的乙腈，梯度洗脱。质谱条件为电喷雾离子源，检测方式为多反应检测，定量分析离子为m／z981．5→493（积雪甙）和803→331（柴胡皂甙D），血浆样品采用固相萃取处理。检测限为0．5ng／ml。     

血、尿中安眠酮及其代谢物的测定

通过一例安眠酮中毒病人血、尿中安眠酮及其代谢物的测定,描述了用紫外光谱(uv)、气相色谱(GC)和气相色谱质谱(GC/MS)法测定安眠酮及其代谢物的系统分析方法。样品的提取净化采用液一液萃取和固相萃取两种方法,都得到了很好的结果。紫外光谱用于测定血、尿中安眠酮和其代谢物的总量;气相色谱用于测定血、尿中安眠酮原药的含量;气相色谱质谱则用于鉴定血、尿中的安眠酮及其代谢物。除安眠酮外,血、尿中共检出10种安眠酮代谢物,其中包括两种乙酰化代谢物。此法还为临床救治提供指导。     

固相微萃取-气相色谱-质谱联用分析云木香挥发油成分

目的:利用固相微萃取-气相色谱-质谱联用技术分析云木香挥发油的化学成分,为云木香的挥发油成分分析提供新方法。方法:固相微萃取法提取挥发油,气相色谱-质谱联用技术对挥发油成分进行分离鉴定,并采用面积归一化法确定各成分的相对质量分数。结果:样品在110℃下平衡30 min,吸附15 min,100μm PDMS纤维头能有效地吸附云木香挥发油成分。GC-MS共鉴定出52个成分,其中相对质量分数较高的有7,10,13-十六碳三烯醛(40.06%)、去氢木香烃内酯(17.60%)、α-芹子烯(4.05%)、α-姜黄烯(4.22%)。结论:云木香挥发油具有丰富的化学成分,固相微萃取-气相色谱-质谱联用能全面快速地获得其组成信息,可应用于云木香挥发油成分的快速分析。     

色谱联用技术在药物分析中的应用

简述色谱联用技术如色谱-质谱联用、色谱-固相微萃取联用和色谱-色谱联用等技术的基本特点以及在药物及其代谢产物研究、天然药物化学成分分析及生物大分子分析等方面的应用.     

大鼠尿中人参皂苷Rd及其代谢物的LC-MS研究

目的探讨人参皂苷Rd在大鼠体内的代谢产物及转化途径。方法选择SD大鼠6只，单剂量口服和静脉给予人参皂苷Rd，分段收集给药前和给药后0～24 h尿样，将尿样分时段合并后采用旋转薄膜蒸发浓缩，以固相萃取小柱纯化处理，采用高效液相色谱-串联飞行时间质谱进行检测。结果通过比较给药前后的TOF总离子流图，对尿中推测的代谢物和标准物质的出峰时间及相关化合物选择离子扫描二级质谱图进行了比较分析，结果在尿中发现了7种代谢产物，系统分析了这些代谢产物的代谢转化规律及可能结构。结论大鼠尿中人参皂苷Rd的主要转化途径为氧化、水解、结合及异构化代谢反应。     

HPLC-ESI-ITMSn法鉴定麻黄碱及其大鼠体内主要代谢产物

目的建立快速灵敏的LC-ESI-ITMSⁿ分析检测麻黄碱及其大鼠体内代谢物的方法。方法以麻黄碱对照品对LC-ESI-ITMS²色谱及质谱条件进行了优化，分析总结其电喷雾质谱的一级电离规律和多级质谱裂解规律，以此作为麻黄碱大鼠体内代谢物分析鉴定的依据。健康大鼠空腹灌胃麻黄碱10 mg·kg^-1，收集0~48 h的尿样，经C₁₈小柱固相萃取分离纯化后，直接采用LC-ESI-ITMSⁿ方法对尿样进行测定。结果根据生物体内药物代谢转化规律及母体药物的色谱-质谱行为规律，在尿样中鉴定出3个第I相代谢产物，未发现第II相代谢产物。结论本方法灵敏、快速、选择性高、专属性好，可用于麻黄碱的代谢产物研究。     

“神奇戒烟灵”中吡啶的GC，GC／MS测定

利用气相色谱直接进样及气相色谱／质谱联机分析技术对戒烟灵中的吡啶进行了检测，并用外标法测定了吡啶的含量，方法简单、方便，结果准确、可靠。     

Determination of urinary pyrraline by solid-phase extraction and high performance liquid chromatography

Pyrraline is one of the advanced glycation end products formed under non-enzymatic and non-oxidative conditions in vivo. In this study, we developed a novel method for determination of urinary pyrraline using solid-phase extraction as a pretreatment procedure prior to determination by high performance liquid chromatography (HPLC). The Oasis HLB solid-phase extraction cartridge was used for pretreatment of urine samples without hydrolysis. The chromatogram obtained clearly revealed the peak for urinary pyrraline owing to prior removal of interfering substances in urine samples. The recovery rate of pyrraline was 97.2+/-3.3% (n=6). The mean excretion level of urinary pyrraline in healthy control (20-77 years old, n = 30) was 1.42+/-0.65 micromol/mmol creatinine, and the daily variation in the excretion level was considered to be insignificant. We propose the above procedure as a simple, rapid, and accurate method for determination of pyrraline levels in urine.     

Simultaneous measurement of liquid-phase and solid-phase transformation kinetics in rotating disc and channel flow cell dissolution devices

Solvent-mediated solid-phase transformations may occur during dissolution tests which complicates the evaluation of dissolution rates in cases of metastable drugs. The purpose of this study was to determine the effects of solvent-mediated transformations of theophylline anhydrate (TP (A)) on the intrinsic dissolution rate in simulated gastric fluid at pH 1.2. A combined method set-up for simultaneous measurement of the dissolved quantity of drug and the solid form composition was constructed from in situ Raman spectroscopy and UV-vis-spectrophotometry. Transformation kinetics in the traditional USP rotating disc (RD) dissolution apparatus was compared with the recently introduced channel flow cell (CFC). Solid-phase data, supported by scanning electron micrographs taken off-line, explained the changes in the intrinsic dissolution rates due to hydrate formation. Kinetic modelling showed that first order kinetics fitted the data in CFC, but the conversion in RD was strongly S-shaped. These differences were related to dissimilar hydrodynamic conditions and diffusion characteristics in the two dissolution testing devices. In situ solid-phase measurement during dissolution testing can largely improve the understanding of the dissolution results of metastable drugs. This information is valuable in drug candidate selection as well as in explaining and controlling the behaviour of drug substances in the final drug products.     

Analysis of heterocyclic amines in meat products by liquid chromatography – Tandem mass spectrometry

Heterocyclic amines (HCAs), a class made up of more than 25 compounds, are unintended hazardous substances that are generated by the heating or processing of proteinaceous foods at high temperatures. The International Agency for Research on Cancer (IARC) has classified four such HCAs (IQ, MeIQ, MeIQx, and PhIP) as being probable or possible human carcinogens. In this study, two sample preparation strategies, liquid–liquid extraction (LLE) with solid-phase extraction (SPE) and a rapid, easy, cheap, effective, rugged, and safe extraction (QuEChERS) method, were investigated for the determination of 11 types of HCAs in meat products by LC-MS/MS. The HCAs in the samples were first extracted with acetonitrile by LLE, and followed by SPE. In the case of QuEChERS extraction, acetonitrile is used as the LLME solvent, and PSA, C18EC and MgSO₄ were used as the dSPE sorbent. Both methods showed good performance with respect to precision (RSD < 15.15%), accuracy (79.80–117.64%), recovery (52.39–116.88%), limit of quantitation for a spiked meat extract (0.01–10 ppb) and correlation coefficients (>0.993). The QuEChERS extraction strategy provided a better linear dynamic range and superior sensitivity in comparison with the LLE-SPE approach. HCAs were successfully quantified in real samples using the two proposed approaches by LC-MS/MS.     

Humic-Like Substances in Air Pollution Particulates Correlate with Concentrations of Transition Metals and Oxidant Generation

Abstract

We tested the hypotheses that (1) an incomplete oxidation of carbon-based fossil fuels during their combustion produces humic-like substances (HIS), which can be present in air pollution particulates and confer a capacity to complex metals; (2) air pollution particulates collected on PM₁₀ filters can be associated with concentrations of first-row transition metals; (3) particulates can catalyze the production of free radicals by cycling these transition metals through two stable valence states; and (4) concentrations of transition metals and oxidant generation by air pollution particulates increase with the content of HLS associated with these particles. HLS were isolated by alkali extraction. The content of these substances in combustion products of coal, diesel, oil, and wood was 3.1 ± 0.8%, 4.7 ± 1.0%, 1.0 ± 0.1%, and 8.2 ± 0.6%, respectively. Similarly, filters with sequestered air pollution particulates contained HLS ranging from 0.0 to 7.1%. Elemental analysis of these materials isolated from both products of fuel combustion and sequestered particulate disclosed values of C, H, N, and O consistent with an HLS. There were correlations between HLS content and ionizable concentrations of metals, quantified using inductively coupled plasma emission spectroscopy, associated with particulates sequestered on filters. Similarly, HLS content correlated with the absorbance of oxidized products of deoxyribose, demonstrating an affiliation between these substances and free radical generation by sequestered particulate. We conclude that HLS, a potential organic metal chelator, can be isolated from air pollution particulates. Concentrations of acid-soluble transition metals and in vitro oxidant generation correlated with the content of these substances collected on filters.     

Analysis of heterocyclic amines in meat products by liquid chromatography – Tandem mass spectrometry

Heterocyclic amines (HCAs), a class made up of more than 25 compounds, are unintended hazardous substances that are generated by the heating or processing of proteinaceous foods at high temperatures. The International Agency for Research on Cancer (IARC) has classified four such HCAs (IQ, MeIQ, MeIQx, and PhIP) as being probable or possible human carcinogens. In this study, two sample preparation strategies, liquid–liquid extraction (LLE) with solid-phase extraction (SPE) and a rapid, easy, cheap, effective, rugged, and safe extraction (QuEChERS) method, were investigated for the determination of 11 types of HCAs in meat products by LC-MS/MS. The HCAs in the samples were first extracted with acetonitrile by LLE, and followed by SPE. In the case of QuEChERS extraction, acetonitrile is used as the LLME solvent, and PSA, C18EC and MgSO₄ were used as the dSPE sorbent. Both methods showed good performance with respect to precision (RSD < 15.15%), accuracy (79.80–117.64%), recovery (52.39–116.88%), limit of quantitation for a spiked meat extract (0.01–10 ppb) and correlation coefficients (>0.993). The QuEChERS extraction strategy provided a better linear dynamic range and superior sensitivity in comparison with the LLE-SPE approach. HCAs were successfully quantified in real samples using the two proposed approaches by LC-MS/MS.     

Determination of malondialdehyde in biological samples by solid-phase extraction and high-performance liquid chromatography

An analytical procedure for determination of malondialdehyde in tissue homogenates and blood serum was developed. A reaction with 2,4-dinitrophenylhydrazine is used followed by cleaning up of the derivative by solid-phase extraction. The samples were analyzed by isocratic high-performance liquid chromatography (HPLC) using a narrow-bore HPLC-column. A good separation of the 1-pyrazole peak from that of 2,4-dinitrophenylhydrazine was observed. A high linear dependence was established by the concentration of 1-pyrazole in the range of 10-5000 ng/ml. The detection limit of the method applied for tissue homogenates and blood serum was approximately 10 ng/ml or lower, and RSD of the method was 9% (n = 8). The peak of 1-pyrazole for these samples was well separated from the other matrix peaks. Experiments carried out evaluated that the solid-phase extraction might be an effective step of the sample preparation, significantly increasing the selectivity of the analysis and the life-time of the column. The method seems to be applicable for determination of malondialdehyde in different biological samples.     

Prevention of non-immune mediated transfusion-related acute lung injury; from blood bank to patient

Transfusion-related acute lung injury (TRALI) is a severe form of pulmonary insufficiency induced by transfusion. TRALI is the leading cause of transfusion-related death, and is caused by the infusion of either anti-leukocyte antibodies in plasma containing blood products or neutrophil priming substances that accumulate during storage of cellular blood products. Among these neutrophil priming substances are bioactive lipids, such as lyso-phosphatidylcholines (lysoPCs) and arachidonic acid, soluble CD40L (sCD40L) and possibly other, as yet unidentified substances. The accumulation of these substances during cellular blood product storage and their role in the induction of "non-immune mediated" TRALI pathogenesis are highly relevant for the current debate of the use of longer vs. shorter stored blood products. In this review, the accumulation of these different substances during storage, as well as their mode of action in inducing TRALI are discussed. In addition, different improvements in current blood banking procedures to prevent TRALI due to these non-immune mediators will be proposed.     

Solid-phase extraction and gas chromatographic- mass spectrometric determination of the veterinary drug xylazine in human blood

This paper presents a method for the determination of xylazine in whole blood using solid-phase extraction and gas chromatography-mass spectrometry. This technique required only 0.5 mL of sample, and protriptyline was used as internal standard (IS). Limits of detection and quantitation (LOQ) were 2 and 10 ng/mL, respectively. The method was found to be linear between the LOQ and 3.50 microg/mL, with correlation coefficients higher than 0.9922. Precision (intra- and interday) and accuracy were in conformity with the criteria normally accepted in bioanalytical method validation. The analyte was stable in the matrix for at least 18 h at room temperature and for at least three freeze/thaw cycles. Mean recovery, calculated at three concentration levels, was 87%. To the best of our knowledge, this is the first time that solid-phase extraction is used as sample preparation technique for the determination of this compound in biological media. Because of its simplicity and speed when compared to other extraction techniques, the herein described method can be successfully applied in the diagnosis of intoxications by xylazine.