Chromatographic characterization of amphiphilic di‐ and tri‐block copolymers of poly(ethylene oxide) and poly(ε‐caprolactone)

Amphiphilic di‐ and tri‐block copolymers based on poly(ethylene oxide) as a hydrophilic segment and poly(ε‐caprolactone) as a hydrophobic part are synthesized by the ring‐opening polymerization of ε‐caprolactone while using poly(ethylene glycol)s and methoxy poly(ethylene glycol)s of varying molar masses as macro‐initiators. The synthesized block copolymers are characterized with respect to their total relative molar mass and its distribution by size exclusion chromatography. Liquid chromatography at critical conditions of both blocks is established for the analysis of individual block lengths and tracking presence of unwanted homopolymers of both types in the block copolymer samples. New critical conditions of polycaprolactone on reversed phase column are reported using organic mobile phase. The established critical conditions of polycaprolactone extended the applicable molar mass range significantly compared to already reported critical conditions of polycaprolactone in aqueous mobile phase. Block copolymers are also analyzed at critical conditions of poly(ethylene glycol). Complete analysis of the di‐ and tri‐block copolymers at corresponding critical conditions provided a fair estimate of molar mass of non‐critical block besides information regarding presence of homopolymers of both types in the samples.     

Shape‐memory polymer networks from oligo(ϵ‐caprolactone)dimethacrylates

Polymer networks showing a thermally induced shape‐memory effect were prepared through the crosslinking of oligo(?‐caprolactone)dimethacrylates under photocuring with or without an initiator. The influence of the molecular weight of the oligo(?‐caprolactone)dimethacrylates and the initiator concentration on the macroscopic properties of the polymer networks was investigated. The isothermal and nonisothermal crystallization behavior of the polymer networks was evaluated as a basic principle of the functionalization process. Shape‐memory properties such as the strain fixity and strain recovery rate were quantified with cyclic thermomechanical tensile experiments for different maximum elongations. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1369–1381, 2005     

化妆品中8种呋喃香豆素的高效液相色谱法检测及质谱确证

建立了同时测定化妆品中8种呋喃香豆素类化合物(8-羟基补骨脂素、补骨脂素、异补骨脂素、8-甲氧基补骨脂素、5-甲氧基补骨脂素、三甲沙林、欧前胡素和异欧前胡素)的高效液相色谱分析方法及液相色谱-串联质谱确证方法。膏霜类、水剂类、香波类、散粉类、唇膏类等不同类型的化妆品样品分别经适宜的提取溶液进行超声提取,提取液以离心处理后,取上清液经微孔滤膜过滤后测定。采用Agilent Zorbax SB-Phenyl色谱柱(250 mm×4.6 mm, 5 μm)分离,以甲醇-乙腈-水三元流动相梯度洗脱,流速1.0 mL/min,柱温30 ℃,检测波长250 nm。8-羟基补骨脂素的定量限为0.25 mg/kg,补骨脂素、异补骨脂素、8-甲氧基补骨脂素、5-甲氧基补骨脂素、三甲沙林、欧前胡素、异欧前胡素的定量限为0.5 mg/kg。在低、中、高3种加标水平下,8种待测组分的平均回收率为85.0%～105.8%,相对标准偏差为0.41%～7.90%。采用本方法在一日内不同时间点(6个时间点,每隔1 h测定一次)和不同日期(6 d内)测定混合标准溶液,得到8个目标物峰面积的日内精密度均小于1%,日间精密度均小于2%。该方法准确、简便、快速,适用于不同类型化妆品中8种呋喃香豆素类化合物的测定。     

反相高效液相色谱法分离2-(氟苯基)-5-甲基苯并恶唑和2-(氯苯基)-5-甲基苯并恶唑的位置异构体

基于商品化的普通色谱柱建立了2-(氟苯基)-5-甲基苯并恶唑和2-(氯苯基)-5-甲基苯并恶唑邻、间、对位置异构体的分离检测方法。色谱柱为Inertsil ODS-SP C₁₈(250 mm×4.6 mm, 5 μm),以乙腈(A)和水(B)为流动相,在60%A~80%A间线性梯度洗脱15 min,流速为1.5 mL/min,柱温40℃,检测波长为310 nm。在质量浓度为2~200 mg/L范围内,2-(氟苯基)-5-甲基苯并恶唑邻、间、对位的异构体、2-(氯苯基)-5-甲基苯并恶唑邻、间、对位的异构体具有良好的线性关系,6种化合物的检出限(S/N=3)依次为0.0307、0.0293、0.0315、0.0226、0.0237、0.0226 mg/L。该法既为5-甲基苯并恶唑与氟苯或氯苯碳氢活化偶联反应制备的异构体混合物提供了一个快速检测的方法,又为2-芳基苯并恶唑类异构体的分离检测提供了参考。     

32种氧化型染料的高效液相色谱定量及高效液相色谱-串联质谱确证方法北大核心CSCD

染发类产品中氧化型染料种类多,实际样品测定时干扰多,建立染发类产品中多种常用染料的测定方法,为该类产品的有效监管提供技术手段十分必要。该研究根据染料使用频率分组,采用能够屏蔽硅羟基和金属离子影响的C_(18)柱,优化了《化妆品安全技术规范》(2015年版)中32种染料的高效液相色谱法(HPLC)并建立了高效液相色谱-串联质谱(HPLC-MS/MS)确证方法。样品以10 g/L亚硫酸氢钠水溶液为抗氧化剂,用无水乙醇-水(1∶1,v/v)混合溶液冰浴超声提取10 min。HPLC方法采用甲醇、乙腈和磷酸盐缓冲液为流动相分两个液相色谱条件进行梯度洗脱分离,于280 nm波长下检测,其中一个HPLC条件中的相互干扰组分均在另一个HPLC条件下完全分离,避免了实际样品检测时组分间的干扰,并排除了32种以外的其他15种常用染料的干扰。HPLC-MS/MS方法分别采用5 mmol/L乙酸铵水溶液-乙腈和5 mmol/L乙酸水溶液-乙腈为正离子和负离子模式下的流动相,电喷雾离子模式下用多反应监测(MRM)模式进行定性和定量分析。HPLC和HPLC-MS/MS两个方法中,日内精密度和48 h内稳定性的相对标准偏差(RSD)<10%,回收率为82.6%~114.9%(RSD<10%)。HPLC方法中32种染料在大约10~500 mg/L范围内线性关系良好(r^(2)>0.99),检出限为9.7~40.1μg/g;HPLC-MS/MS方法中氢醌线性范围为2.0~79.7 mg/L,检出限为8.0μg/g,其他组分线性范围约为0.1~4 mg/L,检出限为0.01~0.4μg/g。采用HPLC、HPLC-MS/MS两个方法和《化妆品安全技术规范》方法同时测定实际样品,共检出16种染料,检出含量范围为58~25160μg/g。3个方法检测结果的RSD为1.9%~10.1%。该研究增加了HPLC-MS/MS确证方法,适应化妆品法定检验中的未知物确认程序;方法简便快速,结果准确,专属性强,具有较好的通用性和可操作性。     

高效液相色谱-电感耦合等离子体质谱联用检测食品中的五种硒形态

建立了高效液相色谱-电感耦合等离子体质谱(HPLC-ICP-MS)联用检测硒酸盐(SeVI)、亚硒酸盐(SeIV)、硒代蛋氨酸(SeMet)、硒代胱氨酸(SeCys2)和硒代乙硫氨酸(SeEt)的方法。采用Hamilton PRP X-100色谱柱（250 mm×4.6 mm, 5 μm）,使用5 mmol/L的柠檬酸溶液(pH 4.5)作为流动相,电感耦合等离子体质谱(ICP-MS)检测,在21 min内可以完全分离5种硒形态。各形态硒的线性相关系数均大于0.9995, SeVI、SeIV、SeMet、SeCys2、SeEt的检出限分别为0.4、0.4、5.6、0.9、1.2 μg/L。探讨了不同提取方法的提取效果,鲜蘑菇和猪肉样品加标回收实验表明,对水溶性良好的无机硒和硒代蛋氨酸而言,采用柠檬酸溶液提取的效果非常好,SeIV和SeVI的回收率均在100%左右,SeMet的回收率为85.0%～95.3%;用蛋白酶水解提取,SeCys2和SeEt的回收率为79.9%～91.5%。该方法可完全满足食品中这5种硒形态的准确定量分析。     

Aminated PCL‐based copolymers by chemical modification of poly(α‐iodo‐ε‐caprolactone‐co‐ε‐caprolactone)

A novel method is proposed to access to new poly(α‐amino‐ε‐caprolactone‐co‐ε‐caprolactone) using poly(α‐iodo‐ε‐caprolactone‐co‐ε‐caprolactone) as polymeric substrate. First, ring‐opening (co)polymerizations of α‐iodo‐ε‐caprolactone (αIεCL) with ε‐caprolactone (εCL) are performed using tin 2‐ethylhexanoate (Sn(Oct)₂) as catalyst. (Co)polymers are fully characterized by ¹H NMR, ¹³C NMR, FTIR, SEC, DSC, and TGA. Then, these iodinated polyesters are used as polymeric substrates to access to poly(α‐amino‐ε‐caprolactone‐co‐ε‐caprolactone) by two different strategies. The first one is the reaction of poly(αIεCL‐co‐εCL) with ammonia, the second one is the reduction of poly(αN₃εCL‐co‐εCL) by hydrogenolysis. This poly(α‐amino‐ε‐caprolactone‐co‐ε‐caprolactone) (F_αNH2εCL < 0.1) opens the way to new cationic and water‐soluble PCL‐based degradable polyesters. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6104–6115, 2009     

Enantiomeric differentiation of β‐amino alcohols under electrospray ionization mass spectrometric conditions

The enantiomeric differentiation of a series of chiral β‐amino alcohols (A) is attempted, for the first time, by applying the kinetic method using L‐proline, L‐tryptophan, 4‐iodo‐L‐phenylalanine or 3, 5‐diiodo‐L‐tyrosine as the chiral references (Ref) and Cu²⁺ or Ni²⁺ ion (M) as the central metal ion. The trimeric diastereomeric adduct ions, [M+(Ref)₂+A‐H]⁺, formed under electrospray ionization conditions, are subjected for collision‐induced dissociation (CID) experiments. The products ions, formed by the loss of either a reference or an analyte, detected in the CID spectra are evaluated for the enantiomeric differentiation. All the references showed enantiomeric differentiation and the R_chiral values are better for the aromatic alcohols than for aliphatic alcohols. Notably, the R_chiral values of the aliphatic amino alcohols enhanced when Ni²⁺ is used as the central metal ion. The experimental results are well supported by computational studies carried out on the diastereomeric dimeric complexes. The computational data of amino alcohols is correlated with that of amino acids to understand the structural interaction of amino alcohols with reference molecule and central metal ion and their role on the stabilization of the dimeric complexes. Application of flow injection MS/MS method is also demonstrated for the enantiomeric differentiation of the amino alcohols. Copyright © 2014 John Wiley & Sons, Ltd.     

Accurate identification of dimers from α‐pinene oxidation using high‐resolution collision‐induced dissociation mass spectrometry

Interest in mass spectrometry of highly oxidized dimers from α‐pinene oxidation has increased in the atmospheric chemistry field. Here, we apply high‐resolution collision‐induced dissociation mass spectrometry (HR‐CID‐MS) with an atmospheric pressure ionization source to investigate in detail how α‐pinene‐derived dimers are detected and identified by MS. The resulting HR‐CID spectra and specific fragmentation patterns suggest that a large fraction of dimer ions detected in full‐scan mass spectra can be hydrogen‐bonded artifact clusters and the residual small fraction includes covalently bonded actual dimers. We also show how individual fractions of the artifact clusters and actual dimers are calculated using the HR‐CID spectra.     

Metabolites study on 5‐O‐methylvisammioside in vivo and in vitro by ultra high performance liquid chromatography coupled to quadrupole time‐of‐flight mass spectrometry

5‐O‐Methylvisammioside is one of major chromones of Radix Saposhnikoviae possessing definite pharmacological activities, but there are few reports with respect to the metabolism of 5‐O‐methylvisammioside. In this work, metabolites in vivo were explored in male Sprague‐Dawley rats and in vitro investigated on rat intestinal bacteria incubation model and were identified by using ultra high performance liquid chromatography/quadrupole time‐of‐flight mass spectrometry. An online data acquisition method based on a multiple mass defect filter and dynamic background subtraction was developed to trace all probable metabolites. As a result, 26 metabolites in vivo (including 18, 15, 10, and 10 in rat urine, faece, bile, and blood) and 7 metabolites in vitro were characterized, respectively. Additionally, the main metabolic pathways in vivo and in vitro, including deglycosylation, deglycosylation + demethylation, deglycosylation + oxidation, N‐acetylation, and sulfate conjugation, were summarized by calculating the relative content of each metabolite. The obtained results significantly enriched our knowledge about 5‐O‐methylvisammioside metabolism and will lead to a better understanding of its safety and efficacy.     

Screening and identification of α‐glucosidase inhibitors from Shenqi Jiangtang Granule by ultrafiltration liquid chromatography and mass spectrometry

Shenqi Jiangtang Granule, a well‐known traditional Chinese herbal preparation, has been widely used for the treatment of type II diabetes mellitus. In this work, an ultrafiltration liquid chromatography with quadrupole time‐of‐flight mass spectrometry method was proposed for the rapid identification of bioactive ingredients from Shenqi Jiangtang Granule using α‐glucosidase as an example. First, the chemical profile of this preparation was clarified, including 37 saponins, 17 flavonoids, 37 lignans, and seven other compounds. After incubation with α‐glucosidase in vitro, the methanol extract with an IC₅₀ value of 0.19 mg/mL exhibited significant inhibitory activity. Then, 18 specific binding peaks were screened, and 15 peaks were identified. Among these, ten compounds were reported to have potential α‐glucosidase inhibitory activity for the first time. Subsequently, the inhibitory activities of these active compounds were evaluated by ultraviolet spectrophotometry with p‐nitrophenyl α‐d‐ glucopyranoside as a substrate. As a result, gomisin J and gomisin D exhibited stronger α‐glucosidase inhibitory activities than other active compounds with IC₅₀ values of 77.69 and 133.85 μM, respectively. The results demonstrated that the integrated ultrafiltration liquid chromatography with mass spectrometry method was an effective and powerful tool for the discovery of active ingredients in Shenqi Jiangtang Granule.     

Coupling nanoliter high‐performance liquid chromatography to inductively coupled plasma mass spectrometry for arsenic speciation

Nanoliter high‐performance liquid chromatography shows low consumption of solvents and samples, offering one of the best choices for arsenic speciation in precious samples in combination with inuctively coupled plasma mass spectrometry. A systematic investigation on coupling nanoliter high‐performance liquid chromatography to inductively coupled plasma mass spectrometry from instrument design to injected sample volume and mobile phase was performed in this study. Nanoflow mobile phase was delivered by flow splitting using a conventional high‐pressure pump with reuse of mobile phase waste. Dead volume was minimized to 60 nL for the sheathless interface based on the previously developed nanonebulizer. Capillary columns for nanoliter high‐performance liquid chromatography were found to be sensitive to sample loading volume. An apparent difference was also found between the mobile phases for nanoliter and conventional high‐performance liquid chromatography. Baseline separation of arsenite, arsenate, monomethylarsenic, and dimethylarsenic was achieved within 11 min on a 15 cm C₁₈ capillary column and within 12 min on a 25 cm strong anion exchange column. Detection limits of 0.9–1.8 μg/L were obtained with precisions variable in the range of 1.6–4.2%. A good agreement between determined and certified values of a certified reference material of human urine (GBW 09115) validated its accuracy along with good recoveries (87–102%).     

Quantification of bisphenol A and its selected analogs in serum using pre‐column derivatization with high‐performance liquid chromatography and tandem mass spectrometry

Due to regulation of the use of bisphenol A, several analogs serving as bisphenol A replacements have drawn substantial attention for their adverse health effects. To investigate their occurrence in humans and identify possible pollution sources, it is necessary to develop a sensitive method for total bisphenols detection. Thus, a method based on enzymolysis and liquid‐liquid extraction followed by molecularly imprinted polymer solid‐phase extraction and pre‐column derivatization with high‐performance liquid chromatography and tandem mass spectrometry was proposed. The developed method exhibited superior selectivity and sensitivity. The matrix effect can be eliminated to a great extent. The method detection limits for eight bisphenols were 0.05～0.19 ng/mL. Satisfactory recoveries (71～119%) were obtained by spiking bovine serum at three levels (0.8, 8 and, 20 ng/mL). The method was successfully applied to determine total bisphenols in the serum samples of children. Bisphenol A, bisphenol F, bisphenol S, bisphenol B and bisphenol F were detected with concentrations from below the method detection limit to 1.65, 0.45, 0.79, 2.04 and 0.17 ng/mL, respectively. These results indicate that bisphenol A remains the major pollutant among the studied bisphenols in children, whereas threats from bisphenol A analogs should also be monitored.     

Chemical fingerprint of Ganmaoling granule by double‐wavelength ultra high performance liquid chromatography and ultra high performance liquid chromatography with quadrupole time‐of‐flight mass spectrometry

A method incorporating double‐wavelength ultra high performance liquid chromatography with quadrupole time‐of‐flight mass spectrometry was developed for the investigation of the chemical fingerprint of Ganmaoling granule. The chromatographic separations were performed on an ACQUITY UPLC HSS C₁₈ column (2.1 × 50 mm, 1.8 μm) at 30°C using gradient elution with water/formic acid (1%) and acetonitrile at a flow rate of 0.4 mL/min. A total of 11 chemical constituents of Ganmaoling granule were identified from their molecular weight, UV spectra, tandem mass spectrometry data, and retention behavior by comparing the results with those of the reference standards or literature. And 25 peaks were selected as the common peaks for fingerprint analysis to evaluate the similarities among 25 batches of Ganmaoling granule. The results of principal component analysis and orthogonal projection to latent structures discriminant analysis showed that the important chemical markers that could distinguish the different batches were revealed as 4,5‐di‐O‐caffeoylquinic acid, 3,5‐di‐O‐caffeoylquinic acid, and 4‐O‐caffeoylquinic acid. This is the first report of the ultra high performance liquid chromatography chemical fingerprint and component identification of Ganmaoling granule, which could lay a foundation for further studies of Ganmaoling granule.     

Melting and crystallization behavior of polyhedral oligomeric silsesquioxane‐capped poly(ε‐caprolactone)

In this study, we investigated the melting and crystallization behavior of polyhedral oligomeric silsesquioxane (POSS)‐capped poly(ε‐caprolactone) PCL with various lengths of PCL chains by means of X‐ray diffraction and differential scanning calorimetry. This organic–inorganic macromolecule possesses a tadpole‐like structure in which the bulky POSS cage is the “head” whereas PCL chain the “tail”. The novel organic–inorganic association result in the significant alterations in the melting and crystallization behavior of PCL. The POSS‐terminated PCL displayed the enhanced equilibrium melting points compared to the control PCL. Both the overall crystallization rate and the spherulitic growth rate of the POSS‐terminated PCLs increased with increasing the concentration of POSS (or with decreasing length of PCL chain in the hybrids). The analysis of Avrami equation shows that the crystallization of the POSS‐terminated PCL preferentially followed the mechanism of spherulitic growth with instantaneous nuclei. It is found that the folding free energy of surface for the POSS‐terminated PCLs decreased with increasing the concentration of POSS. It is found that the folding free energy of surface for the POSS‐terminated PCLs decreased with increasing the concentration of POSS. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2201–2214, 2007     

Detection of buffalo mozzarella adulteration by an ultra‐high performance liquid chromatography tandem mass spectrometry methodology

Over the past years, LC–MS‐based approaches have gained a growing interest in food analysis by using different platforms and methodologies. In particular, enhanced selectivity and sensitivity of multiple reaction monitoring (MRM) scan function offer powerful capabilities in detecting and quantifying specific analytes within complex mixtures such as food matrices. The MRM approach, traditionally applied in biomedical research, is particularly suitable for the detection of food adulteration and for the verification of authenticity to assure food safety and quality, both recognized as top priorities by the European Union Commission. Increasingly stringent legislation ensure products safety along every step ‘from farm to fork’, especially for traditional foods designed with the Protected Designation of Origin certification. Therefore, there is a growing demand of new methodologies for defining food authenticity in order to preserve their unique traits against frauds. In this work, an ultra performance liquid chromatopgraphy‐electrospray ionization‐tandem mass spectrometry (MS/MS) methodology based on MRM has been developed for the sensitive and selective detection of buffalo mozzarella adulteration. The targeted quantitative analysis was performed by monitoring specific transitions of the phosphorylated β‐casein f33‐48 peptide, identified as a novel species‐specific proteotypic marker. The high sensitivity of MRM‐based MS and the wide dynamic range of triple quadrupole spectrometers have proved to be a valuable tool for the analysis of food matrices such as dairy products, thus offering new opportunities for monitoring food quality and adulterations. Copyright © 2012 John Wiley & Sons, Ltd.     

高效液相色谱-串联质谱法检测红葡萄酒中功效成分

建立了高效液相色谱-串联质谱法快速测定葡萄酒中白藜芦醇、黄酮类、多酚类功效成分的分析方法。葡萄酒样品直接稀释后进样,用C18柱进行分离,以乙腈-0.1%(体积分数)甲酸水溶液为流动相进行梯度洗脱,通过多反应监测(MRM)模式进行检测。13种功效成分在各自线性范围内呈良好的线性关系,相关系数均大于0.99。除表没食子儿茶素、没食子儿茶素、儿茶素没食子酸酯、花旗松素的检出限为1.0、1.0、3.0、3.0μg/L外,其他9种化合物的检出限均小于1.0μg/L。回收率为80.9%~112.3%,相对标准偏差小于10%。该方法快速、准确、灵敏度高,适用于葡萄酒中功效成分的快速分析。对实际样品的检测表明,所测葡萄酒样品中均含有儿茶素、表儿茶素、表没食子儿茶素、没食子儿茶素、表儿茶素没食子酸酯/儿茶素没食子酸酯、白藜芦醇、大豆黄素等功效成分,不同品种葡萄酒中这些功效成分含量差异显著。     

Metabolic profiling comparison of isovitexin in normal and kidney stone model rats by ultra‐high‐performance liquid chromatography coupled to quadrupole time‐of‐flight mass spectrometry

Isovitexin, a bioactive flavonoid constituent isolated from Desmodii Styracifolii, is considered an adjuvant for antiurolithiasis diseases. In this study, an ultra‐high‐performance liquid chromatography coupled with hybrid triple quadruple time‐of‐flight mass spectrometry method was developed to characterize and compare the metabolic profiling of isovitexin experimented on normal and kidney stone model rats. The comparative research indicated that 28 metabolites (18 phase I and 10 phase II) in normal rats and 33 metabolites (20 phase I and 13 phase II) in kidney stone model rats were initially identified. The results of relative quantitative determination reflected that the contents of metabolites produced by deglycosylation, reduction, and isomerization in kidney stone model rats were greater than those in healthy rats. Instead, the levels of oxidative and dehydrogenated metabolites in normal groups were higher than those in kidney stone model groups. The results of this study are valuable and important for understanding the metabolic process of isovitexin in clinical application, and especially the metabolism study in kidney stone model rats could provide a beneficial reference for the further search of effective substances associated with the treatment of kidney stones.     

基于高效液相色谱定量指纹图谱和液相色谱-质谱联用定量的酸枣仁提取物质量考察

酸枣仁具有显著的改善睡眠和抗焦虑等作用,其提取物在助眠类功能食品开发中应用前景广阔。但目前市场上酸枣仁提取物质量参差不齐,缺乏统一标准,企业在使用时面临较大的质量风险,因此亟须建立一种准确、全面的内控质量评价方法。针对酸枣仁提取物中黄酮和皂苷两类主要活性成分紫外响应差异巨大且水提物中皂苷成分含量低的问题,该研究建立了酸枣仁水提物HPLC定量指纹图谱方法,共标定了8个共有峰。通过对照品指认、文献比对以及高效液相色谱-四极杆飞行时间质谱数据解析,8个共有峰均为黄酮类化合物,该方法可同时实现7种黄酮成分的半定量对比分析和斯皮诺素的含量测定;采用超高效液相色谱-三重四极杆质谱,在正离子模式下,以多反应监测扫描方式可实现酸枣仁皂苷A和B的含量测定;最终以雷达图展现上述10种成分的半定量和定量数据。应用上述方法,该研究对比分析了实验室自制的3批酸枣仁水提物和15家供应商的15批提取物样品。结果显示,实验室自制的3批酸枣仁水提物虽然原料来自不同饮片企业,但总体差异性不大,而不同厂家提供的酸枣仁提取物样品成分含量差异巨大,提示不同厂家存在辅料稀释、理枣仁掺假和醇提或纯化富集等情况。该法为企业制定内控质量标准和筛选合格供应商提供了依据。     

Identification of phase I and II metabolites of the new designer drug α‐pyrrolidinohexiophenone (α‐PHP) in human urine by liquid chromatography quadrupole time‐of‐flight mass spectrometry (LC‐QTOF‐MS)

Pyrrolidinophenones represent one emerging class of newly encountered drugs of abuse, also known as ‘new psychoactive substances’, with stimulating psychoactive effects. In this work, we report on the detection of the new designer drug α‐pyrrolidinohexiophenone (α‐PHP) and its phase I and II metabolites in a human urine sample of a drug abuser. Determination and structural elucidation of these metabolites have been achieved by liquid chromatography electrospray ionisation quadrupole time‐of‐flight mass spectrometry (LC‐ESI‐QTOF‐MS). By tentative identification, the exact and approximate structures of 19 phase I metabolites and nine phase II glucuronides were elucidated. Major metabolic pathways revealed the reduction of the ß‐keto moieties to their corresponding alcohols, didesalkylation of the pyrrolidine ring, hydroxylation and oxidation of the aliphatic side chain leading to n‐hydroxy, aldehyde and carboxylate metabolites, and oxidation of the pyrrolidine ring to its lactam followed by ring cleavage and additional hydroxylation, reduction and oxidation steps and combinations thereof. The most abundant phase II metabolites were glucuronidated ß‐keto‐reduced alcohols. Besides the great number of metabolites detected in this sample, α‐PHP is still one of the most abundant ions together with its ß‐keto‐reduced alcoholic dihydro metabolite. Monitoring of these metabolites in clinical and forensic toxicology may unambiguously prove the abuse of the new designer drug α‐PHP. Copyright © 2015 John Wiley & Sons, Ltd.