新型荧光衍生试剂用于尿样中痕量游离雌二醇和雌三醇的反相高效液相色谱-荧光检测和质谱定性

合成了新型高灵敏度的荧光标记试剂10-乙基吖啶酮-2-磺酰氯(EASC)。采用EASC柱前衍生化实现了雌二醇(E2)和雌三醇(E3)的反相高效液相色谱(RP-HPLC)-荧光分析及柱后质谱鉴定。试剂EASC比丹磺酰氯(DNS-Cl)具有更高的紫外、荧光和质谱检测灵敏度,其荧光发光强度是丹磺酰氯的1000倍以上。EASC与E2和E3在NaHCO3缓冲液(pH 10.5)中,于60 ℃下反应3 min即可获得稳定的荧光产物,最大激发波长(λex)和最大发射波长(λem)分别为270 nm和430 nm。所建立的方法具有良好的重现性,线性回归系数大于0.9990;检出限(S/N=3)为31 fmol 和40 fmol。对实际根田鼠尿样中的雌二醇和雌三醇含量进行了测定,结果令人满意。     

EASC荧光标记和LC-APCI-MS检测环境水样中游离脂肪胺

采用新型荧光标记试剂10-乙基吖啶酮-2-磺酰氯(EASC)作为柱前衍生试剂, 在Hypersil BDS C18反相色谱柱上(4.6 mm×200 mm, 10 μm i.d.), 采用梯度洗脱在20 min内实现了12种EASC-脂肪胺衍生物的快速基线分离. 最佳检测波长为λex/λem=270 nm/430 nm. EASC与常用的Dansyl-Cl相比具有更强的光致发光特性(紫外和荧光): 紫外吸收强度之比为3.2∶1, 相对荧光强度之比为30.0∶1~105.4∶1, 荧光量子效率之比为43.0∶1. 通过荧光检测及离子阱大气压化学电离源的正离子模式获得了胺类组分的准确定量和相应的柱后质谱鉴定. 质谱灵敏度之比为1.6∶1~6.2∶1. 建立的方法对环境水样中脂肪胺类化合物的测定具有快速、准确和重现性良好等优点, 回归系数大于0.9995, 检出限为4.0~12.7 fmol.     

高效液相色谱-串联质谱法测定海水中雌酮、雌二醇、雌三醇

建立了测定海水中雌酮、雌二醇和雌三醇的高效液相色谱-串联质谱的分析方法。样品的提取方法为固相萃取,流动相为乙腈和0.1%氨水,梯度洗脱,流速0.2 mL/min,运行时间10 min。质谱采用负离子扫描模式,定量的碎片离子分别是:雌酮:269.02/144.99;雌二醇:271.04/182.96;雌三醇:287.03/170.94。仪器检出限均为0.001 ng,方法检出限均为0.2 ng/L。回收率分别是78.0~110.0%,82.2~103.2%,76.4~95.1%。该方法适用于海水中雌激素类物质的检测。     

液相色谱同位素稀释串联质谱法测定人血清中17β-雌二醇含量

研究建立了以人血清中E2-16,16,17-d3为内标测定17β-雌二醇的液相色谱/串联质谱(ID-LC/MS/MS)方法。血清样品经固相萃取装置(SPE)提取雌二醇,乙酸乙酯萃取净化,吹干复溶后用10-乙基吖啶酮-2-磺酰氯(EASC)进行衍生。以Agilent Eclipse XDB-C18色谱分离柱,乙腈、水梯度洗脱,使用电喷雾三重四极杆串联质谱的多重反应监测模式测定,以校准曲线法进行定量。所建立的液相色谱同位素稀释串联质谱法(ID-LC/MS/MS)对于分析血清17β-雌二醇的批内、批间RSD分别为0.29%～0.73%和0.18%～0.28%,回收率为99.6%～100.2%,采用IFCC RELA比对(JCTLM比对)样品进行了方法比较,测定结果与其他实验室相比偏差在0.8%范围内。方法可作为人血清中17β-雌二醇含量测量参考方法。     

气相色谱-质谱法测定尿及河底泥中的环境雌激素

报道了尿及河底泥中环境雌激素(壬基酚、双酚A、己烯雌酚、17α-乙炔基雌二醇)和内源性雌激素(17α-雌二醇、17β-雌二醇、雌三醇、雌酮)的气相色谱-质谱(GC-MS)测定法。尿样经盐酸溶液水解后用固相萃取(SPE)柱浓缩净化,底泥样品用甲醇-乙酸乙酯萃取。被测组分经五氟丙酸酐(PFPA)衍生化后用GC-MS进行定性定量检测。该法测定的峰面积的日内相对标准偏差为1.22%-5.55%,检出限为0.05-1.27 μg/L(或μg/kg)。被测组分的加标回收率除尿样中17α-乙炔基雌二醇和己烯雌酚分别为2     

固相萃取-超高效液相色谱-串联质谱法同时测定饲料中的3种雌激素

建立了固相萃取-超高效液相色谱-串联质谱(SPE-UPLC-MS/MS)同时测定饲料(预混合、配合和浓缩饲料)中3种雌激素(17β-雌二醇、苯甲酸雌二醇和戊酸雌二醇)的检测方法。饲料样品经乙腈提取,Heaion C₁₈固相萃取柱净化后,用ACQUITY UPLC BEH C₁₈色谱柱(50 mm×2.1 mm,1.7 μm)分离,乙腈和0.1%氨水溶液作为流动相进行梯度洗脱,多反应监测(MRM)模式检测,内标法定量。结果表明,17β-雌二醇和戊酸雌二醇在10~200 μg/L、苯甲酸雌二醇在5~200 μg/L范围内具有良好线性,相关系数(r)≥0.996。17β-雌二醇、苯甲酸雌二醇和戊酸雌二醇的检出限分别为7、5和7 μg/kg。样品的平均加标回收率为96.5%~102.0%。该法前处理操作简便、分析速度快、检出限低、准确度高,可用于饲料中3种雌激素的同时检测。     

亚胺连接的多孔共价有机骨架材料结合固相萃取-液相色谱-串联质谱检测蜂蜜中雌激素

以亚胺连接的多孔共价有机骨架材料(IL-COF-1)作为固相萃取的吸附剂,建立了液相色谱-串联质谱快速检测蜂蜜样品中痕量雌激素的方法。该研究选择雌二醇、己烯雌酚、雌三醇、β-雌二醇和炔雌醇5种雌激素作为目标分析物。在蜂蜜样品中添加雌激素,采用单因素优化法对影响萃取效果的重要因素进行优化,获得最佳条件:IL-COF-1用量为30 mg,样品流速为3 mL/min,样品溶液pH值为7,以5 mL的1%(v/v)氨水-甲醇溶液进行洗脱,流速为0.4 mL/min,萃取过程中不添加NaCl。采用高效液相色谱-三重四极杆质谱联用技术对提取物中的雌激素进行定量分析。以乙腈和5 mmol/L的乙酸铵溶液作为流动相进行梯度洗脱,经C18色谱柱分离,采用电喷雾离子源、质谱多反应监测和负离子扫描模式,实现了蜂蜜样品中5种雌激素的快速定性定量分析。在最佳条件下,方法验证结果中雌三醇、β-雌二醇和炔雌醇的线性范围为1~500 ng/g,雌二醇和己烯雌酚的线性范围为0.1~100 ng/g,相关系数(r)为0.9934~0.9972。检出限(S/N=3)为0.01~0.30 ng/g,定量限(S/N=10)为0.05~0.95 ng/g。添加50 ng/g 5种雌激素进行重复性实验,日内精密度相对标准偏差(RSD)为3.2%~6.6%,日间精密度RSD为4.2%~7.9%。基于IL-COF-1的固相萃取-液相色谱-串联质谱法具有快速准确、灵敏度高等特点,适用于蜂蜜中雌激素的分析和检测。将该方法应用于4个实际蜂蜜样品中雌激素的检测,均未检出目标物;在低中高3个水平下,5种雌激素的加标回收率为80.1%~115.2%,结果令人满意。     

同位素稀释-超高效液相色谱-串联质谱法同时测定精油中的7种雌性激素

建立了采用同位素稀释-超高效液相色谱-串联质谱同时快速测定精油中7种雌性激素(雌三醇、雌二醇、雌酮、炔雌醇、己二烯雌酚、己烷雌酚、己烯雌酚)的方法。样品中雌性激素用乙酸乙酯-正己烷(2:98, v/v)溶液提取后,经硅胶固相萃取小柱净化,通过ACQUITY UPLCTM BEH SHELD RP18色谱柱(100 mm×2.1 mm, 1.7 μm)、以水-乙腈作流动相梯度洗脱对7种雌性激素进行分离,采用串联质谱在负离子扫描方式下通过多反应监测(MRM)模式进行定性定量分析。以雌三醇-D3、雌二醇-D3、己烯雌酚-D6为内标,有效减少了样品基质的影响。该方法对精油中7种雌激素的检出限(LOD)为0.3～7 μg/kg,定量限(LOQ)为1～20 μg/kg。待测物与内标物定量离子的峰面积比值与待测物的质量浓度在20～500 μg/L范围内呈良好的线性关系,相关系数(r2)均大于0.997;在20～500 μg/kg范围内3个水平的加标平均回收率为88.5%～114.8%,日内精密度(以相对标准偏差计)(n=6)为4.8%～18.9%。应用该方法对浙江杭州地区不同超市或美容院随机采集的12份精油样品进行测定的结果显示,有1份样品含有雌二醇和雌酮,其余11份样品均未检出雌性激素。     

藏羚粪便中雌激素的提取及高效液相色谱含量测定

以CHCl3为萃取剂,从藏羚粪样中提取雌二醇、雌三醇两种雌激素.以丹磺酰氯为柱前衍生试剂,60 ℃下在加入NaHCO3缓冲液的乙腈溶液中反应3 min,得到稳定的衍生产物.在HypersiL BDS C18 (4.6 mm×200 mm,5 μm)色谱柱上,采用梯度洗脱对雌二醇和雌三醇衍生物进行了基线分离,紫外检测波长为220 nm.衍生物线性相关系数均大于0.9994,检出限为0.16～0.64 pmol.本实验建立了粪样中激素的提取和含量测定的方法,为极端环境下藏羚繁殖生物学的研究奠定基础.     

超高效液相色谱-串联质谱法测定肉制品中8种雌激素残留量

提出了超高效液相色谱-串联质谱法测定肉制品中8种雌激素(辛基酚、壬基酚、双酚A、己烯雌酚、雌酮、17β-雌二醇、17α-乙炔雌二醇和雌三醇)含量的方法。样品经乙酸乙酯提取两次,过HLB固相萃取柱净化后,将洗脱液氮吹至近干,残渣用甲醇-水(1+9)溶液溶解。采用AC-QUITYTMBEH C18色谱柱分离,用含0.1%(体积分数)甲酸的5mmol.L-1乙酸铵溶液和甲醇组成的流动相梯度洗脱。质谱测定中采用负离子电离方式,多反应监测模式。方法检出限(3S/N)在0.2～0.3μg.kg-1之间。方法的回收率在76.2%～108.3%之间,测定值的相对标准偏差(n=6)为4.3%～11.7%。     

溶剂化的热力学集团展开理论

把二元溶液的过剩内能（excess energy）分成溶剂-溶剂、溶剂-溶质及溶质-溶质相互作用部分。利用集团展开方法给出了二元溶液在正则系综的配分函数的表达式,利用该表达式得到了溶质的偏摩尔内能(partial molar energy)和偏摩尔熵(partial molar entropy)的表达式。在无限稀溶液情形,过剩偏摩尔内能的溶剂-溶剂部分又称重组织内能（reorganization energy）,它反映了溶质存在时对其周围溶剂分子之间的相互作用能的影响。研究表明,在溶质的粒子数密度相对较大时,溶质分子之间的相互作用将影响过剩偏摩尔内能的溶剂-溶剂部分,对于稀溶液,过剩偏摩尔内能的溶剂-溶剂部分与溶质的摩尔分数成线性关系。对低密度二元溶液,溶质的过剩偏摩尔内能和过剩偏摩尔熵也与溶质的摩尔分数成线性关系。     

Wetting for self-healing and electrowetting for additive manufacturing

Advanced additive manufacturing actively widens its tool box of wettability-related phenomena to be used in production of new items. Novel self-healing engineering materials incorporate vascular networks with two types of nanochannels: the one containing a resin monomer, whereas another one — a curing agent. If such nanocomposites are damaged locally, both types of channels are locally broken, and they release resin monomer and curing agent droplets. These droplets spread by wettability over the nanotextured matrix, touch each other, and coalesce, which triggers polymerization reaction and crack stitching. Wettability-facilitated droplet spreading is accompanied by liquid imbibition in the pores in the nanofiber network. Such process peculiarities are in focus in the present review. An additional process relevant in direct writing and 3D printing is electrowetting (EW). It stems from the change in the contact angle in response to the electric polarization of dielectric substrates. EW allows movement of droplets on horizontal, vertical, and inverse surfaces, which can significantly facilitate the existing direct writing and 3D printing technologies. Accordingly, EW is also in focus in the present review.     

Call for nominations for the Heinrich-Emanuel-Merck Award

News and Announcements

Call for nominations for the Heinrich-Emanuel-Merck Award     

Polymeric Lids for Microcontainers for Oral Protein Delivery

Oral delivery of proteins and peptides is one of the main challenges in pharmaceutical drug development. Microdevices have the possibility to protect the therapeutics until release is desired, avoiding losses by degradation. One type of microdevice is polymeric microcontainers. In this study, lysozyme is chosen as model protein and loaded into microcontainers with the permeation enhancer sodium decanoate (C10). The loaded microcontainers are sealed and functionalized by applying polymeric lids onto the cavity of the devices. The first lid is poly(lactic‐co‐glycolic) acid (PLGA) and on top of this either polyethylene glycol (PEG) or chitosan is applied (PLGA+PEG or PLGA+chitosan, respectively). The functionalization is evaluated in vitro for morphology, drug release, and mucoadhesive properties. These are coupled with in vitro and ex vivo studies using Caco‐2 cells, Caco‐2/HT29‐MTX‐E12 co‐cultures, and porcine intestinal tissue. PLGA+chitosan shows slower release compared to PLGA+PEG or only PLGA in buffer and the transport of lysozyme across cell cultures is not enhanced compared to the bulk powder. Microcontainers coated with chitosan or PEG demonstrate a three times stronger adhesion during ex vivo mucoadhesion studies compared to samples without coatings. Altogether, functionalized microcontainers with mucoadhesive properties and tunable release for oral protein delivery are developed and characterized.     

Bump-hunting for the proficiency tester--searching for multimodality

Kernel density estimation is a method for producing a smooth density approximation to a dataset and avoiding some of the problems associated with histograms. If it is used with a degree of smoothing determined by a fitness for purpose criterion, it can be applied to proficiency test data in order to test for multimodality in the z-scores. The bootstrap is an essential additional technique to determine how rugged the initially estimated kernel density is: the random resampling of the data in the bootstrap simulates a complete blind repeat of the proficiency test. In addition, useful estimates of the standard error of a mode can be thus obtained. It is suggested that a mode and its standard error can be used as an assigned value and its standard uncertainty.     

Advances for proficiency testing for genetic laboratory science

Nucleic acid based clinical genetic testing has undergone explosive growth in recent years due in large part to the human genome project. Characterization of the human genome has led to a molecular understanding of the pathogenesis of many human diseases, and ultimately to clinical molecular tests becoming routinely used to diagnose a wide diversity of diseases. This rapid growth in clinical molecular genetic testing coupled with the complexity of the analytical procedures underscores the necessity for proficiency testing (i.e. external quality assessment) to allow laboratories offering such services the ability to evaluate their analytical procedures via inter-laboratory comparisons. The American College of Medical Genetics (ACMG) in partnership with the College of American Pathologists (CAP) have been offering proficiency testing for clinical molecular genetics laboratories since 1995, and presently have more than 230 laboratories from 11 countries enrolled in this program. This paper describes the evolution of this program and several challenges encountered in the delivery of a proficiency testing program for laboratories offering clinical molecular genetic services. Received: 13 April 2002 Accepted: 18 July 2002     

A methodology for choosing parameters for ESR readout of alanine dosimeters for radiotherapy

Spectrometer settings for ESR readout of alanine dosimeters for radiotherapy have been investigated. Several ESR parameters were studied and determined. The main reason for this work is to choose the suitable parameters to increase signal-to-noise ratio and to reduce the uncertainty on ESR readout, which is one of the main components of uncertainty of alanine/ESR dosimetry system for radiotherapy. The new spectrometer settings have been applied for ESR readout of alanine dosimeters irradiated from 1 to 10 Gy. A higher signal-to-noise ratio has been achieved compared to our old spectrometer settings. The extended uncertainty (k=2) has been evaluated in the dose range 2–10 Gy (maximum uncertainty of 4.9% for 2 Gy, while minimum uncertainty of 1.4% for 10 Gy), which implies that the alanine/ESR dosimetry system can be applied to radiotherapy dose level that needs a global accuracy of 5%.