快速溶剂提取-高效液相色谱法测定PM2.5中16种多环芳烃

建立大气细颗粒物(PM2.5)中16种多环芳烃(PAHs)的快速溶剂提取-直接进样-高效液相色谱测定方法.PM2.5经玻璃纤维滤膜收集,采样后的滤膜直接用乙腈经快速溶剂萃取仪提取,以乙腈和水作为流动相,提取液通过ZORBAX Eclipse PAH液相色谱柱分离,紫外串联荧光检测器检测.16种PAHs分离效果良好,在0.025~5.000μg/mL范围内线性相关系数r≥0.9998,方法加标回收率为78.3%~113.2%,相对标准偏差为0.5%~9.5%,检出限为0.007~0.062 ng/m3.本方法操作简便、快速、准确、灵敏,适于PM2.5中16种PAHs的同时测定.     

分散固相萃取净化/高效液相色谱法测定婴幼儿奶粉与米粉中15种多环芳烃

建立了高效液相色谱-荧光检测法同时测定婴幼儿奶粉和米粉中15种多环芳烃的检测方法。样品经乙腈提取,PSA分散固相萃取净化;乙腈-水梯度洗脱,Waters PAH专用柱分离,荧光检测器检测,外标法定量。在最优条件下,15种多环芳烃均得到有效分离,线性范围为1.0~50μg/L,相关系数均大于0.995,方法检出限(LODs,S/N=3)为0.05~0.3μg/kg,回收率为86.5%~106.8%,精密度(RSD,n=6)为0.7%~7.5%。该方法操作简单、灵敏度高,适用于婴幼儿奶粉和米粉中多环芳烃的检测。     

气相色谱-三重四极杆串联质谱法检测环境空气中的多环芳烃

建立了气相色谱-三重四极杆串联质谱检测环境空气中多环芳烃的方法,并利用同位素稀释法对多环芳烃进行了测定。将该方法应用于华南地区某大型石化企业周边环境空气中多环芳烃的检测,并与气相色谱-质谱方法进行了对比。结果表明,该方法的仪器检出限(0.01~0.15μg/L)和定量限(0.03~1.5μg/L)均优于气相色谱-质谱法(0.1~0.8μg/L和0.3~3.5μg/L),并有更好的灵敏度与选择性。当利用气相色谱-质谱作为检测手段时,回收率指示物氘代菲和进样内标六甲基苯均受到了杂质的严重干扰,影响了定量结果的准确性,而三重四极杆串联质谱很好地解决了这些问题。实际样品分析时,标准曲线中16种多环芳烃相对响应因子的相对标准偏差为2.60%~15.6%,氘代化合物的回收率为55.2%~82.3%,空白加标样品的回收率为98.9%~111%,平行样品的相对标准偏差为6.50%~18.4%,采样空白含量范围为未检出~44.3 pg/m3,实验室空白含量范围为未检出~36.5pg/m3。上述研究表明,分析环境空气中的多环芳烃时,气相色谱-三重四极杆串联质谱方法值得推广。     

凝固漂浮有机液滴-分散液液微萃取结合高效液相色谱法同时测定地表水中多环芳烃和酞酸酯

多环芳烃和酞酸酯是国际公认的优控污染物,因此准确快速地测定水中多环芳烃和酞酸酯非常重要。凝固漂浮有机液滴-分散液液微萃取（DLLME-SFO）是一种简便、快速、环境友好、灵敏度高的样品前处理技术。采用DLLME-SFO同时测定地表水中多环芳烃和酞酸酯的分析方法鲜有报道。该文采用凝固漂浮有机液滴-分散液液微萃取富集技术,结合高效液相色谱紫外/荧光法,建立了同时测定地表水中16种多环芳烃和6种酞酸酯的分析方法。考察优化了影响萃取效率的主要因素,包括萃取剂的种类和用量、分散剂的种类和用量、萃取时间和离子强度等。优化后的萃取实验条件为：5.0 mL水样,10 μL十二醇为萃取溶剂,500 μL甲醇为分散溶剂,涡旋振荡时间2 min,氯化钠用量0.2 g。目标化合物经多环芳烃专用色谱柱（SUPELCOSIL^TM LC-PAH,150 mm×4.6 mm,5 μm）结合乙腈-水梯度洗脱分离,16种多环芳烃除苊烯外采用荧光检测,苊烯和6种酞酸酯采用紫外检测,外标法定量。结果表明,22种目标化合物的基质加标回收率为60.2%~113.5%,相对标准偏差为1.9%~14.3%;多环芳烃和酞酸酯的检出限分别为0.002~0.07 μg/L和0.2~2.2 μg/L;多环芳烃和酞酸酯的定量限分别为0.006~0.23 μg/L和0.8~7.4 μg/L。该方法简便、快速,环境友好,灵敏度高,可用于地表水中多环芳烃和酞酸酯的快速分析检测。     

高效液相色谱-荧光/紫外串联测定鱼体中硝基苯同系物

采用高效液相色谱-荧光/紫外检测器串联测定鱼体中7种硝基苯同系物。通过色谱柱、荧光激发和发射波长等条件的优化,实现7种硝基苯同系物组分的完全分离,并通过荧光-紫外串联检测提高了定性的准确度。结果表明:7种硝基苯的峰面积与其质量浓度在0.1～2.0μg/mL范围内呈线性关系,相关系数均大于0.999;检出限为6.3～151.0ng/g;方法的回收率为71.48%～90.14%;相对标准偏差在4.38%～13.29%范围。     

气相色谱-串联质谱法测定土壤中多环芳烃和多氯联苯

研究土壤中持久性有机污染物的含量可以为区域环境治理和来源解析提供基础数据。本文通过固相萃取结合气相色谱-串联质谱法建立了16种多环芳烃和15种多氯联苯的检测方法,并优化了固相萃取净化方法、色谱条件以及质谱碰撞能量。结果表明16种多环芳烃和15种多氯联苯的标准曲线线性关系良好,方法线性相关系数r~20.999,方法的检出限为0.1~2.5μg·kg~(-1),16种多环芳烃的平均加标回收率范围为62.5%~113.5%,相对标准偏差在2.3%~8.2%之间,15种多氯联苯的平均加标回收率范围为62.6%~91.4%,相对标准偏差在5.2%~7.8%之间。方法的准确度和精密度较高,通过对实际样品的测定,说明该方法具有较低的检出限及较强的抗干扰能力,能满足土壤中多环芳烃和多氯联苯的检测要求。     

在线固相萃取/高效液相色谱法检测熏烤鱼及熏烤肉制品中的多环芳烃

基于在线净化富集技术,建立了熏烤鱼和熏烤肉制品中15种欧盟优控多环芳烃的在线固相萃取/高效液相色谱-紫外/荧光(Online-SPE/HPLC-UV/FLD)检测方法。对提取溶剂和流动相进行优化,样品采用乙腈-丙酮(6∶4)匀浆处理,超声提取后,在线固相萃取柱Chrom Spher Pi(80 mm×3 mm)净化富集,反相C18PAH专用柱(250 mm×4.6 mm i.d.,5μm)分离,水、乙腈和异丙醇梯度洗脱,紫外和荧光检测器检测。结果表明,15种多环芳烃在相应的浓度范围内线性良好(r20.999);检出限为0.03~8.33μg/kg;熏烤鱼的回收率为67.4%~107.2%,相对标准偏差(RSD)为0.2%~7.7%;熏烤肉的回收率为71.8%~110.5%,RSD为0.8%~8.9%。经FAPAS质控样品验证,所测化合物种类和浓度范围均满足要求。     

离子色谱电导-紫外检测器串联法测定海洋沉积物孔隙水中的4种阴离子

建立了电导-紫外检测器串联离子色谱法测定海洋沉积物孔隙水中的NO_2~-,NO-3,PO_4~(3-)和SO2-4,选用高通量色谱柱和保护柱,以1.9 mmol/L Na HCO3-3.2 mmol/L Na2CO3为淋洗液,采用电导和紫外检测器同时检测4种离子,抑制电导检测器检测PO_4~(3-)和SO2-4,紫外检测器检测NO_2~-和NO-3以消除高含量Cl-的影响。在优化的色谱条件下,单个样品测试时间为6 min,NO_2~-,NO-3,PO_4~(3-)和SO2-4的方法检出限分别为17.2,32.0,144和22.7μg/L。对2个真实样品进行检测,各离子的相对标准偏差(RSD,n=6)为1.5%~5.3%,对样品进行加标回收实验,加标回收率为95.6%~105.6%。     

漩涡辅助液液微萃取-气相色谱法测定水样中痕量多环芳烃

建立了漩涡辅助分散液液微萃取(VAEDLLME)结合气相色谱测定环境水样中12种多环芳烃的方法。对萃取剂种类和体积、漩涡时间以及盐浓度的影响等参数进行优化。实验结果表明,方法线性范围为0.1~5.0μg/L,相关系数r≥0.9851,检出限为0.001~0.01μg/L,加标回收率为95.0%~124.4%,相对标准偏差(RSD)为1.4%~27%。方法适用于环境水样中12种多环芳烃的分析检测。     

高效液相色谱法测定煤沥青中16种多环芳烃

建立了煤沥青中苯并[a]蒽、苯并[a]芘等16种多环芳烃(PAHs)的高效液相色谱分离检测方法。以甲苯为溶剂对煤沥青进行萃取,萃取液处理后经柱层析分离,层析洗脱液分组回收,然后进行液相色谱分析。采用ZORBAX Eclipse PAH柱分离,以乙腈-水为流动相进行梯度洗脱,紫外检测器进行测定。结果表明,16种PAHs的线性范围为0.5~20 mg/L,相关系数(r)均大于0.999,检出限为0.0031~0.035μg/L,方法的回收率为97.2%~108.3%,相对标准偏差(RSD)为0.18%~3.5%。方法用于两种不同煤沥青中16种PAHs含量的测定,两种煤沥青中16种PAHs的含量分别为107.86 g/kg和103.71 g/kg,其中苯并[a]芘的含量分别为11.86 g/kg和13.82 g/kg。     

Indirect Electrosorptive Detection via Kinetic Facilitation in Ion Chromatography

Abstract

A new technique based on electrosorption is presented for the determination of selected anions in ion chromatography. Unlike conventional methods, which are based on the measurement of nonfaradaic currents, the present method utilizes a kinetic facilitation imparted to the electroreduction of a cationic “adsorbate probe” by specifically adsorbed anions, and hence involves the measurement of faradaic currents. Amminated, transition-metal salts of Co(III) have been found most useful as adsorbate probes for this application. The current enhancement-analyte concentration response curves obtained were determined to be linear over a limited range at mercury, but show curvature at virtually all concentrations at silver. Detection limits for this technique are slightly higher than those realized using more conventional double-layer capacitance methods. A brief discussion of the future prospects for this new approach is given.     

单碱基多样性的非测序检测

单碱基多样性（SNP）是最常见的基因突变形式之一,经研究证明与很多疾病相关。虽然测序是检测SNP的重要方法,但其需要检测仪器,且检测时间较长,限制了其临床应用。本文综述了SNP的常见非测序分析方法。首先讨论了检测的热力学问题,并归纳了主要的检测策略：基于杂交的检测,基于链取代反应的检测和酶介导的检测。在三维均相检测方法中,主要介绍了不同信号开关策略,如荧光开关、酶识别开关和场效应开关。三维原位检测不仅能检测SNP,还能提供其细胞定位信息,在细胞异质性较高时更具优势。二维界面检测的识别反应速率和杂交效率受到一定影响,但界面检测能进一步减小干扰,亦便于实现高通量检测。以DNA正四面体探针界面为代表的改良界面具有优良的灵敏度和特异性。同时本文亦讨论了现有方法的局限性,并对SNP非测序检测研究进行展望。     

A 2D cadmium metal–organic framework: Synthesis,structure and luminescence sensing for chromate,permanganate, cupric,silver and ferric

A multi-responsive Cd metal–organic framework {[Cd (ttpe)(H₂O)(ip)]•4H₂O•DMAC}_n ( 1•4H ₂ O•DMAC ) was synthesized using hydrothermal method (ttpe = 1,1,2,2-tetra(4-(1H-1,2,4-triazol-1-yl)phenyl)ethylene, ip = isophthalate, DMAC = N,N-dimethylacetamide), and characterized. 1 exhibits a 2D (4,4) network. The luminescent sensing experimrnts showed that 1•4H ₂ O•DMAC as a new MOF luminescent sensor can detect Cr₂O₇²⁻, CrO₄²⁻, MnO₄⁻, Cu²⁺, Ag⁺ and Fe³⁺ in aqueous solution with simultaneously high efficiency and high sensitivity. The quenching constants K_sv for Cr₂O₇²⁻, CrO₄²⁻, MnO₄⁻, Cu²⁺, Ag⁺ and Fe³⁺ are 4.231 × 10⁴ M⁻¹, 2.471 × 10⁴ M⁻¹, 6.459 × 10³ M⁻¹, 7.617 × 10³ M⁻¹, 1.563 × 10⁴ M⁻¹ and 3.574 × 10⁴ M⁻¹, respectively. The detection limits are 0.094 μM for Cr₂O₇²⁻, 0.108 μM for CrO₄^{2 −} , 0.346 μM for MnO₄⁻, 0.302 μM for Cu²⁺, 0.221 μM for Ag ⁺ , and 0.100 μM for Fe³⁺. 1•4H ₂ O•DMAC exhibits high photocatalytic efficiency for degradation of methylene blue under visible light irradiation.     

Surface-enhanced Raman scattering for protein detection

Proteins are essential components of organisms and they participate in every process within cells. The key characteristic of proteins that allows their diverse functions is their ability to bind other molecules specifically and tightly. With the development of proteomics, exploring high-efficiency detection methods for large-scale proteins is increasingly important. In recent years, rapid development of surface-enhanced Raman scattering (SERS)-based biosensors leads to the SERS realm of applications from chemical analysis to nanostructure characterization and biomedical applications. For proteins, early studies focused on investigating SERS spectra of individual proteins, and the successful design of nanoparticle probes has promoted great progress of SERS-based immunoassays. In this review we outline the development of SERS-based methods for proteins with particular focus on our proposed protein-mediated SERS-active substrates and their applications in label-free and Raman dye-labeled protein detection. Figure Protein-mediated SERS-active substrates for protein detection     

Amperometric multidetection with composite enzyme electrodes

The use of composite biosensors for multianalyte detection strategies is discussed. Graphite–Teflon rigid composite biosensors offer the possibility of coimmobilization of several enzymes by simple physical inclusion in the bulk of the electrode matrix with no covalent linkages. A novel trienzyme graphite–Teflon–glucose oxidase (GOD)–alcohol oxidase (AOD)–peroxidase (HRP)–ferrocene bisosensor yielded amperometric steady-state currents similar to those obtained with graphite–Teflon–GOD–HRP–ferrocene and graphite–Teflon–AOD–HRP–ferrocene electrodes for the same concentration of glucose and ethanol, respectively. The performance of the trienzyme biosensor for multianalyte detection was evaluated with the simultaneous determination of glucose and ethanol after separation by HPLC, in samples of sweet wine. The simultaneous analysis of several analytes in the same sample should imply that, with an adequate dilution, the concentration levels of the analytes can be included within the ranges of linearity of the corresponding calibration plots. The use of two composite biosensors in a parallel configuration, so that different analytes can be simultaneously detected with no need of chromatographic separation, is also discussed. The usefulness of this approach was evaluated by the simultaneous analysis of glucose and ethanol in sweet wine, and of glucose and lactic acid in red wine.     

Integration of Separation Capillary with a Au Film Electrode and an Etched Decoupler in Amperometric Capillary Electrophoresis

Introduced in this article is fabrication of an integrated capillary for the applications of electrochemical detection in capillary electrophoresis. The separation section, voltage decoupler, and working electrode were composed into a single section of capillary. The porous decoupler was constructed by HF etching till the thickness of the capillary wall less than 20 μm. The working electrode was prepared by sputtering Au-films on the outlet of the capillary. The integration of the separation capillary with a complete detection assembly improves the convenience for the routine application of electrochemical measurements in capillary electrophoresis. For a 100-μm-i.d. capillary, the theoretical plate number of catechol and the migration time reproducibility can reach 120,000 and 1.9% RSD, respectively. The linear range exceeds 3 order of magnitude and the detection limit is lower than 0.65 μM.     

光照度探测器设计与精度校正

助航灯光系统为夜间或能见度较低环境下飞机的安全起降提供安全保障。快速准确地测量和判断其光强等级、光照射角等是否符合国际民用航空组织(ICAO)的标准,是保障机场安全运行的重要工作。本文设计了基于硅光电池的照度探测器,通过余弦校正器和不同滤光片的组合完成视见函数校正和照度探测的精度标定,实现了灯光的高速动态检测;完成了光照度探测器的线性标定和动态精度测量实验,照度测量误差率和动态测量误差均满足ICAO规定的要求;实现了助航灯光平行截面内光强的高速动态检测。     

Chromenone-rhodamine conjugate for naked eye detection of Al3+ and Hg2+ ions in semi aqueous medium

Chromenone-rhodamine conjugate 1 has been synthesized and its metal ion binding properties have been studied in CH₃CN/water (3:1, v/v; 10 mM HEPES buffer; pH = 6.85). Compound 1 senses multiple metal ions such as Al³⁺ and Hg²⁺ by exhibiting turn on fluorescence and color change (colorless to pink). Al³⁺ and Hg²⁺ ions have been distinguished with the aid of tetrabutylammonium iodide (TBAI). While in the presence of I^? the pink color of the 1.Hg²⁺ complex was completely discharged; under identical conditions the pink color of 1.Al³⁺ complex was retained.     

A review of reaction detection in HPLC

Summary In the past decade, reaction detection has rapidly gained importance as a means to improve the sensitivity and selectivity of detection in HPLC. Today, most attention is being paid to post-column reaction detection with final analysis via fluorescence monitoring. Novel developments involve the use of solid-phase reactors for reagent addition or catalysis (ion-exchange resins, immobilized enzymes), and the increasing use of systems based on peroxyoxalate chemiluminescence detection. The rapidly growing number of reported applications indicates that commercialization of reaction-detection equipment is urgently needed.