DNA purification using dynamic solid-phase extraction on a rotationally-driven polyethylene-terephthalate microdevice

We report the development of a disposable polyester toner centrifugal device for semi-automated, dynamic solid phase DNA extraction (dSPE) from whole blood samples. The integration of a novel adhesive and hydrophobic valving with a simple and low cost microfabrication method allowed for sequential addition of reagents without the need for external equipment for fluid flow control. The spin-dSPE method yielded an average extraction efficiency of ∼45% from 0.6 μL of whole blood. The device performed single sample extractions or accommodate up to four samples for simultaneous DNA extraction, with PCR-readiness DNA confirmed by effective amplification of a β-globin gene. The purity of the DNA was challenged by a multiplex amplification with 16 targeted amplification sites. Successful multiplexed amplification could routinely be obtained using the purified DNA collected post an on-chip extraction, with the results comparable to those obtained with commercial DNA extraction methods. This proof-of-principle work represents a significant step towards a fully-automated low cost DNA extraction device.     

分散固相萃取-超快速液相色谱-串联质谱法测定牛蛙全血中6种酚类环境雌激素

建立了一种快速、灵敏、准确的同时测定牛蛙全血中双酚A、己烯雌酚、己二烯雌酚、己烷雌酚、4-叔辛基酚和4-壬基酚等6种酚类环境雌激素的分散固相萃取-超快速液相色谱-串联质谱(dSPE-UFLC-MS/MS)分析方法。牛蛙全血样品经含0.1%(v/v)甲酸的甲醇溶液沉淀蛋白后,利用自制的氨基功能化Fe3O4磁性高分子复合微粒(EDA-MPs)作为dSPE吸附剂进行净化,着重考察了沉淀剂、吸附净化时间、吸附剂用量等因素对6种酚类环境雌激素回收率的影响。采用Shim-pack XR-ODSII(100 mm×2.0 mm, 2.2 μm)反相液相色谱柱进行分离,在电喷雾离子源(ESI)负离子多反应监测(MRM)模式下进行检测。结果表明: 6种酚类环境雌激素在0.5～100.0 μg/L范围内具有良好的线性关系(r2≥0.9996),方法的定量限(信噪比大于10)为0.075～0.40 μg/L,方法的精密度为0.6%～6.3%,空白样品中3个不同水平的添加回收率为95.0%～110.0%。本方法适用于牛蛙全血中6种酚类环境雌激素的同时测定。     

水产品中11种海洋生物毒素的高效液相色谱-四极杆/静电场轨道阱高分辨质谱检测方法研究

建立了水产品中11种海洋生物毒素的高效液相色谱-四极杆/静电场轨道阱高分辨质谱(HPLC-Q-Orbitrap HRMS)检测方法。该方法采用分级提取原理,结合分散固相萃取技术(dSPE)和载体辅助液液萃取技术(SLLE),建立了对亲水性及亲脂性海洋生物毒素的"一站式"提取净化体系。在优化条件下,11种毒素在一定质量浓度范围内具有良好的线性关系,相关系数(r)均大于0.99。该方法对11种毒素的检出限为1～10μg/kg,定量下限为2～20μg/kg,加标回收率为55.6%～122%,相对标准偏差为5.4%～16%。方法快速高效,可操作性强,解决了不同理化性质的海洋生物毒素的通用性检测问题,可满足水产品中海洋生物毒素的快速筛查要求。     

分散固相萃取-超高效液相色谱-串联质谱法测定水产品中5种硝基咪唑类和6种苯二氮卓类药物北大核心CSCD

建立了分散固相萃取-超高效液相色谱-串联质谱法同时测定水产品中5种硝基咪唑类和6种苯二氮卓类药物残留的方法。样品用1%(v/v)氨水乙腈提取,提取液经十八烷基键合硅胶(C18)和N-丙基乙二胺(PSA)吸附剂净化,在45℃下用氮气吹至近干,用1 mL甲醇-水(1∶9,v/v)溶液复溶,过0.22μm尼龙-66滤膜后用超高效液相色谱-串联质谱测定。目标化合物采用Kinetex F5色谱柱(100 mm×3.0 mm,2.6μm)分离,以0.1%(v/v)甲酸水溶液和甲醇作为流动相进行梯度洗脱,在电喷雾离子源(ESI)、正离子扫描和多反应监测(MRM)模式下进行测定,基质匹配外标法定量。结果表明,5种硝基咪唑类和6种苯二氮卓类药物在8.5 min内完成色谱分离分析,目标物在0.5~20μg/L范围内线性关系良好,相关系数均大于0.995,检出限和定量限分别为0.2~0.5μg/kg和0.5~1.0μg/kg。以草鱼、对虾和大黄鱼为样品基质,在3个不同的添加水平下,5种硝基咪唑类和6种苯二氮卓类药物的平均回收率为73.2%~110.6%,相对标准偏差(RSD)小于15%。本研究建立的方法具有简单、快速、灵敏度高和成本低等优势,可用于水产品中5种硝基咪唑类和6种苯二氮卓类药物的快速检测。该方法的建立为我国水产品质量安全相关监管部门同时监控水产品中硝基咪唑类和苯二氮卓类药物残留提供了技术支持。     

Multi-analyte high performance liquid chromatography coupled to high resolution tandem mass spectrometry method for control of pesticide residues,mycotoxins, and pyrrolizidine alkaloids

A new reliable and highly sensitive method based on high performance liquid chromatographic (HPLC) separation and high resolution tandem mass spectrometric detection (HRMS/MS) has been developed and validated for determination of 323 pesticide residues, 55 mycotoxins, and 11 plant toxins represented by pyrrolizidine alkaloids. The method was validated for three matrices, leek, wheat, and tea differing in nature/amount of co-extracts that may cause various matrix effects. For target analytes isolation, optimized QuEChERS-based (quick, easy, cheap, effective, rugged, and safe) extraction procedure was employed. Spectral HRMS/MS library has been established providing an entire spectrum of fragment ions for each analyte, which allows unbiased identification and confirmation of target compounds. The limits of quantification (LOQs) of target analytes were below 10 μg kg⁻¹ for 82%, 81%, and 61% for matrices leek, wheat, and tea, respectively. Recoveries were in the acceptable range (70–120%) according to SANCO/12571/2013 for most of target analytes, except for highly polar ‘masked’ mycotoxin deoxynivalenol-3-glucoside with recoveries 35%, 47%, and 42% for matrices leek, wheat, and tea, respectively. The linearities of calibration curves expressed as coefficients of determination were in the range of 0.9661–1.000, and repeatabilities expressed as relative standard deviations (RSDs) at LOQs lied in the range of 0.25–13.51%. The trueness of the method was verified using several certified reference materials (CRMs) and proficiency test samples.     

气相色谱-质谱法检测豆制品中的二甲基黄

建立气相色谱–质谱法测定豆制品中二甲基黄的方法。考察了不同样品前处理方法对回收率的影响。试样用d SPE纯化管超声净化后,以10 mL乙腈提取。样品溶液经毛细管气相色谱柱HP–5MS分离,以质谱检测器(MSD)测定其中的二甲基黄含量。二甲基黄的质量浓度在0.05~1.5 ng/mL范围内与响应值呈良好的线性关系,相关系数r=0.999 1,检出限为0.005 mg/kg。加标水平为0.005~1.0 mg/kg时的平均回收率为70%~88%,测定结果的相对标准偏差为2.5%~8.0%(n=6)。该方法净化效果好,灵敏度高,适合于豆制品中二甲基黄的检测。     

分散固相萃取/液相色谱-串联质谱法测定茶叶中草甘膦及其代谢物氨甲基膦酸的残留量

建立了一种分散固相萃取结合高效液相色谱-串联质谱法测定茶叶样品中草甘膦(PMG)及其代谢物氨甲基膦酸(AMPA)残留量的分析方法。样品经0.2%甲酸水超声提取,层状氢氧化镁铝水滑石(Mg-AlLDHs)吸附富集,碳酸钠溶液洗脱后,以9-芴基氯甲酸酯(FMOC-Cl)为衍生剂衍生2 h,Kinetex C18柱(50mm×2.1 mm,2.6μm,Phenomenex)分离,以乙腈-5 mmol/L乙酸铵水溶液(含0.2%甲酸)为流动相梯度洗脱,电喷雾正离子模式电离(ESI+),多反应监测(MRM)模式检测,同位素内标法定量。草甘膦及其代谢物氨甲基膦酸在10~1 000 ng/m L范围内具有良好线性,相关系数均大于0.999,检出限和定量下限分别为0.015 mg/kg和0.05 mg/kg;在不同基质中,0.05,0.1,1.0 mg/kg 3个加标水平的平均回收率为86.6%~95.7%,相对标准偏差为5.1%~12.2%。该方法具有简便、快速、灵敏度高、准确性强等特点,可用于茶叶中草甘膦及其代谢物氨甲基膦酸残留的快速检测。     

基质分散固相萃取-液相色谱-串联质谱法检测动物源性食品中硝基咪唑药物及其代谢物

建立了基质分散固相萃取-液相色谱-串联质谱（dSPE-LC-MS/MS）定量检测4种动物源性食品基质中硝基咪唑类药物及其代谢物的方法。样品（2.0 g）用乙酸乙酯提取后浓缩,经正己烷脱脂、50 mg乙二胺-N-丙基硅烷（PSA）吸附剂吸附净化后,过0.22 μm亲水聚四氟乙烯（PTFE）滤膜。采用C18柱分离,在电喷雾电离（ESI）源和选择反应监测（SRM）模式下检测,基质匹配内标法定量。在0.5~20.0 μg/L范围内,硝基咪唑类药物及其代谢物呈现良好的线性关系,相关系数（r²）>0.99;方法的检出限为0.1~0.5 μg/kg;在1.0、3.0和10.0 μg/kg的加标水平下,硝基咪唑类药物及其代谢物的回收率为84.2%~120.8%,相对标准偏差为2.0%~16.2%（n=6）。该法准确、快速,成本低,易操作,能够满足动物源性食品中硝基咪唑类药物及其代谢物残留的监测要求。     

Dispersive solid-phase extraction clean up combined with Soxhlet extraction for the determination of 16 PAHs in soil samples by GC-MS

Dichloromethane soil samples extracts were prepared using Soxhlet extraction technique, and after clean-up step, gas chromatography-mass spectrometry analysis of 16 priority polycyclic aromatic hydrocarbons (PAHs) was carried out. A comparison of dispersive solid-phase extraction (dSPE) and column chromatography (cC), as clean-up techniques, was evaluated. Six different sorbents (silica, diatomaceous earth, primary–secondary amine, C18, clinoptilolite and florisil) were tested as dispersive clean-up sorbents versus activated silica and alumina for cC. Best results for three concentration levels among dSPE were obtained using diatomaceous earth, with recovery values in the range of 75–112% for 13 of 16 analysed compounds, while cC recoveries were in the range of 75–111% for all analysed PAHs. Analysis of 12 soil samples from urban area of Ni? (Serbia) singled out acenaphthene as the most abundant compound.     

SiW11掺杂二氧化硅纳米纤维(SiW11/SiO2)的制备及对拟南芥叶中多胺的萃取分析

采用静电纺丝技术制备了SiW₁₁掺杂的二氧化硅纳米纤维(SiW₁₁/SiO₂)材料, 其中掺杂的SiW₁₁质量占纤维质量的7.83%, 制备的SiW₁₁/SiO₂材料尺寸均一, 在考察的pH范围内带负电, 与未掺杂SiW₁₁的二氧化硅纳米纤维相比, SiW₁₁/SiO₂材料表现出强阳离子交换作用, 能有效萃取尸胺和腐胺. 在最优条件下, 建立了注射器分散固相萃取(In syringe dSPE)-超高效液相色谱-串联质谱联用(UHPLC-MS/MS)检测拟南芥样品中多胺的方法. 结果表明, 尸胺和腐胺分别在10~1000和20~1000 ng/mL浓度范围内具有良好的线性关系(R²≥0.9950), 检出限和定量限分别为0.5~0.9和1.6~3.0 ng/mL. 将该方法应用于拟南芥样品中尸胺和腐胺的检测, 加标回收率在87.5%~111.3%之间, 相对标准偏差RSD<5.0%. 建立的SiW₁₁/SiO₂制备方法解决了多金属氧酸盐(POM)在修饰改性过程中存在的制备繁琐、 固载量少的问题, 拓宽了POM在分离领域中的应用.