Objective: To develop a method for the analysis of phenylglyoxylic acid (PGA) and mandelic acid (MA) in urine by ultra-high performance liquid chromatography tandem mass spectrometry. Methods: The study was conducted in April 2022. Urine samples were directly diluted with the initial mobile phase, separated by Waters HSS T3 column after passing through the membrane, and analyzed under negative ionization mode (ESI(-)) and multiple reaction monitoring (MRM) conditions, the contents of PGA and MA in human urine were quantitatively determined by external standard method. Results: The determination of PGA and MA showed a good linear relationship within the range of 10-1000 ng/ml, with a correlation coefficient of 0.9999. The linear regression equation of PGA was y=1141.4x+2157.3, the detection limit and lower limit of quantification of the method were 0.081 ng/ml and 0.269 ng/ml, and the recovery rate was 90.47%-99.83%. The linear regression equation of MA was y=62.8x+140.3, the detection limit and lower limit of quantification of the method were 0.551 ng/ml and 1.836 ng/ml, and the recovery rate was 92.75%-101.09%. The intra and inter batch precision of PGA and MA were both<5%. Conclusion: An ultra-high performance liquid chromatography tandem mass spectrometry method for the analysis of PGA and MA in urine was established.The sample pretreatment operation is simple, and the accuracy and precision of the method meet the standard requirements. It can be used for monitoring and evaluating PGA and MA in urine of the general population and occupational contact population.
本研究构建了以城市污泥基氧化石墨烯(GO)为模拟酶的比色传感器用于定量检测H2O2.以城市污泥为基质利用改进Hummers法制备氧化石墨烯(GO),利用GO具有过氧化物模拟酶的特性,能够催化 H2O2与3,3',5,5'-四甲基联苯胺(TMB)的显色反应定量检测H2O2.结果显示,在最佳检测条件HAc-NaAc缓冲溶液pH 4.8、TMB溶液浓度30 mmol·L-1和城市污泥基GO浓度460 μg·mL-1时,H2O2浓度在0.1～2 μmol·L-1和10～150 μmol·L-1范围内,与体系吸光度呈良好的线性关系,最低检测限为0.01 μmol·L-1.此方法对实际水样中H2O2含量进行检测,回收率在99％～103.77％之间.研究表明,城市污泥基GO具有与传统GO一致的过氧化物酶催化特性,在传感检测领域具有一定的应用潜力,为比色传感检测H2O2提供了新的思路.
建立了以活性为导向的快速筛选分离及鉴定茯苓中活性成分的分析方法.以茯苓总三萜得率为评价指标,应用星点设计-效应面法选取茯苓石油醚提取的最佳条件为:1-丁基-3-甲基咪唑四氟硼酸盐([Bmim][BF4])浓度为0.4 mol/L,用量为10％,液料比为30:1,提取时间为35 min,提取次数为3次;利用超滤-质谱技术(UF-LC-MS)共筛选得到5个潜在的乙酰胆碱酯酶(AChE)抑制剂和3个潜在的5-脂氧合酶(5-LOX)抑制剂.以活性为导向,经高速逆流色谱(HSCCC)结合半制备高效液相色谱(Semi-preparative HPLC)技术联合分离,从200 mg茯苓提取物中,分离制备得到2.36 mg 3-表去氢土莫酸、3.54 mg去氢茯苓酸,8.57 mg茯苓酸、5.34 mg松苓新酸、4.32 mg 3-氢化松苓酸,经高效液相色谱(HPLC)分析其纯度均达到90.0％以上;并采用超高效液相色谱高分辨质谱仪及核磁共振波谱技术对单体活性成分进行鉴定.本研究所建立的方法简单、快速、高效,分离样品纯度高,适用于茯苓中三萜类活性化合物的分离纯化及鉴定研究,为天然药物的开发与应用提供了理论基础和技术支持.
上转换材料因其具有在不同光谱区域之间转换光的能力和特殊的光物理特性,克服了传统荧光材料的一些缺点,为高灵敏度的化学和生物传感器的构建提供了新思路,在分析检测领域引起了广泛关注.本文介绍了近年来利用上转换材料所构建的传感器,其中包含荧光共振能量转移型、辐射能量转移型和非能量转移型三类传感器及其应用于药物和生物活性分子分析测定的相关研究.同时,本文还对此类传感器的未来发展趋势进行了展望,其中上转换材料的制备尺寸以及传感器多功能设计的合理性及其生物稳定性是此类传感器未来发展的重要影响因素.
数字PCR作为一种新型核酸分析方法,能对样品中目标核酸分子进行绝对定量,具有极高的检测灵敏度和突出的抗背景序列对靶序列的竞争抑制能力.凭借这些优势,数字PCR在癌症标志物检测、无创产前检查等领域具有广阔的应用前景.液滴数字PCR技术将PCR反应体系稀释并分散至大量液滴中,使液滴成为最多只包含单核酸分子的独立反应单元后进行PCR扩增和检测.目前液滴数字PCR分析系统大多采用微流控芯片生成液滴,芯片结构复杂、加工困难、价格高昂,这些因素在一定程度上限制了其推广应用.探索能快速生成大规模液滴的方法对促进液滴数字PCR系统的发展具有重要意义.本文综述了微流控液滴生成技术和液滴数字PCR系统的研究进展,对膜乳化法、微流控芯片法和毛细管法进行了分类介绍并总结了它们的优缺点,介绍了微流控液滴数字PCR系统和商业化产品,并对液滴数字PCR技术的发展前景进行了展望.
