Kirby Andrea E, Lafrenière Nelson M, Seale Brendon, Hendricks Paul I, Cooks R Graham, Wheeler Aaron R
Department of Chemistry, University of Toronto , 80 St George Street, Toronto, Ontario M5S 3H6, Canada.
Anal Chem. 2014 Jun 17;86(12):6121-9. doi: 10.1021/ac5012969. Epub 2014 Jun 6.
We report the development of a method coupling microfluidics and a miniature mass spectrometer, applied to quantitation of drugs of abuse in urine. A custom digital microfluidic system was designed to deliver droplets of solvent to dried urine samples and then transport extracted analytes to an array of nanoelectrospray emitters for analysis. Tandem mass spectrometry (MS/MS) detection was performed using a fully autonomous 25 kg instrument. Using the new method, cocaine, benzoylecgonine, and codeine can be quantified from four samples in less than 15 min from (dried) sample to analysis. The figures of merit for the new method suggest that it is suitable for on-site screening; for example, the limit of quantitation (LOQ) for cocaine is 40 ng/mL, which is compatible with the performance criteria for laboratory analyses established by the United Nations Office on Drugs and Crime. More importantly, the LOQ of the new method is superior to the 300 ng/mL cutoff values used by the only other portable analysis systems we are aware of (relying on immunoassays). This work serves as a proof-of-concept for integration of microfluidics with miniature mass spectrometry. The system is attractive for the quantitation of drugs of abuse from urine and, more generally, may be useful for a wide range of applications that would benefit from portable, quantitative, on-site analysis.
我们报告了一种将微流控技术与微型质谱仪相结合的方法的开发，该方法应用于尿液中滥用药物的定量分析。设计了一种定制的数字微流控系统，用于将溶剂滴输送到干燥的尿液样本中，然后将提取的分析物输送到纳米电喷雾发射器阵列进行分析。使用一台25千克的全自动仪器进行串联质谱（MS/MS）检测。使用这种新方法，从（干燥的）样本到分析，可在不到15分钟内对四个样本中的可卡因、苯甲酰爱康宁和可待因进行定量。新方法的性能指标表明它适用于现场筛查；例如，可卡因的定量限（LOQ）为40 ng/mL，这与联合国毒品和犯罪问题办公室制定的实验室分析性能标准相符。更重要的是，新方法的LOQ优于我们所知的唯一其他便携式分析系统（依靠免疫测定）所使用的300 ng/mL的临界值。这项工作为微流控技术与微型质谱仪的集成提供了概念验证。该系统对于尿液中滥用药物的定量分析具有吸引力，更广泛地说，对于许多受益于便携式、定量、现场分析的应用可能是有用的。
