Ericson Christer, Phung Qui T, Horn David M, Peters Eric C, Fitchett Jonathan R, Ficarro Scott B, Salomon Arthur R, Brill Laurence M, Brock Ansgar
Genomics Institute of the Novartis Research Foundation, 10675 John Jay Hopkins Drive, San Diego, California 92121, USA.
Anal Chem. 2003 May 15;75(10):2309-15. doi: 10.1021/ac026409j.
A new multichannel deposition system was developed for off-line liquid chromatography/matrix-assisted laser desorption/ionization mass spectrometry (LC/MALDI-MS). This system employs a pulsed electric field to transfer the eluents from multiple parallel columns directly onto MALDI targets without the column outlets touching the target surface. The deposition device performs well with a wide variety of solvents that have different viscosities, vapor pressures, polarities, and ionic strengths. Surface-modified targets were used to facilitate concentration and precise positioning of samples, allowing for efficient automation of high-throughput MALDI analysis. The operational properties of this system allow the user to prepare samples using MALDI matrixes whose properties range from hydrophilic to hydrophobic. The latter, exemplified by alpha-cyano-4-hydroxycinnamic acid, were typically processed with a multistep deposition method consisting of precoating of individual spots on the target plate, sample deposition, and sample recrystallization steps. Using this method, 50 amol of angiotensin II was detected reproducibly with high signal-to-noise ratio after LC separation. Experimental results show that there is no significant decrease in chromatographic resolution using this device. To assess the behavior of the apparatus for complex mixtures, 5 microg of a tryptic digest of the cytosolic proteins of yeast was analyzed by LC/MALDI-MS and more than 13,500 unique analytes were detected in a single LC/MS analysis.
开发了一种用于离线液相色谱/基质辅助激光解吸/电离质谱（LC/MALDI-MS）的新型多通道沉积系统。该系统采用脉冲电场将多个平行柱中的洗脱液直接转移到MALDI靶上，而柱出口不接触靶表面。该沉积装置对具有不同粘度、蒸气压、极性和离子强度的多种溶剂都能良好运行。使用表面改性靶有助于样品的浓缩和精确定位，从而实现高通量MALDI分析的高效自动化。该系统的操作特性允许用户使用性质从亲水性到疏水性的MALDI基质来制备样品。后者以α-氰基-4-羟基肉桂酸为例，通常采用多步沉积方法进行处理，该方法包括在靶板上预涂各个斑点、样品沉积和样品重结晶步骤。使用该方法，在LC分离后，可重复检测到50 amol的血管紧张素II，信噪比很高。实验结果表明，使用该装置时色谱分辨率没有显著降低。为了评估该仪器对复杂混合物的性能，通过LC/MALDI-MS分析了5 μg酵母胞质蛋白的胰蛋白酶消化物，在一次LC/MS分析中检测到了超过13500种独特的分析物。
