Hattan Stephen J, Vestal Marvin L
Virgin Instruments Corporation, 60 Union Avenue (Suite l-R), Sudbury, Massachusetts 01776, USA.
Anal Chem. 2008 Dec 1;80(23):9115-23. doi: 10.1021/ac8017108.
Novel matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) sample plates employing collimated-hole structures have been developed that allow capture and concentration of samples while simultaneously acting as a sink for carrier solvents. These plates were designed to provide an efficient interface between higher-capacity liquid chromatography (LC) separations and MALDI-TOF mass spectrometry (MS). LC-MALDI using conventional plates can accommodate the low-flow (< 1 microL/min) separation protocols typically used in on-line LC-MS methods, and can also be used with higher flow rate, larger columns, but are ultimately limited by the capacity of the two-dimensional surface onto which the sample is deposited. Typically, about 1 microL of chromatographic effluent plus 1 microL of matrix solution can be deposited and dried on a ca. 3 mm diameter spot. Deposition rates (spot dwell time) are determined by the chromatographic resolution and the flow rate. To overcome this limitation, a new three-dimensional MALDI sample plate has been developed using collimated-hole structures (CHS) with monolithic chromatography media filling the holes in the collimated-hole structures. These new plates retain all of the required features of conventional sample plates, commonly formed from stainless steel, but provide additional capacity for capturing and concentrating samples. Results are presented from reversed-phase separation of peptides on a 1 mm i.d. column operating at flow rate of 50 microL/min. Typically, 10 microL of effluent can be collected on a single spot, and sample and matrix dried on a 1 mm diameter spot, to yield about 30-fold enrichment of sample concentration in matrix crystals on the surface compared to the conventional plate. Sample loadings ranging from 1 fmol to 10 pmol/spot were investigated.
已开发出采用准直孔结构的新型基质辅助激光解吸电离飞行时间（MALDI-TOF）样品板，该样品板可捕获和浓缩样品，同时作为载液的汇集器。这些样品板旨在为高容量液相色谱（LC）分离与MALDI-TOF质谱（MS）之间提供高效接口。使用传统样品板的LC-MALDI可适应在线LC-MS方法中通常使用的低流速（<1微升/分钟）分离方案，也可与更高流速、更大的色谱柱一起使用，但最终会受到样品沉积二维表面容量的限制。通常，约1微升的色谱流出物加1微升的基质溶液可沉积并干燥在直径约3毫米的斑点上。沉积速率（斑点停留时间）由色谱分辨率和流速决定。为克服这一限制，已开发出一种新的三维MALDI样品板，其采用准直孔结构（CHS），并在准直孔结构的孔中填充了整体式色谱介质。这些新样品板保留了通常由不锈钢制成的传统样品板的所有必要特性，但提供了额外的捕获和浓缩样品的能力。给出了在内径1毫米的色谱柱上以50微升/分钟的流速进行肽反相分离的结果。通常，可在单个斑点上收集10微升流出物，并在直径1毫米的斑点上干燥样品和基质，与传统样品板相比，表面基质晶体中的样品浓度可富集约30倍。研究了每个斑点1飞摩尔至10皮摩尔的样品上样量。
