Shariatgorji Mohammadreza, Amini Nahid, Thorsen Gunnar, Crescenzi Carlo, Ilag Leopold L
Department of Analytical Chemistry, Stockholm University, 106 91 Stockholm, Sweden.
Anal Chem. 2008 Jul 15;80(14):5515-23. doi: 10.1021/ac8005186. Epub 2008 May 31.
A procedure for rapidly screening and quantitatively analyzing organic molecules is presented, in which a miniaturized solid-phase extraction (SPE) cartridge containing 0.6 mg of graphitized carbon black (the GCB-mu-trap) is used for sample pretreatment. Then surface-assisted laser desorption ionization time-of-flight mass spectrometry (SALDI-TOF-MS) screening is followed by liquid chromatography/mass spectrometry (LC/MS) for robust quantitative analysis of samples containing analytes of interest. Liquid samples with volumes up to 100 mL were extracted using the GCB-mu-trap, and SALDI screening was performed by transferring a few particles of the GCB 4 sorbent from the mu-trap onto a stainless steel plate. Analytes were then simply ionized and desorbed by irradiating the GCB 4 particles without any further pretreatment. GCB 4 was found to be an excellent surface for the SALDI analysis of small molecules, providing spectra with very clean backgrounds. The small size of the cartridge (micropipet filter tip) results in enrichment of the analytes on a small surface area, affording low SALDI-TOF-MS detection limits. Furthermore, the removal of just a few particles from the mu-trap does not significantly affect the subsequent quantitative determination. This approach offers considerable reductions in analytical costs by eliminating unnecessary SPE-LC/MS analyses.
本文介绍了一种快速筛选和定量分析有机分子的方法，该方法使用含有0.6毫克石墨化炭黑的小型化固相萃取（SPE）柱（GCB-μ阱）进行样品预处理。然后进行表面辅助激光解吸电离飞行时间质谱（SALDI-TOF-MS）筛选，接着采用液相色谱/质谱（LC/MS）对含有目标分析物的样品进行可靠的定量分析。使用GCB-μ阱萃取体积达100 mL的液体样品，通过将μ阱中的少量GCB 4吸附剂颗粒转移到不锈钢板上来进行SALDI筛选。然后，无需任何进一步预处理，只需照射GCB 4颗粒即可使分析物简单地离子化和解吸。发现GCB 4是小分子SALDI分析的优良表面，可提供背景非常干净的光谱。柱（微量移液器滤头）的小尺寸导致分析物在小表面积上富集，从而实现低SALDI-TOF-MS检测限。此外，从μ阱中取出少量颗粒不会显著影响后续的定量测定。这种方法通过消除不必要的SPE-LC/MS分析，大幅降低了分析成本。
