The MALDI‐based mass spectrometry, over the last three decades, has become an important analytical tool. It is a gentle ionization technique, usually applicable to detect and characterize analytes with high molecular weights like proteins and other macromolecules. The earlier difficulty of detection of analytes with low molecular weights like small organic molecules and metal ion complexes with this technique arose due to the cluster of peaks in the low molecular weight region generated from the matrix. To detect such molecules and metal ion complexes, a four‐prong strategy has been developed. These include use of alternate matrix materials, employment of new surface materials that require no matrix, use of metabolites that directly absorb the laser light, and the laser‐absorbing label‐assisted LDI‐MS (popularly known as LALDI‐MS). This review will highlight the developments with all these strategies with a special emphasis on LALDI‐MS.

中文翻译：

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激光解吸电离质谱：无基质和标签辅助技术的最新进展

在过去的三十年中，基于MALDI的质谱已成为重要的分析工具。这是一种柔和的电离技术，通常适用于检测和表征高分子量的分析物，例如蛋白质和其他大分子。由于由基质产生的低分子量区域中的峰簇，使用这种技术检测低分子量分析物（如有机小分子和金属离子络合物）的早期难度更大。为了检测此类分子和金属离子络合物，已开发了一种四叉策略。这些措施包括使用替代基质材料，使用不需要基质的新表面材料，使用直接吸收激光的代谢物以及激光吸收标签辅助的LDI-MS（通常称为LALDI-MS）。