Research Center for Analytical Sciences, Department of Chemistry, College of Sciences, Northeastern University, Shenyang 110819, China.
Anal Chem. 2022 Jun 14;94(23):8547-8553. doi: 10.1021/acs.analchem.2c01736. Epub 2022 Jun 2.
Laser ablation inductively coupled plasma mass spectrometry imaging of biologically significant targets largely relies on maintaining the original structures of samples. The temperature regulation capability of the ablation cell is crucial. Herein, a rapid cooling cryogenic sample cell (RCCSC) was developed. In the RCCSC chamber, the temperature reduces to -20 °C in 4 min with a minimum 10 h variation of ±0.1 °C at -26 °C. Improvements on the precision were achieved for the elements of interest in NIST 612 and spiked agarose gel under cryogenic conditions. The limits of detection improved by up to 1.57, 1.70, 3.26, and 1.33 fold for Cu, Zn, Fe, and Ce in agarose gel, respectively, were obtained under cryogenic conditions compared with those at room temperature. In a time period of testing (10 h), the cryogenic ablation maintains the native state of biological tissues with a high water content to ensure better elemental imaging by reducing thermal effects in ablation and suppressing evaporation of water. The rapid cooling cryogenic ablation significantly improves elemental imaging, as demonstrated by the imaging of various elements in coriander leaves. The present study may provide further insights into elemental distributions in fresh biological samples.
激光烧蚀电感耦合等离子体质谱成像技术主要依赖于保持样品的原始结构，而烧蚀池的温度调节能力至关重要。本研究开发了一种快速冷却低温样品池（RCCSC）。在 RCCSC 腔室内，温度在 4 分钟内降至-20°C，在-26°C 时最小 10 小时的变化为±0.1°C。在低温条件下，对 NIST 612 和琼脂糖凝胶中感兴趣的元素的精度进行了改进。与室温相比，在琼脂糖凝胶中，Cu、Zn、Fe 和 Ce 的检测限分别提高了 1.57、1.70、3.26 和 1.33 倍。在测试时间段（10 小时）内，低温烧蚀通过减少烧蚀中的热效应和抑制水的蒸发，保持高含水量的生物组织的天然状态，从而确保更好的元素成像。快速冷却低温烧蚀显著改善了元素成像，如通过香菜叶片中各种元素的成像所证明的。本研究可能为新鲜生物样品中元素分布提供进一步的见解。
