Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA.
Anal Chem. 2010 Apr 1;82(7):2753-8. doi: 10.1021/ac9026466.
A novel atmospheric pressure imaging mass spectrometry approach that offers improved lateral resolution (10 microm) using near-infrared femtosecond laser pulses for nonresonant desorption and ionization of sample constituents without the need of a laser-absorbing matrix is demonstrated. As a proof of concept the method was used to image a two-chemical pattern in paper. To demonstrate the ability of the approach to analyze biological tissue, a monolayer of onion epidermis was imaged allowing the chemical visualization of individual cells using mass spectrometry at ambient conditions for the first time. As the spatial resolution is currently limited by the limit of detection of the setup (approximately 500 fmol limit of detection for citric acid), improvements in sensitivity will increase the achievable spatial resolution.
我们展示了一种新颖的常压成像质谱方法，该方法使用近红外飞秒激光脉冲进行非共振解吸和离子化，无需激光吸收基质，从而提高了横向分辨率（10 微米）。作为概念验证，该方法用于对纸张上的两种化学模式进行成像。为了证明该方法分析生物组织的能力，我们对单层洋葱表皮进行了成像，首次在环境条件下使用质谱法对单个细胞进行化学可视化。由于目前空间分辨率受到设置检测限的限制（柠檬酸的检测限约为 500 fmol），因此提高灵敏度将提高可实现的空间分辨率。
