Rapid analysis of metal ions and organic compounds in strong acidic solutions is of sustainable interest in multiple disciplines. However, complicated and time-consuming pretreatments are always required for MS analysis of the compounds in strong acidic solutions. Otherwise, it will result in a weak signal and cause serious damage to the mass spectrometer. Herein, a simple method inherited from nano-ESI MS was developed for rapid analysis of strong acidic solutions. Nanoliter (nL) strong acidic solution was first loaded in the nano-ESI emitter, followed by evaporation to remove the H+ and leave the analytes on the wall of the nano-ESI emitter. The evaporation process can be completed within 1 min because of the extremely tiny volume (≤1 nL) of the loaded solution. Then, the dried analytes on the wall of the nano-ESI emitter were redissolved by loading a new solvent, followed by nano-ESI MS analysis. By using this method, metal ions and organic compounds in the strong acidic solution can be detected with low sample consumption (1 nL), high speed (< 2 min/sample), high sensitivity (limit of detection = 0.2 µg/L), and high accuracy (> 90%). Proof-of-concept applications of the present method have been successfully achieved for the analysis of gastric juice (pH of the sample = 1), monitoring reaction catalyzed by strong acid (pH of the system = 0), and micro-area analysis of ores (pH of the extraction solvent = 0), showing great application potential in multiple fields.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |