Abstract:
BACKGROUNDIn recent years, laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS) for quantitative analysis of single fluid inclusion components has become one of the best methods for studying fluid inclusions. Due to the low success rate of this experiment, it is of great help to improve the experimental success rate by standardizing the whole experimental procedure and correctly processing the experimental data. At this stage, the data analysis software used at home and abroad is a SILLS software based on MATLAB, which deals with the LA-ICP-MS analysis results of mineral (zircon, etc.), fluid inclusions and melt inclusion.
OBJECTIVESTo help researchers properly operate the entire experimental process, and to detail the use of the SILLS software for improved LA-ICP-MS analysis of single fluid inclusion.
METHODSThe fluorite fluid inclusions were analyzed by LA-ICP-MS at the James Cook University, and the data was processed using the SILLS software. The actual operation of the experiment was performed to discuss common problems during the experiment.
RESULTSThe fluorite fluid inclusion LA-ICP-MS analysis was taken as an example to standardize the sample preparation and selection before the experiment. The instrument parameters were set in the experiment, the internal and external standard samples were selected, and the Straight Ablation method was used instead of the Stepwise Ablation method. At the same time, based on the SILLS software, the peak elimination and how to choose a reasonable peak width in different situations were explained. In the element ratio correction and the equivalent salinity calculation, since the sample to be tested was fluorite, the Ca element had a higher background value. Therefore, the host mineral concentration was calculated by using Na as the internal standard element of the fluid inclusion and Ca as the internal standard element of the host mineral. At the same time, it was proposed to calculate the equivalent salinity by replacing the mass balance with the charge balance.
CONCLUSIONSThe above scheme improves the accuracy of LA-ICP-MS analysis of individual fluorite fluid inclusions and helps to more accurately explain the source of ore-forming fluids and the genesis of the deposit.