endPoint detection function
The data frame containing the background corrected remainder of the acquisition (Figure 2b) was supplied to the endPoint function. With the first 35 seconds removed, we ensured that the laser was pulsing on the foraminifera’s outer test wall and the ablated material was reaching the mass detector for the first row in the data frame supplied. In this example, we use the 44Ca isotope measurements due to the high signal: noise ratio and the abundance of 44Ca within the foraminifera test, which provides greater distinction between higher signal counts for the duration when the laser was on target and lower signal counts when the laser was ablating the glass slide mount. The endPoint function was used to dynamically identify the time step when the laser had fully ablated through the foraminifera test and to keep only the observations while the laser was ablating the target (Figure 2c).
endPoint(detectDf = foram72shot3, dt = 10, smoothing = 5, timeCol = ”Time”, signalCol = ”Ca44”, profile = ”TRUE”, timeUnits = ”seconds”)