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”)