eem_coble_peaks: Extract fluorescence peaks
In eemR: Tools for Pre-Processing Emission-Excitation-Matrix (EEM) Fluorescence Data

Description Usage Arguments Details Value Interpolation References See Also Examples

Extract fluorescence peaks

1	eem_coble_peaks(eem, verbose = TRUE)

`eem`	An object of class `eemlist`.
`verbose`	Logical determining if additional messages should be printed.

According to Coble (1996), peaks are defined as follow:

Peak B: ex = 275 nm, em = 310 nm

Peak T: ex = 275 nm, em = 340 nm

Peak A: ex = 260 nm, em = 380:460 nm

Peak M: ex = 312 nm, em = 380:420 nm

peak C: ex = 350 nm, em = 420:480 nm

Given that peaks A, M and C are not defined at fix emission wavelength, the maximum fluorescence value in the region is extracted.

An object of class eemlist.

A data frame containing peaks B, T, A, M and C for each eem. See details for more information.

Different excitation and emission wavelengths are often used to measure EEMs. Hence, it is possible to have mismatchs between measured wavelengths and wavelengths used to calculate specific metrics. In these circumstances, EEMs are interpolated using the interp2 function from the parcma library. A message warning the user will be prompted if data interpolation is performed.

Coble, P. G. (1996). Characterization of marine and terrestrial DOM in seawater using excitation-emission matrix spectroscopy. Marine Chemistry, 51(4), 325-346.

http://doi.org/10.1016/0304-4203(95)00062-3

interp2

file <- system.file("extdata/cary/scans_day_1/", "sample1.csv", package = "eemR")
eem <- eem_read(file, import_function = "cary")

eem_coble_peaks(eem)