I'd like to start a discussion of analyzing for boron using EPMA.
Of course, much of what we know from characterization of other light elements (O, N, C) also applies to boron, though usually without the contamination or native oxide issues! On the other hand, the absorption corrections for boron Ka are enormous, with absorption coefficients often as large as 10^5 cm2/ug.
In addition there can be large interferences from some other elements, particularly mid-z transition elements such as Mo.
To start things off I've attached a pdf of a paper just published on carbon doping of these magnesium borides and also a separate white paper on the details of the area peak factor (APF) shape corrections we utilized for previous work on the precursor magnesium borides, MgB2 and MgB4.
I'd be interested in seeing other efforts to quantify boron and what difficulties were encountered...