Texmaker: command not found on MacOS El Capitan

I had a similar problem with texmaker on El Capitan yesterday which gave me a sh: repstopdf: command not found whenever I was trying to use a new eps graphic in my document. Apparently changing the specific paths to pdflatex etc. is not enough and it might still try looking for some binaries (when needed e.g. for converting images) in /usr/texbin.

I found a solution here which suggests using the input field at the bottom of the command settings tab to add /Library/TeX/texbin/ to the PATH variable. After that everything worked fine for me. I'm a bit surprised that it doesn't find pdflatex in your case though because you have probably specifically set its path to /Library/TeX/texbin/pdflatex, but I hope that this still solves your problem.

So my settings now look like this:

Note the active input box at the bottom which sets the PATH for the other binaries.