I don't agree. Chlormamine shows up fine on a total chlorine test (why do you believe that is not true???), and it is what I recommend folks test their effluent for if concerned.
Chloramine kits are generally more expensive, and not needed unless you actually want to prove it is chloramine.
The directions for the Hach total chlorine kit make that clear:
Chlorine can be present in water as free chlorine and as combined chlorine. Both forms
can exist in the same water and be determined together as total chlorine. Free chlorine is
present as hypochlorous acid and/or hypochlorite ion. Combined chlorine exists as
monochloramine, dichloramine, nitrogen trichloride and other chloro derivatives. The
combined chlorine oxidizes iodide in the reagent to iodine. The iodine and free chlorine
react with DPD (N,N-diethyl-p-phenylenediamine) to form a pink color which is
proportional to the total chlorine concentration.
To find the concentration of combined chlorine, run a free chlorine test and a total
chlorine test. Subtract the results of the free chlorine test from the total chlorine test to
obtain the combined chlorine concentration. The measurement wavelength is 530 nm for
spectrophotometers or 520 nm for