Hi! Recently, I've modified 1H-1H COSY pulse sequence (Bruker DRX 500Mhz at TopSPin1.3) to 31P-31P (1H decoupled) COSY. I don't remember whether I used simple gCOSY or DQF-COSY, but it's irrevelant. Pulse sequence was modified by adding proton decoupling during acqusition, I think it was garp, (just like in almost forgotten HETCOR sequence). I'll paste here full sequence as soon as It'll be found in my library. In case of any questions you can write then here, at board, or via e-mail: aleniak@icho.edu.pl aleniak@icho.edu.pl

Before that you should try typical gCOSY without decoupling. You need just calibrated 90deg 31P hard pulse.