Eliminating acceleration data from quaternions

I am using 2 IMU sensors. The only data I receive is a set of quaternions from both these sensors. I have already found out the accelerations (due to gravity, I guess) in these sensors from the same quaternions by using the formulae - ax = 2(q1*q3+q0*q2), ay = 2(q2*q3+q0*q2), az = q0^2-q1^2-q2^2+q3^2. I have also got the euler angles (by using function quat2eul) from the same quaterions of both the sensors. But it seems that the euler angles/quaternions have acceleration information included in them. I actually want to eliminate accelerations from quaternions and have quaternion with only pure orientation or angular quaternion information. Please note that eulers as well as acceleration data are obtained from the same set of quaternions. Any guidance will be helpful and appreciated. Thank you!

[James Tursa]

Can you give more detail on the IMU sensor data? And maybe post some sample data?