1) Is it necessary to use some antialiasing filter in the input of ADc for DC measuring only? (12bit, about 10 ksps, only DC signal) 2) Is it suitable to use 0.1uF ceramic capacitor in parallel with 10uF CERAMIC capacitor (both SMD, 0805 size) for decoupling ADi parts such as Operational Amplifiers, Voltage References, ADc,...(16 bit and 12 bit applications)? There is smaller, low-priced version of recommended 10uF tantalum in parallel with 0.1uF ceramic (various ADi datasheets).
1)Without an antialiasing filter any noise picked up by the i/p pin can be aliased back to the passband of the ADC. So yes, an antialiasing filter is required even for DC i/p signals. 2)A ceramic 10uF capacitor should give no problems.