Yes because that is 0.1mS of blocking code. To minimise this then set the A/D converter in the free running mode and read it when required.
That sample rate is pushing it for a 16MHz processor. I have got an analogue input rate of about 56KHz when doing nothing else but save the samples in memory, but I was not trying to do anything else as well.
A simple sample in / sample out to D/A can run on that sort of processor at a about 16 Ksps ( samples per second ).