I'm not a professional grain inspector but based on experience with the grain I have sold, you're doing OK. The photos are on the dark side but I can see you have mostly whole kernels of corn. Yes, some are cracked or chipped whole kernels but a "whole" kernel is any kernel greater than 75% intact; this needs to constitute the majority of the sample to be considered corn grain. The medium-sized (<75% intact) pieces of cracked corn are still considered corn grain. Only the pieces of cracked corn about 1/8" in size or smaller will be counted against you as foreign material; along with dirt and dust. Beyond that... any stalk, weed seed, or diseased looking kernels will count as foreign material; which I can't see any of in the photos.
Your sample isn't *perfect*, but nobody's is. The goal is to: 1) maintain a sample that has a majority of whole corn, 2) minimize the small pieces of broken corn and dust, 3) minimize trash like stalks and cob pieces. Given these photos, I'd say your at around 2% FM (foreign material) on the high end and maybe just under 1% on the low end; which is definitely acceptable.