The person who has control of a seized or held lot that is found to be in violation of this chapter may appeal the result of the analysis to the secretary, in writing, within 15 days of receiving the notice of violation. Upon receipt of that appeal, the secretary shall take a further sample of the lot in question for analysis. The cost of sampling and analysis shall be at the expense of the person who requests the further sample. The findings of the analysis on appeal shall be conclusive.