Any person who exposes or offers for sale or delivers to a purchaser any food shall furnish within business hours and upon tender and full payment of the selling price, a sample of such food, to the Commissioner, and who shall apply to such manufacturer or vendor or person delivering such food to a purchaser for a sample in sufficient quantity for the analysis of the article in his possession. Samples may be purchased on the open market and shall be representative samples; the collector shall also note the name of the vendor and agent through whom the sale was actually made, together with date of purchase, and all samples not taken in unbroken and sealed original packages shall be sealed by the collector in the presence of the vendor with a seal provided for the purpose. When possible, samples shall be unbroken and sealed original packages, or taken out of unbroken and sealed original packages. Three like samples shall be obtained where the article is in the original package, or if not in the original package the sample obtained shall be divided into three equal parts and each part shall be labeled with the marks, brands, or tags upon the package, carton, container, wrapper, or accompanying printed or written matter. One sample shall be delivered to the party from whom purchased, or to the party guaranteeing such merchandise; two samples shall be sent to the Commissioner, one of which is to be analyzed, as provided in this chapter, and the other shall be held under seal by the Commissioner.