Karl Anthony Guydon was convicted by a jury of two counts of delivery of a controlled substance (crack cocaine), and was sentenced to twelve years on each count, to be served concurrently. Guydon’s sole point on appeal is that the trial court erred in allowing the introduction of the controlled substances because there was a discrepancy in the weights, and the State failed to prove a proper chain of custody. We agree, and reverse and remand for new trial.
On June 4, 1998, Ron Messer, a Little Rock police officer working undercover, went to Guydon’s residence and made two separate purchases of what was allegedly crack cocaine for $20 each. Messer testified that he turned the off-white, rock-like substance over to Investigator Scott Leger. Leger testified that when Messer gave the substances to him, he weighed them, placed them in sealed property envelopes, and initialed the envelopes and transported them to the crime lab in Little Rock. He further testified that State’s Exhibit 1 weighed three-tenths of a gram and State’s Exhibit 2 weighed two-tenths of a gram, that he did not transport the drugs to the crime lab until June 18, and that they were in a personal-property locker until that time. Kathy Shanks, a chemist with the Arkansas State Crime Lab, testified that she did the analysis on the two exhibits, which she described as two hard, off-white, rock-like substances. She identified her initials and laboratory case number and the date and time that she performed the analysis, and testified that Exhibit 1 weighed a total of 0.1828 grams, that Exhibit 2 weighed 0.1183 grams, and that both tested positive for cocaine base and benzocaine.
At that time the State moved to introduce the two exhibits, and Guydon’s counsel requested permission to voir dire the witness. During voir dire, Shanks testified in pertinent part that: the exhibits were tested on October 26, 1998; identified two other workers who received the evidence and brought it to her; stated she did not know who placed it in the secured locker, if it was in a sealed condition, or if proper lab protocol was followed and stated only that it was sealed when she received it.
Guydon’s counsel then objected to the admission of the exhibits based on the substantial difference in the testimony of Officer Leger and Ms. Shanks regarding the weight of the drugs, and the fact that at least two persons in the chain of custody were not there *287to testify. In response the State contended that there was no evidence of tampering and that there had been substantial compliance with the chain of custody. The trial court overruled Guydon’s objection and admitted the two exhibits into evidence.
We first address the State’s contention that Guydon has failed to preserve this issue for appeal because he failed to make his chain-of-custody objection until the physical evidence was offered into evidence and after the crime lab chemist had testified that the substances were cocaine. Guydon objected immediately after the chemist’s testimony revealed the weight discrepancy and the break in the chain of custody. Our Supreme Court has said that such an objection must be made at the time the evidence in question is offered. See Pryor v. State, 314 Ark. 212, 861 S.W.2d 544 (1993). Consequently, the issue is preserved and we must address the merits.
The purpose of the chain of custody is to prevent the introduction of evidence which is not authentic. Gomez v. State, 305 Ark. 496, 809 S.W.2d 809 (1991). To prove its authenticity, the State must demonstrate a reasonable probability that the evidence has not been altered in any significant manner. Id. It is not necessary that every possibility of tampering be eliminated; it is only necessary that the trial court, in its discretion, is satisfied that the evidence presented is genuine, and in reasonable probability, has not been tampered with. Dixon v. State, 310 Ark. 460, 839 S.W.2d 173 (1992). Any minor discrepancies are for the trial court to weigh and, absent some evidence of tampering, the trial court is accorded discretion, and its ruling in this regard will not be reversed on appeal absent an abuse of discretion. Holbird v. State, 301 Ark. 382, 784 S.W.2d 171 (1990).
Here, we cannot say that the difference between 0.3 and 0.1828 grams, or between 0.2 and 0.1183 grams is insignificant or minor, any more than a discrepancy between 30 and 18 grams or between 20 and 11 grams would be considered minor. Moreover, although small quantities of contraband are involved in this case, our criminal statutes pertaining to illegal contraband provide that such small amounts are a basis for imposing years of penitentiary time; surely a reasonably accurate weight determination cannot be said to be simply a “minor” matter.
*288We find this case analogous to Crisco v. State, 328 Ark. 388, 943 S.W.2d 582 (1997), in which the supreme court held that the trial court abused its discretion by receiving into evidence contraband that was not properly authenticated due to a marked difference in the description provided by an undercover officer and a crime lab chemist. The supreme court held that because there was a significant possibility that the evidence tested was not the same as that purchased by the officer, the State was required to do more to establish the authenticity than to simply trace the route of the envelope containing the substance. Although the discrepancy in Crisco involved color and texture, and this case involves only weights, we conclude that the underlying rationale expressed in Crisco holds true in this case. Here, there was a marked difference in the two weights testified to by the officer and the chemist, and no attempt made by the State to establish the authenticity of the drug tested other than by tracing the route of the envelope.
In sum, there are several factors, not simply the weight discrepancy standing alone, that combine to mandate reversal of this case. First, the supreme court has said that the proof of chain of custody for interchangeable items like drugs or blood needs to be more conclusive. Id.; Lee v. State, 326 Ark. 229, 931 S.W.2d 433 (1996). Second, the discrepancies in the weights involved in this case are significant enough to raise an inference of at least the possibility of tampering. Third, the discrepancy is unexplained by the State. Fourth, all persons who handled the evidence were not present to testify.
Surely, neither the trial court nor this court should attempt to play chemist, and fill in the missing explanation for the discrepancy in this case, any more than the supreme court did in Crisco. Of course, the State is not precluded by this holding from attempting to properly authenticate these exhibits on retrial of this case.
Reversed and remanded.
Griffen, Hart, Jennings, and Neal, JJ., agree.
Meads, Crabtree, Pittman, and Bird, JJ., dissent.