A Defense Counsel Should Possess Adequate Knowledge When Examining an Expert Witness
Mark Rosenfeld: However in Respondent’s case, there’s actually four peaks, not two.
Expert: I would agree that there is one that’s also visible between the ethanol and the n propanol peak, which is given at retention time 1.078 minutes, and I see that there is a minor peak just before the ethanol peak, it’s 0.736 minutes.
Mark Rosenfeld: When you run your internal standards and your quality control checks, are those other peaks at 0.736 minutes and 1.078 minutes present in the quality control?
Expert: No, they should not be.
It Is Possible for a Blood Sample to Be Tainted by the Presence of a Contaminant
Mark Rosenfeld: What, what are, let’s just start with the one in between the ethanol and the n propanol. At 1.078 minutes there is a peak, what is it?
Expert: I haven’t to this day identified what that peak is.
Mark Rosenfeld: Is it possible that it’s a contaminant?
Expert: Uh, well, by contaminant, if we say that it is simply peak that we’re not interested in including in the analysis, uh, yes, that is safe to say.
Mark Rosenfeld: Okay. Now, with the peak before the ethanol peak, at 0.736, is that a contaminant?
Expert: Well, I again, I also would agree that that is an additional chemical compound like the first, that we’re not interested in clearing in the analysis or considering.
Mark Rosenfeld: Okay. Do you know what that peak is at 0.736 minutes?
Expert: No.
Mark Rosenfeld: Okay. In order for there to be a, an accurate ethanol peak, it must be sufficiently separated from any other compounds, correct?
Expert: Yes, that’s correct.
Any Inconsistency in a Blood Report Can Be Utilized as a Viable Defense
Mark Rosenfeld: Does the first peak, the unknown peak at 0.736 reach the baseline at the end of the peak?
Expert: Well, the uh, the clear graphic system has deduced that by including the check mark where the peak, the end of peak elution time, uh….
Mark Rosenfeld: That’s the…the computer saying, we are saying that the peak ends here, but I’m asking you as the analyst, does the peak reach the baseline?
Expert: It does not reach the uh, established baseline at the beginning of run.
Mark Rosenfeld: So that is inconsistent with the method that your lab uses in analyzing ethanol is gas chromatography?
Expert: Well it’s a… I’m, I hesitate to say it’s inconsistent with the method; it’s acceptable with the method that we use.
Mark Rosenfeld: Is there separation between the first peak and the second peak?
Expert: There is no absolute baseline separation between those two peaks.
Mark Rosenfeld: As chromatography is a separation science?
Expert: Yes, that is correct.
Only an Accurate Reading May Be Considered a Legitimate Piece of Evidence
Mark Rosenfeld: In order for there to be a good, accurate, trustworthy sample, there should be separation between the first and the second peak.
Expert: Well, that’s not always required in our analyses. There should be a sufficient amount of separation, so that it doesn’t interfere substantially with what you’re trying to analyze.
Mark Rosenfeld: And in this case there is no separation.
Expert: There, there is a, there is a separation, it’s not absolute.
Mark Rosenfeld: Okay. Does the ethanol peak have a tail?
Expert: It does, yes.
Mark Rosenfeld: Does the n propanol peak have a tail?
Expert: Yes, it does.
Mark Rosenfeld: Are those tails what you would like to see in good chromatography?
Expert: Well, those tails are often seen in chromatography done in all cases. It’s not the ideal situation from an ideal column.
Personal Attention
