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From: larry@kitty.UUCP (Larry Lippman)
Subject: Re: looking for thick liquids
Summary: Everything you ever wanted to know about chemistry of K-Y Jelly :-)
Date: 28 Dec 90 04:59:08 GMT
Organization: Recognition Research Corp., Clarence, NY

In article <1990Dec27.150503.13692@kodak.kodak.com>,
ornitz@kodak.kodak.com (Barry Ornitz) writes:

> One simple material would be sodium carboxymethyl cellulose.
> ...
> BTW, an already mixed solution of CMC in water is sold as KY Jelly.

        K-Y Jelly also contains sodium alginate and a small quantity of
EDTA.  The EDTA is used to sequester calcium ion impurities in the sodium
alginate, with the effect of such calcium ions being undesirable high
viscosity when the product is at lower temperatures.  Don't ask about
the "lower temperatures" - I never did get an answer to that question,
and that's simply the way the product is (or was at one time) formulated.

        Sodium alginate is an anionic substance which forms aqueous
dispersions that are pH neutral.  The sodium alginate and the CMC appear
to have a synergistic effect upon each other which results in a stable
and relatively inert lubricant.

        I suppose some readers may be wondering how I know so much about
the *precise* chemical composition of K-Y Jelly... :-)

        It seems that I once had the dubious experience of performing a
forensic chemical examination of what appeared to be traces of lubricant
on the clothing and perineum of an assault victim, and comparing same
with a tube of K-Y Jelly found in a search of a suspect's residence.
Johnson & Johnson, the manufacturer of K-Y Jelly, was cooperative in
providing chemical formulation data on this product.  The essential presence
of K-Y Jelly on the victim was ascertained through IR spectroscopy.  The
interesting part was that flame photometric determination (no AA was available
at the time) of sodium and calcium concentration from the victim's specimen
correlated almost exactly with the concentrations taken from the sample
seized from the suspect.  With some help from J&J, it was learned that
enough sodium and calcium differences existed due to lot variation such
that based upon the above analysis one could state with reasonable certainty
that the K-Y specimen from the victim was consistent with the K-Y taken
from the suspect.  At least it did not appear possible for the defense to
prove that the samples were *not* consistent.  Fortunately, or unfortunately
as it may have been, I never had the opportunity to present this evidence
in court since the suspect plead to a lesser charge.

        After the above experience, how could I ever forget the composition
of K-Y Jelly as long as I live? :-)

Larry Lippman @ Recognition Research Corp.  "Have you hugged your cat today?"
VOICE: 716/688-1231   {boulder, rutgers, watmath}!ub!kitty!larry
FAX:   716/741-9635                  {utzoo, uunet}!/      \aerion!larry

 
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