RE: Rad. end Env.Biophys.

["Akbarzadeh, Mansour" <AkbarzM@wipp.carlsbad.nm.us>]

-----Original Message-----Paul Lavely wrote,

We have been performing analysis of some human
> urine samples for
> levels of tritium that are at the lower end of
> our LSC to measure. We
> have been distilling the urine to rid it of the
> color and chemicals
> other than water. This distillation process is
> more than a burden.
> Does anyone use a process that would eliminate
> the distillation
> process?
>
Paul,
One of the best procedures for H-3 in urine sample is freeze-drying method (It
has been a long time that I have done H-3 in urine!). In this method, which
requires special Apparatus (i.e. "cold finger" glass-ware and attached
cylinder, sealed vacuum system...etc), ~20 ml of urine is aliquoted and
freeze-dried using dry-ice and acetone mixture. All collected water samples
are clear(total volume of water collected, is between 15-18 ml based on the
salt content in urine). If Wallac LSC Instrument is used, 10.0 ml of Collected
water sample is transferred to an LSC vial and 10.0 ml of "Hi-Safe" cocktail
is added. For Packard LSC Instrument, 8.0 ml of collected water sample and
12.0 ml of "Insta-Gel" cocktail is used. Counting time varies between 50-100
Min. depending on desired detection limit.    

Regards,
Mansour Akbarzadeh
WIPP Laboratories
(505)234-8617
akbarzm@wipp.carlsbad.nm.us

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