298 94 307/02 Untersuchungen zum Stand der Umsetzung des ...

See description under 1 Limed bone process.
J Drying
See description under 1 Limed bone process.
Teil 3 Seite 6-20
3 ACID BONE PROCESS WITH ALKALINE PRETREATMENT
A Degreasing
See description under 1 Limed bone process.
B Demineralisation/acidulation
See description under 1 Limed bone process.
L Alkali pretreatment
Following demineralisation/acidulation, the ossein is soaked twice in water, each “soak”
lasts one hour and uses an equal volume of water to ossein. After each “soak”, the water
is drained away. The ossein is further washed by stirring for 10 minutes with equal vol-
ume of water to ossein and then drained.
One volume of 0.3 N sodium hydroxide (pH > 13) is added to the ossein and allowed to
stand for 2 hours, with occasional agitation. The pH is monitored, recorded and main-
tained above pH 13.0, by addition of more sodium hydroxide solution, as required.
After the alkaline “soak”, the solution is drained and the ossein is washed twice. Each
wash lasts for 15 minutes and uses equal volume of water to ossein. Finally, the ossein is
washed for 10 minutes with twice the volume of water to ossein.
M Acid treatment
1.2 times the volume of water compared to ossein are added to the alkaline-pretreated
ossein and by means of small additions of 1 N hydrochloric acid. A pH of 2 is maintained
for up to 6 hours, using occasional agitation.
The ossein is then washed a number of times, each wash using an equal volume of wa-
ter to ossein, for at least 2 hours, until the pH is 2.5 or above.
E Extraction
See description under 1 Limed bone process. For acid bone extraction, the extractors
can be plastic coated.
F Filtration
See description under 1 Limed bone process.
G Ion exchange
See description under 1 Limed bone process. In some acid bone processes the anion
exchanger is placed before the cation exchanger.
H Concentration
See description under 1 Limed bone process.
I Sterilisation