522 PATENT ABSTRACTS

4909908 ceptable organic solvent. A preparative method of purifying proteins such as HSA or BSA and

E L E C T R O C H E M I C A L recombinant deoxyribonucleic proteins using C N C E N T R A T I O N D E T E C T O R reversed phased PHLC is also described.

M E T H O D

Pepi Ross, Marc J Madou, Zoil Reyes, Joel F Jensen, Sharon W Wing, Virginia G Rimer

Electrochemical biosensor systems or ap- paratus, components thereof, and methods for quantitatively measuring or assaying concentra- tions of selective substrates or metabolites in aqueous media as a function of electrochemical response to hydrogen peroxide concentration, using immobilized enzyme electrode means selective for the substrate or metabolite being measured.

4909921

E L E C T R O C H E M I C A L S E N S O R F A C I L I T A T I N G R E P E A T E D

M E A S U R E M E N T

Narushi Ito, Tokyo, Japan assigned to NEC Corporation

An electrochemical sensor wherein a FET for measuring chemical substances and a reference electrode are covered with a continuous hydrous polymer on an insulating substrate, and on the hydrous polymer, an enzyme-immobilized film is formed in a region positioned on a channel part of FET for measuring chemical substances.

4909941

H I G H P E R F O R M A N C E L I Q U I D C H R O M A T O G R A P H Y M O B I L E

P H A S E

Dick J Poll, David R K Harding, William S Hancock, Palmerston North, New Zealand

There is described a mobile phase for use in the purification of proteins using reversed phase HPLC on a preparative scale. The mobile phase is an aqueous solution containing 0.005 to 1M of a physiologicially acceptable acid of the general formula YCOOH where Y is a polar electron withdrawing group capable of hydrogen bon- ding silanol groups. The solution also contains up to 95% by volume of a physilogically ac-

4910134

A S C O R B I C A C I D D E C O M P O S I N G M E T H O D

Kazuhiko Yamanishi, Toshiro Hanada, Tokyo, Japan assigned to Wako Pure Chemical Indus- tries Ltd

A method for decomposing ascorbic acid in a sample is descirbed wherein in the method water and dehydroascorbic acid are produced without generation of hydrogen peroxide characterized in that the decomposition is conducted in the presence of copper ion, peroxidase and at least one other compound selected from the group consisting of: 4-aminoantipyrine, 3-methyl-2 benzothiazolinonehydrazone, 2, 2'-azinobis(3 ethylbenzothiazoline-6 sulphonic acid), a triphenyl methane type leuco compound, a phenol comound, an aniline compound, and a naphthol compound.

4910139

M E T H O D F O R C O N T I N U O U S L Y P R O D U C I N G C I T R I C A C I D BY

D U A L H O L L O W F I B E R M E M B R A N E B I O R E A C T O R

Ho Nam Chang, Bong Hyun Chung, Seoul, Republic Of Korea assigned to Korea Advanced Institute of Science and Technology

Aspergillus niger B60 was immobilized in a dual hollow fiber bioreactor to produce citric acid continuously. The fungi proliferated well in the interstitial region formed by a parallel arrange- ment of three microporous polypropylene hol- low fibers contained within a silicone tube. Excessive fungal cell growth could be controlled by supplying a nitrogen-deficient medium at the production stage, and also uniform cell distribu- tion in the reactor could be obtained by changing the direction of medium flow. With pure oxygen aeration and nitrogen-deficient medium, volumetric productivity reached 1.62 g/I.h at a residence time of 4.02 h, which corresponded to a 27-fold increase over that of shake-flask fermen- tation. When the residence time was increased to 20.1 h, citric acid at a concentration of 26 g/l was