Membrane acetylcellulose

If sufficient nutrients (e.g., 0.3 g l 1 glucose) are present in a sample solution, a constant current is obtained from the electrode. The current depends on the total respiration activity of immobilized cells. Therefore, the total respiration activity of bacteria, the current, depends on the number of viable cells immobilized onto the acetylcellulose membrane. The relationship between the current and the cell numbers on the acetylcellulose... 

Membranes mostly made of acetylcellulose or more preferably polyamide. Large pressure differences mean complicated desalination plant construction (in some cases multistage). Pretreatment of water necessary as for distillation plants... 

The membranes are manufactured from acetylcellulose or, more preferably, polyamide. The technical construction is complicated and made expensive by the large pressure differences and the need for thin membranes. Bundles of coiled thin hollow capillaries (external diameter 0.1 mm, internal diameter 0.04 mm) are, for example, placed in a pressure cylinder (Fig. 1.1-3). The.se capillaries protrude from the ends of the cylinder through plastic sealing layers. Of the (high salt content)-water fed into the cylinder from the other side, 30% passes through the capillary walls into the capillaries and the rest is run off as concentrate and disposed of. An intensive and expensive pretreatment of the feed water is also necessary in addition to the removal of all colloidal and biological impurities, treatment of the feed water is also necessary e.g. by acid addition. The use of feed water from wells in the neighborhood of beaches is particularly favored. 

When trace amounts of phosphates were determined in water, they were preconcentrated (as the P-Mo blue) in a column packed with silane-coated glass beads DMF was used as the eluent [116]. The P-Mo blue may also be concentrated on a nitro- or acetylcellulose membrane in the presence of dodecyltrimethylammonium bromide [117]. 

Choline oxidase has been immobilized, using a variety of procedures, on hydrophobic agarose particles (Karube et al., 1979c), asymmetric acetylcellulose membranes (Mizutani and Tsuda, 1982), and nylon netting (Mascini and Moscone, 1986). Yao (1983) constructed a CME by direct fixation of choline oxidase on a silanized platinum net electrode via glutaraldehyde coupling. 

The enzymes were covalently bound to acetylcellulose membranes by glutaraldehyde and the membranes attached to oxygen electrodes. 

First immunosensors ovalbumin on a platinum wire electrode for ovalbumin antibody antibody to human immunoglobulin G (hIgG) in an acetylcellulose membrane on a platinum electrode for hIgG measurements [11,13]... 

Adsorption of Escherichia coli cells onto acetylcellulose membranes and attachment of the membrane to a Teflon membrane of an oxygen electrode Screening of mutagens [62]... 

Use of membranes — Antibodies can be immobilized on membranes, which can be easily attached to the sensitive component of a transducer. Bromo-acetylcellulose membranes are first immersed in a solution containing hexamethylene diamine, and then into diepoxybutadiene, which produces the groups that will react with the antibody (Figure 3.13). Finally, the membrane with the bound antibodies is rinsed with a solution of ethanolamine to block any unreacted epoxy groups [74-76]. 

Figure 3.13 Immobilization of an antibody on a bromo-acetylcellulose membrane.

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