Quantification of Carboxylation of SPIO

1. Prepare 100mM solutions of NaOH and HCl.

2. Obtain 10 mL of particles in a clean beaker.

3. Calibrate pH meter.

• a. Check standard solutions for contamination.

• b. Remove probe and rinse with water.

• c. Press ‘Cal’ – the 7.0 light will flash.

• d. Insert probe into pH 7.0 buffer; when reading stabilizes, press ‘Read’.

• e. Rinse probe with water.

• f. Press ‘Cal’ – the 4.0/10.0 light will flash.

• g. Insert probe into pH 4.0 or 10.0 buffer; when reading stabilizes, press ‘Read.’

• h. Rinse probe again and insert into sample to be analyzed.

4. Particles are stored in neutral solution; choose whether to bring solution to basic or to acidic. Do not exceed a basic pH of 11 or an acidic pH of 2.

5. Add either acid or base in somewhat large quantities to bring solution to extreme pH (~100 μL).

6. Then add the other (acid or base) in small quantities (~10 μL) recording pH after each addition.

Created: 06/21/2007 Brian Lee