MEASUREMENT OF CALCIUM CONCENTRATION IN MEAT PRODUCTS

Calcium is extracted from the meat directly into an Ionic Strength Adjustment Buffer.

Equipment Required:

1. Ion Analyzer (recommended) or pH meter with millivolt scale
2. detectION 3041 calcium ISE

Reagents:

Ionic Strength Adjustment Buffer (ISAB) - This should be 0.1M Potassium Chloride (dissolve 7.45g of KCl in 1000ml distilled water). Calcium Stock Solution (0.1M) - Dissolve 11.1g of Calcium Chloride in distilled water in a volumetric flask and dilute to 1000ml. Reference Electrode Filling Solution (0.1M KNO₃) - Dissolve 10.1g of Potassium Nitrate in distilled water in a volumetric flask and dilute to 1000ml.

Standard Preparation:

Make up standards of 0.01M, 0.001M and 0.0001M by dilution of the 0.1M calcium standard in distilled water. Dilute these standards 1:1 with the ISAB.

Sample Preparation:

Prepare the sample by taking 1 g of meat and liquidizing with 100ml of distilled water. Centrifuge the mixture and to 20ml of the supernatant add 20ml of ISAB.

Method:

Immerse the electrode in each of the prepared standards in increasing

concentration steps, rinsing the electrodes in distilled water between

standards.

Plot a graph of mV response against standard concentration on semilog graph

paper.

Immerse the electrodes in the sample solution; record the mV response and plot

sample concentration from the graph.

Using the Model 135, this determination may be carried out directly in

concentration units, using the "Activity" modes.

Calculations:

To calculate the calcium concentration of the original sample multiply the result obtained from the graph (M130) or direct from the display (M135) by 100.