MFLP-45: DETERMINATION OF SODIUM CHLORIDE (SALT) IN FOODS AND OTHER SAMPLES BY QUANTAB™ CHLORIDE TITRATORS

Laboratory Procedure MFLP-45
November 2007

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Richard Caldeira
Evaluation Division
Bureau of Microbial Hazards, Food Directorate
HPB, Address Locator 2204A1
Ottawa, Ontario KIA 0L2

E-mail: Don_Warburton@hc-sc.gc.ca

1. APPLICATION

This method can be used to determine chloride content of most foods. The kit will provide results as % sodium chloride or ppm Cl- ions on a wet weight basis. In order to determine % brine it will be necessary to determine the moisture content of the sample. If a regulation specifies an Official Method then that method should be followed such as FO 38 for % salt in smoked fish products. This revised method replaces MFLP-45 dated April 1997.

2. PRINCIPLE

Quantab™ Chloride Titrators are convenient test devices used to measure the chloride content in aqueous solutions or dilute aqueous extracts of solids. These devices contain all the reagents necessary to carry out standard chloride titration. The titrators are pre-calibrated and provide quantitative results which are easy to read and interpret.

Quantab is a registered trademark of Environmental Test Systems, Inc., Ames Co. a Division of Miles Laboratories Inc., Elkhart, IN.

3. DEFINITION OF TERMS

See Appendix A of Volume 3.

4. COLLECTION OF SAMPLES

See Appendix B of Volume 3.

5. MATERIALS AND SPECIAL EQUIPMENT

1. The reagents for the Quantab™ are provided in the kit, which is available from:
   
   Fisher Scientific, 112 Colonnade Rd. Nepean, Ontario K2E 7L6 613-225-8874 or 1-800-267-3540; catalogue no AM 1176 or from: VWR 178 Hanson St. Toronto, Ontario, M4C 1A7, 416-699-5555 or 800-932-5000; catalogue no 66130-502.
   
   
2. The method requires test tubes (16x100 mm) [50 mL beakers may be substituted], filter paper (Whatman #1) and glass funnels

6.0 PROCEDURE

All other specific information related to either materials, equipment, general procedures, and interpretation of results can be found in the information summary sheet accompanying the test kits.

Note: all weights and volumes must be accurate!

6.1 It is imperative that a representative portion of the sample be removed from the sample unit and blended in a mason jar for two minutes.

6.2 Remove 10 g of finely blended sample and add 90 mL of boiling water and blend for 30 s. Allow to sit for one minute then blend again. Cool to room temperature. Filter at least 5 ml through a Whatman #1 filter paper folded into a cone as specified and supported in a conical funnel.

6.3 Insert Quantab™ Chloride Titrator into filtrate in the test tube and follow test procedure.

7. RESULTS

7.1 Determine the height of the white column in Quantab™ units within the time specified (2-30 minutes). Samples should be diluted so that results are within a readable range for the selected strip.

8. CALCULATION of % Sodium Chloride

8.1 Follow the directions specified in the kit to calculate % Sodium Chloride.

9. INTERPRETATION

9.1 Follow manufacturer's instructions. If no sodium chloride is detected report as less than the detection limit based on the strip used and amount the sample was diluted.

10. CALCULATION of % Salt in the Water Phase or % Brine

10.1 Determine the % moisture in the food using an acceptable method for the food being examined. Consult the Official Methods of the Association of Official Analytical Chemists (AOAC) or equivalent for the selection of an acceptable method.

10.2 Determine the % salt or grams of salt in the Water Phase (WPS ) or % brine using the following equation.

% salt in the Water Phase (WPS ) or % brine =	[% Sodium chloride]	x 100
	[% Sodium chloride + % moisture]

OR

% salt in the Water Phase (WPS ) or % brine =	[ grams Sodium chloride]	x 100
	[grams Sodium chloride + grams moisture]

10.3 Report % sodium chloride determined from the Quantab™ strip and % moisture values