• Food salt content tester

Food salt content tester

Model 926 is used for the determination of chloride ions. It is an instrumental analogue of "Argentimetry", the traditional titrimetric methods using silver nitrate reagent. 

Like these classic methods it relies on the chemical formation of the very insoluble salt, silver chloride. The importance of chloride determination has been realized for well over a century, with many variations and changes being made to the techniques in order to improve the detectability and selectivity. Research into the analysis of chloride was conducted by Gay-Lussac (1832), Level (1853), Mohr (1856) and Volhard(1874) and their findings have proven to be the basis of the methods which are still in common use today.

Key applications areas

The measurement of Salt (Sodium Chloride) concentration in the Food and Dairy Industry is universal. The ability to read direct in Salt concentration makes the model 926 the instrument of choice for manufacturers and food analysts around the world. Salt and salinity also represents serious contamination in Industrial processes and the sensitivity of the coulometric method enables measurement in the ppm range in boiler feed water, polymer washes. bore hole slurries, as well as soils analysis and others. The 926 has proven itself to be the method of choice for many desalination studies and general quality control of sample lines.

Clinical measurement of the chloride ion is essential for monitoring of electrolyte balance of patients as it plays, in combination with sodium and potassium, an important part in maintaining water balance between cells, plasma and interstitial fluid. The Model 926s is also widely used in the confirmation of the diagnosis of Cystic Fibrosis. The model 926S variant can accept 20 microlitre samples. Sherwood Scientific has method notes for these and other Applications. Pharmaceutical Production, Cement Manufacture, Photography Veterinary.


Principles of methods
The main difficulties with the classic method were that silver nitrate reagent would change on storage due to a photochemical reaction and that the titration end point is visually weak. The reagent would have to be standardized requiring a highly skilled analytical technician . The 926 method is based on a coulometric titration and is an absolute method where the reagent, the silver ions, is precisely and quantitatively generated at the time of the analysis by passing a constant current between donor electrodes. The end point is detected by the use of sensing electrodes which measure the change in solution conductivity which occurs when excess silver ions are present in solution.


Reagent system
The Buffer system is optimised to eliminate interfering ions and incorporates a special dispersant to ensure reproducible formation of the silver chloride precipitate and enhance analytical performance.


  • Fertiliser Manufacture
  • Soil Analysis
  • Plant Analysis
  • Feed Analysis*
  • Cake and Flour Manufacture*
  • Quality Analysis of Final Product
  • Chemical Additive Analysis*
Brewing and Wine Production
  • Water Analysis Prior to Brewing
  • Soil Analysis
  • Added Salts Quality Control
  • Hop and Grape Analysis
Cement manufacture*
  • Quality Control of cement During Drying Process
  • Preparation of Gypsum and plaster Board
Dried Egg manufacture
  • Preparation and Determination of Shelf Life and Stability
Meat and Fish Processing
  • Determination of Added Salt in Curing Process*
Protroleum and oil Production
  • Determination of Salt Concentration in Bore Slurries*
  • Water Analysis
  • Antibiotic Production*
  • Quality Control of Chemicals used in Drug Manufacture
  • Determination of Chloride in Fixing and Developing Solutions
Food Manufacture
  • Chloride Measurement in Tomato/Friut Juices*
  • Chloride Determination in canning Liquors, Brines
  • Quality control of Final Package after Food Preparation
  • Chloride in Yoghurt Manufacture
  • Freeze Drying of Food Preparation


Model 926
Model 926S
Sample size
500 microlitres
20 microlitres
Readout Range
10-999mg Cl/l; 2-165mg%Salt
Analysis Time
35 sec @ 200mgl/l
35 sec@ 100mmolCl/l
SD <1% @ 0.1% Cl Std Solution
+-2% @ NQCS 100mmol/l
1% in range 10-999mgCl/l
1% 10-299 mmolCl/l
Reproducibility CV for 20 replicates
<1.5% @ 200mgCl/l
<1.5% @ 100mmolCl/l