HANNA HI84429 Titratable Acids Mini Titrator and pH Meter for the Dairy Industry

HI 84429 is a low cost, easy to use, automatic titrator and pH meter that reflects HANNA’s years of experience as a manufacturer of analytical instruments. HI 84429 performs automatic analysis with all the necessary calculations through a clear and simple interface.

This advanced automatic titrator and pH meter has a powerful and effective built-in algorithm to analyze the shape of the pH electrode response and determines the reaction completion. By pressing the START key, the instrument automatically conducts an endpoint titration the and result is immediately displayed. The HI 84429 has a simple and reliable peristaltic pump to ensure accuracy in dosing and repeatability in measurement.

The HI 84429 comes with a pre-programmed analysis method designed for total titratable acidity measurements on milk. The determination of total acids in dairy products is made according to a neutralization reaction; that is the reaction between the acids found in dairy products and a base. This type of reaction forms the basis of titration methods of analyzing acids. Titratable acidity is measured on a degassed sample at the endpoint of 8.30 pH. The results are expressed in °SH, °Thm °D or % l.a.

Acidity Measurement and Its Significance in the Dairy Industry

There are two fundamentally different conventions for expressing acidity in dairy products: titratable acidity and pH. The pH is a measurement of hydrogen ion concentration while titratable acidity is the neutralizing capacity by a base.

Acidity affects taste, thus this parameter is tested to determine the quality of the milk product. As milk acidity increases over time, measuring this parameter is also a means of monitoring storage conditions. Acidity is determined by an endpoint titration using sodium hydroxide (a base) and is defined as the consumption of base necessary to shift the pH value from 6.6 (corresponding to fresh milk) to a pre-determined basic pH value. While pH 7.0 is the actual point of neutralization, phenolphthalein is commonly employed as a color indicator to determine the endpoint of reaction and with it, color change occurs at pH 8.3. Titratable acidity is expressed as one of a variety of units, the use of which reflects the titration method and strength of base employed during titration.

°SH — Soxlet Henkel degrees: obtained by titrating 100 mL of milk with 0.25N NaOH, using phenolphthalein as the indicator. This method is common in Central Europe.

°Th — Thorner degrees: obtained by titrating 100 mL of milk thinned with 2 parts distilled water, with 0.1 N NaOH, using phenolphthalein as an indicator. Method is used mostly in Sweden and the CIS.

°D — Dornic degrees: obtained by titrating 100 mL of milk thinned with two parts distilled water, with 0.9N NaOH, using phenolphthalein as an indicator. Used mostly in the Netherlands and France.

% l.a. — percent lactic acid: obtained as °D divided by 100. Frequently used in the UK, USA, Canada, Australia and New Zealand.

Note: Taking into account the concentration of sodium hydroxide, the results expressed in one value can be easily converted into any other unit value by consulting the chart at right.

The HI 84429 Mini Titrator eliminates the subjective endpoint color change detection determined by the human eye, and instead employs the sensitivity and accuracy of a pH sensor. The titration method is a potentiometric endpoint determination using a pre-determined pH value.

Acidity of dairy products can be expressed in any of the units described earlier by simply selecting the desired unit. After performing a pump calibration with the supplied standard, you can then make titrations, expressed in the desired unit, using the same titrant. This eliminates the inconvenience of changing tubes, purging the titrant for tube cleaning and being sure that you have the right titrant concentration – saving time and titrant. The quantity of sample needed is much smaller in comparison to a traditional method, where 100 mL of product is used.

Order Information:
HI 84429-01 (115V) and HI 84429-02 (230V) are supplied with FC 260B pH electrode, HI 5315 Reference electrode, HI 7072 Filling solution (30 mL), HI 7662-M temperature probe, HI 84429-50 titrant (100 mL), HI 84429-55 Standard (500 mL), HI 700640 cleaning solution for milk deposits (20 mL, 2), pH 4.01 buffer solution (230 mL), pH 6.00 buffer solution (230 mL), pH 8.30 buffer solution (230 mL, 50 mL beakers (2), 20 mL beakers (2), tube set with cap, stir bars (2 small, 2 large), power cord, 1 mL syringe, capillary dropper pipette and Instruction manual.