Evaluation of a Compact Differential Cell for Secondary pH Measurements by a Bilateral Interlaboratory Comparison

Abstract

This work presents a new differential potentiometric cell for the standardization of pH buffer solutions and its evaluation, by means of a bilateral interlaboratory comparison, in relation to a traditional Baucke cell. The results obtained with the two cells were exactly the same for three of the pH buffer solutions analyzed (1.68, 4.01, and 6.86) and similar to each other for the remaining buffer solution (9.18). The new cell showed an average measurement time of only 21 minutes, in comparison with one to three hours for other cells described in the literature (including the Baucke cell).

Borax buffer solution for pH measurement: Homogeneity and stability studies and its application in the proficiency testing program

“…The Baucke cell was firstly introduced in 1994 [6]. A schematic diagram of the differential potentiometric cell system used in this measurement is shown in Figure 1.…”

“…After that, the hydrogen (H2) gas was fed into each cell under the flow rate of 500 ml/h [10]. It should be noticed that H2 gas was pre-humidified before entering the Baucke cell by passing H2 into two chambers containing borax buffer solution [6]. Both, cell and the cell chamber A r t i c l e i n P r e s s 4 were placed into the water by keeping its temperature at 25 °C using chilled circulation system.…”

“…pH measurement is also one of the parameter in the PT program of MiC Lab-LIPI because the pH measurement is very common and widely used in quantitative measurements in the field of chemical analysis [6]. In addition, the data obtained from pH measurement is widely used as the basis for making environmental-related decisions and for the evaluation of product quality in industries [7].…”

Preparation of Secondary pH of Phthalate Buffer Solution Using Differential Potentiometric Cell: Method Validation and Application

“…Practically, the pH is used to specify acidity or basicity properties of any substance that are mainly in the form of their aqueous solution. Determination of pH is one of the most common and frequent quantitative measurement in the field of chemical analyzes [2]. The common application of the pH measurement is to control industrial processes with the purposes to preserve product quality, reduce the corrosion rate in plant equipment, and protect the aqueous environment by helping wastewater discharge process to meet regulatory limits [3].…”

“…A reliable data of a pH measurement process having a traceability property to the International System of Units (SI) is extremely required [2]. For pH measurement, the traceability chain can be established by linking the pH data resulted from a measurement to the pH value of a primary pH buffer standard solution [6].…”