pH, ions, DO, conductivity applications
Measuring concentrations with sensors is one of the simplests analytical methods available. Our experts have compiled numerous application documents on pH, ions, dissolved oxygen, and conductivity measurements of various samples.
Use the filters to search the applications by analyte/parameter, sample matrix, norm, or industry.
- AN-I-036Sodium content in water using an ion-selective electrode
Groundwater contains many minerals, but can be contaminated by sodium-rich leachate from landfills. Accurate Na determination in water is possible following AOAC 976.25 using the Na-ISE.
- AN-I-035Sodium content in food using an ion-selective electrode
Excess sodium intake increases the risk of health issues. Ion-selective electrodes (ISEs) offer a fast, accurate, and cost-effective method for measuring sodium in food.
- AN-T-235Determination of pH in carbon black
The pH value in carbon black, an essential additive in modern lithium-ion batteries, is accurately and reliably analyzed in this Application Note by using the 913 pH Meter equipped with a Unitrode easyClean according to ASTM D1512 as well as ISO 787-9 and GB/T 1717-1986.
- TA-066Webinars: pH Measurement Made Easy
Even though pH measurement is one of the most often used analytical methods in chemistry and is considered rather simple to perform, several factors have to be taken into account to obtain accurate and precise measuring results. The accompanying article for the two webinars on pH measurement summarizes the most important points. In the first part of the webinar the focus lies on the basics of pH measurement. It gives further insights on which parameters have a direct influence on pH measurement and how to control them as well as electrode selection, maintenance and storage. The second part of the webinar targets troubleshooting of common errors, and tips and tricks for a correct pH measurement in matrices other than simple aqueous solutions.
- AN-I-034Investigation of nucleation processes with automated titrators
This Application Note covers the formation of calcium carbonate from solution.
- AN-T-076Conductivity, pH value, alkalinity, hardness, and chloride in tap water
In this application note, a fully automated system is presented which allows the determination of several parameters according to various standards within one analysis. These include conductivity (ISO 7888, EN 27888, ASTM D1125, EPA 120.1), pH value (EN ISO 10523, ASTM D1293, EPA 150.1), alkalinity (EN ISO 9963, ASTM D1067, EPA 310.1), Ca/Mg (ISO 6059, ASTM D1126, EPA 130.2), and chloride (ISO 9297, ASTM D512, EPA 325.3). Additionally the system transfers the required volume of sample into external titration vessels for the different analyses, reducing manual sample preparation. Furthermore, all sensors can be automatically calibrated and the titer of each titrant can also be determined.
- AN-T-219pH value and TTA in flour, dough, and bread
In order to consistently manufacture high quality baked goods, it is critical to measure the pH value and acidity content in the raw materials and during the production steps. These factors have a major influence on the taste and storage lifetime of the final product. Consistent product quality is only possible with precise measurements during the process. This Application Note describes the measurement of pH value and the total titratable acidity in flour, dough, and bread using the Eco Titrator from Metrohm.
- AN-T-211Fully automated wine analysis – Determination of free and total sulfurous acid, reductants, total acidity and pH value according to OIV
The analysis of the reductants, free and total sulfurous acid, pH and total acidity of wine can be performed fully automated on an OMNIS system based on the directive OIV-MA-AS323-04B, OIV-MA-AS313-01 and OIV-MA-AS313-15. Added components like SO2 have preserving properties and affect the microbiological environment (anti-microbacterial and enzyme-deactivating), they trap fermentation byproducts such as acetaldehyde and suppress a coloring into brown. The bound and free sulfurous acid are in an equilibrium with each other and can be determined via iodometric titration. Iodometric titration is also the method of choice to quantify other reductants, such as dyes, tanning agents, degradation products of carbohydrates and ascorbic acid. Finally, the acidity of wine is an important quality parameter, which affects the color and taste of wines. The total acidity and the pH of wine can be determined on the same system. Hence, Metrohm offers an all-in-one solution for the analysis of these mentioned key parameters.
- AN-T-209Electrical conductivity in ethanol, bio-ethanol, and biofuel – Fast and easy conductivity measurement according to DIN 15938
Ethanol, bio-ethanol and biofuel (E85) are increasingly used as substitutes for petroleum-based fuels. During storage, they often come into contact with metallic substrates or surfaces, e.g., in barrels, tanks, or other containers. Excessive concentrations of ions in the stored fuel promotes corrosion. Monitoring the total concentration of the ions present in the fuel matrix should be the first step of an effective anti-corrosion strategy. An easy, fast, and cost-effective method to determine the total amount of ions is by measuring the electrical conductivity according to DIN 15938.
- AN-T-205Fully automated water analysis by OMNIS
The determination of the physical and chemical parameters as electrical conductivity, pH value, alkalinity, the calcium and magnesium hardness as well as the total hardness are necessary for evaluating the water quality. A fast and accurate determination in tap water is realized using an automated OMNIS System working in parallel on different workstations. An 856 Conductivity Module with Dosinos extends the system.