Applications relatives au pH, aux ions, à l'OD et à la conductivité
La mesure des concentrations à l'aide de capteurs est l'une des méthodes analytiques les plus simples qui soient. Nos experts ont compilé de nombreux documents d'application sur les mesures de pH, d'ions, d'oxygène dissous et de conductivité de divers échantillons.
Utilisez les filtres pour rechercher les applications par analyte/paramètre, matrice d'échantillon, norme ou industrie.
- AN-T-235Détermination du pH dans le noir de carbone
La valeur du pH dans le noir de carbone, un additif essentiel dans les batteries lithium-ion modernes, est analysée de manière précise et fiable dans cette note d'application en utilisant le pH-mètre 913 équipé d'un Unitrode easyClean conformément à l'ASTM D1512 ainsi qu'à l'ISO 787-9 et au GB/T 1717-1986.
- AB-082Détermination du fluorure à l'aide d'une électrode ionique spécifique
Ce Bulletin décrit la détermination du fluorure dans diverses matrices à l'aide de l'électrode ionique spécifique au fluorure (F-EIS). L'électrode F-EIS se compose d'un cristal de fluorure de lanthane et présente un comportement de Nernst sur une grande plage de concentration de fluorure.La première partie de ce Bulletin contient des informations sur la manipulation et l'entretien de l'électrode ainsi que la détermination du fluorure proprement dite. La deuxième partie démontre la détermination directe du fluorure par la technique d'addition de standard dans le sel de cuisine, le dentifrice et les bains de bouche.
- AN-I-032Dissolved oxygen, conductivity, and pH value in liquid dairy products
In the food industry, it is essential to determine and monitor certain quality parameters to guarantee consistency. This is especially important for liquid dairy products, which are subject to a strict cold chain. Both the dissolved oxygen (DO) and the pH value have proven to be reliable quality criteria. Oxygen shortens the shelf life and influences the product quality (e.g., nutritional value, color, and flavor). The DO content depends on the salinity in the sample, which is automatically calculated and corrected by the 914 pH/DO/Conductometer during the parallel conductivity measurement. Acidity is another important characteristic to measure that can be checked easily using the pH value. With the 914 pH/DO/Conductometer, all important quality criteria can be monitored with one device.
- AN-I-013Sulfide in ground and waste water
Even in low concentration, sulfide ions cause odor and corrosion problems in ground water and waste water. They can release hydrogen sulfide in acidified water, which is toxic in even minuscule amounts. This Application Note describes the determination of sulfide concentration in water via direct measurement with the Ag/S-ISE in accordance with ASTM D4658.
- AN-I-014Bromide in water
Bromide is ubiquitous in sea water, where it is present in concentrations of around 65 mg/L. By contrast, the maximum bromide concentration in drinking and ground water is usually less than 0.5 mg/L. A higher bromide content may indicate a contamination of the water caused by fertilizer, road salt or industrial waste water. This Application Note describes the determination of the bromide content in water via direct measurement with a Br ion-selective electrode in accordance with ASTM D1246.
- AN-I-023Fluoride in tea
One of the major sources of fluoride intake for humans comes from foodstuff, such as tea. Tea actually has one of the highest potentials to increase the daily fluoride intake. Excessive fluoride intake may lead to dental or skeletal fluorosis. The World Health Organization does not recommend consuming water with a fluoride content higher than 1.5 mg/L. In the presented method according to DIN 10807, the fluoride content can be assessed quickly with an ion selective electrode.
- AN-I-009Cyanide in water
Cyanides are used in some industrial processes, but if not handled carefully, they could contaminate the wastewater. In an acidic or neutral environment, this contaminated wastewater can form highly toxic hydrogen cyanide gas. Furthermore, the cyanide salts could also poison the environment and enter the ground water system. Therefore, it is essential to monitor the content of cyanide in effluent water. Cyanides can be easily determined with a cyanide ion-selective electrode. This application note presents a method for cyanide analysis according to APHA Method 4500-CN and ASTM D2036.
- AN-I-027Dissolved oxygen in fruit juices
Dissolved oxygen (DO), incorporated into juices during processing, affects quality parameters of the beverage during storage such as Vitamin C concentration, color, and aroma. Various oxygen removal methods are used during juice production, such as vacuum-deaeration or gas sparging to increase product quality and extend shelf life. However, these methods have the drawback that the aroma might be affected since the volatile compounds are also removed. By assessing the DO content in fruit juices, manufacturers can improve the overall product quality. This application note describes a fast and accurate determination of dissolved oxygen in juices by using an optical sensor.
- AN-I-028Dissolved oxygen in surface water
Oxygen diffuses into water sources from the air via aeration, however several factors can reduce the dissolved oxygen (DO) content in water. First, as water warms up, oxygen is released into the atmosphere. Secondly, oxygen is consumed by bacteria and other microorganisms which feed on organic material. Finally, plants can also consume oxygen in certain situations.Human-induced alterations can have a negative influence on surface water when DO values fall below crucial limits for maintaining the life supporting capacity of freshwater ecosystems. Therefore, monitoring the DO content in surface water by an optical sensor to assess its quality is important.
- AN-I-030Oxygène dissous dans l'eau du robinet
Dans les approvisionnements en eau des municipalités, une teneur élevée en oxygène dissous (OD) est souhaitable car elle améliore le goût de l'eau potable. Cependant, les niveaux élevés d'OD accélèrent également la corrosion dans les conduites d'eau. C'est pourquoi les industries utilisent de l'eau contenant le moins d'oxygène possible et ajoutent des épurateurs tels que le sulfite de sodium pour éliminer tout oxygène de l'approvisionnement en eau. Les conduites d'eau municipales sont normalement recouvertes à l'intérieur de polyphosphates pour protéger le métal du contact avec l'oxygène, ce qui permet des teneurs en OD plus élevées. Par conséquent, il est important de surveiller en ligne la teneur en OD d'un approvisionnement en eau afin d'évaluer sa teneur en OD pour améliorer le goût ou minimiser la corrosion des tuyaux. L'utilisation d'un capteur optique, tel que l'O-Lumitrode, permet une détermination rapide et fiable conformément à la norme ISO 17289.
