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Following the addition of caustic soda, hexafluorosilic acid can be determined through back titration of excess hydroxide with hydrochloric acid. Hydrofluoric acid (hydrogen fluoride) is determined by precipitation with aluminum in the presence of sodium and potassium ions. Nitric acid is determined by subtracting the equivalence concentrations of hexafluorosilic acid and hydrofluoric acid from the total acid concentration.

Nitric acid, phosphoric acid, and acetic acid are easily determined in etching baths using thermometric titration (TET). Compared to potentiometric titration, TET is faster and more convenient. Analysis is complete in less than two minutes.

Thermometric titration can determine the total acid number (TAN) of various crude oil products according to ASTM D8045 without requiring any sensor maintenance.

Metal-organic compounds are commonly used in organic chemistry, for example as Grignard reagents or as strong bases (e.g., butyl lithium compounds). The knowledge of the exact content of reactive species allows to better plan the required amounts for reactions preventing the waste of material or too low yields. This Application Note describes the analysis of metal organics by thermometric titration using 2-butanol as titrant. Due to the strongly exothermic nature of the reaction between 2-butanol with metal-organic compounds, a fast and quantitative analysis of these substances is possible.

Tartaric Sulfuric Anodizing (TSA) is an established technique for corrosion protection in the aerospace industry. It is an alternative to the environmentally harmful chromic anodizing process. As such, a method to monitor the levels of sulfuric acid and tartaric acid in TSA plating baths is required. Potentiometric titration methods have been developed, and are widely used across the industry. Their disadvantage is that two titrations with different electrodes and solvents are required. In this Application Note, an alternative method is presented, where the concentration of both acids is determined in sequence using a thermometric sensor. Compared to potentiometric titration, thermometric titration is faster and more convenient (no sensor maintenance required). On a fully automated system, the determination of both parameters takes about 7 minutes.

Iron sucrose injections are used during the treatment of iron deficiency anemia. They contain a mixture of ferric iron (Fe3+) and ferrous iron (Fe2+). Ferrous iron content may be determined by subtracting the ferric iron content from the total determined iron content. Yet, this increases the measurement error due to error propagation. Alternative determination of iron(II) with cerium(IV) by potentiometric titration may be hampered, as the equivalence point cannot be determined unequivocally. Determination by thermometric titration is a more robust and therefore more reliable alternative, as this method is unaffected by the sample matrix. Here, the endpoint of the titration is indicated by a fast responding thermometric sensor. Endpoint detection is further improved by spiking the sample with 0.2% ammonium iron(II) sulfate (FAS), increasing the reliability of the determination. Compared to potentiometric titration, thermometric titration is faster and more convenient as no sensor maintenance is required. One determination takes about 2–3 minutes.

Sulfur is a secondary macronutrient for plants and is essential for chloroplast growth and function. In fertilizers, sulfur is usually provided in the form of sulfate. Traditionally the sulfate content is determined gravimetrically by precipitation with barium. The drawback of this method is that it requires numerous time consuming and laborious analysis steps. In this Application Note, an alternative method is presented, where sulfate is determined by a precipitation titration with barium chloride. Various solid and liquid NPK fertilizers with sulfur contents between 1 and 8% were analyzed. The analysis of sulfate in fertilizers by thermometric titration requires no sample preparation at all for liquid NPK fertilizers, and only minimal sample preparation for solid NPK fertilizers. One determination takes about 3 minutes only. To increase the sensitivity of the method, the samples are spiked with a standard sulfuric acid solution, which is then considered when calculating the result.

Fertilizers are applied in the agricultural sector to provide more essential nutrients to growing plants. The so-called «NPK» fertilizers provide such nutrients to plants with its three main components (N – nitrogen, P – phosphorous, K – potassium). In fertilizers, nitrogen is mainly provided in three forms: as ammonium nitrate (NH4NO3), ammonia (NH3), and urea (H2NCONH2). Determination of the individual nitrogen-contributing components is often laborious work. Thermometric titration offers the possibility to rapidly determine the amount of ammoniacal nitrogen and urea nitrogen in a single titration using sodium hypochlorite as titrant.

Potassium is a primary macronutrient for plants, as it plays an important role in water regulation as well as plant growth. In NPK fertilizers, potassium is present besides nitrogen and phosphorus, which are the other two primary macronutrients. Knowing the quality and content of a NPK fertilizer allows an optimal fertilizer management for a planned culture, saving costs and increasing profitability. Traditionally potassium is determined gravimetrically or by flame photometry. In this Application Note, an alternative method is presented, where potassium is determined a precipitation titration. Various solid and liquid NPK fertilizers with potassium contents between 10 and 27% were analyzed. After the removal of any present ammonia, the potassium can be determined reliably in about 5 minutes.

Potash is commonly mined from ore, deposited after ancient inland oceans evaporated. The potassium salt is then purified in evaporation ponds. At the end of this process, the potash is typically obtained as potassium chloride. Potash is mainly used as fertilizer, providing potassium—an essential nutrient—to plants. Additionally, it is used in the chemical industry and to produce medicine. Potassium content in potash is typically determined by flame photometry (F-AES) or ICP-OES. However, these techniques have high investment and running costs. By applying the historically used gravimetric precipitation reaction as a thermometric titration, it becomes possible to rapidly and inexpensively determine the potassium content in potash within minutes.