Application Finder
- AN-H-096Determination of total base number of lubricating oils
Dissolution of oil in toluene, and titration with standard 0.1 mol/L trifluoromethanesulfonic acid in acetic acid using isobutyl vinyl ether as a thermometric endpoint indicator.
- AN-H-097Determination of calcium and magnesium in harvested salt
A measured amount of salt is titrated directly with a solution of 1 mol/L tetrasodium EDTA to thermometrically determined endpoints for Ca and Mg. Acetylacetone is added to alter the Ca and Mg EDTA stability constants for better endpoint sharpness.
- AN-H-098Determination of hydrofluoric acid in silicon etch solutions
This Application Note describes the determination of fluoride in silicon etch solutions with thermometric titration.
- AN-H-099Determination of potassium hydroxide and silica in alkaline etch solutions
Determination of concentrated potassium hydroxide solutions which had been used for the etching of substrates containing silicon.
- AN-H-100Determination of total acids in highly acidic etch solutions
Determination of the total acids concentration in mixtures of nitric-hydrofluoric acid intended for etching silicon substrates.
- AN-H-101Determination of the water content of mineral acids
A sample of concentrated mineral acid is dissolved in anhydrous acetonitrile, and the water content titrated with a solution of TEOF in acetonitrile. The TEOF reacts exothermically with water in the presence of a strong acid (acting as a catalyst).
- AN-H-102Determination of Hypochlorite by Titration with Ammonium Ion
Hypochlorite ions react with bromide ions to form hypobromite ions, which in turn rapidly oxidize ammonium ions to nitrogen. Hypobromite reacts more rapidly with ammonium than hypochlorite, and is formed in situ (Vogel, 1961). The titration is carried out with in a solution containing bromide and bicarbonate.
- AN-H-103Determination of Calcium and Magnesium in Milk
A measured amount of milk is treated with trichloroacetic acid to coagulate milk solids and liberate calcium and magnesium as dissociated ion. The coagulated milk is filtered or centrifuged, and an aliquot of the clear serum is titrated with a standard solution of 1 mol/L tetra-sodium EDTA to thermometrically determined endpoints for Ca and Mg. Acetylacetone is added to alter the Ca- and Mg- EDTA stability constants for better endpoint sharpness.
- AN-H-104Determination of free acid content of hydrometallurgical leach liquors
A measured amount of acidic hydrometallurgical leach liquor is treated with potassium oxalate solution to mask potential interference from Fe(III) and other metal ions, and then titrated with standard 1 mol/L NaOH solution.
- AN-H-105Determination of nickel in hydrometallurgical leach liquors
A measured amount of acidic hydrometallurgical leach liquor is first treated with hydrogen peroxide to oxidize Fe(II) to Fe(III), then with potassium pyrophosphate solution to mask interference from Fe(III) and other metal ions. Ammonium acetate solution is then added as a pH modifier, before being titrated with standardized disodium dimethylglyoximate to an exothermic endpoint.
- AN-H-106Determination of magnesium content in hydrometallurgical leach liquors
A measured amount of acidic hydrometallurgical leach liquor is treated first with a complexing agent (sodium gluconate). It is then basified to ~pH 10.5 with a NH3 /NH4Cl buffer, prior to the addition of KCN solution to mask Fe(III). Caution! Do not add KCN to solutions of pH below 9! The Fe(III) is then reduced to Fe(II) by additon of ascorbic acid, prior to titrating the Mg content with standard Na4EDTA solution.
- AN-H-107Determination of ferrous ion content in hydrometallurgical leach liquors
A measured amount of acidic hydrometallurgical leach liquor is further acidified with sulfuric acid, prior to being titrated with standard potassium dichromate solution to an exothermic endpoint. Thus, 1 mol K2Cr207 ≡ 6 mol Fe2+.
- AN-H-108Determination of ferric ion in hydrometallurgical leach liquors
A measured amount of acidic hydrometallurgical leach liquor is pH modified with a small amount of glacial acetic acid, and the Fe(III) content reduced to Fe(II) with iodide ion. The liberated iodine is titrated with standard thiosulfate solution to an exothermic endpoint. Thus, 1 mol Fe3+= 1 mol S2O32-.
- AN-H-109Determination of sulfuric acid, hydrofluoric acid, and ammonium bifluoride in acid mixtures
Results from three separate single endpoint titrations are used to calculate the results. The mixture of H2SO4, HF, and NH4F/HF contains H+ from H2SO4, HF, and NH4F/HF, SO42- from H2SO4, and F- from HF and NH4F/HF. Analysis of total H+ («total acids») by NaOH titration, F- by titrating with Al(NO3)3 («total fluoride») and SO42- by titrating with BaCl2 provides the information required to determine the composition of the mixture.
- AN-H-110Determination of sulfate in drinking water by barium chromate displacement
Sulfate is precipitated by reaction with an acidified barium chromate solution. The excess barium chromate is precipitated by basification with ammonia solution. Residual soluble chromate equivalent to the sulfate content of the sample is titrated with a solution of standard ferrous ion to a thermometrically determined endpoint.
- AN-H-111Determination of sulfate in harvested salt
Sulfate is precipitated as barium sulfate by reaction with an acidified barium chromate solution. The excess barium chromate is precipitated by basification with ammonia solution. Residual soluble chromate, equivalent to the sulfate content of the sample, is titrated with a solution of standard ferrous ion to a thermometrically determined endpoint.
- AN-H-112Determination of total sodium in commercial cheeses by thermometric titration
Samples of shredded, grated, or sliced cheese are dispersed with a high-speed disintegrator in a solution of trichloroacetic acid, which denatures protein and assists in the liberation of all sodium from the matrix. Toluene is added in a second step of the dispersion process to assist in the solubilization of fat. Ammonium fluoride solution is then added, and the sodium titrated with a titrant comprising 0.5 mol/L Al(NO3)3 and 1.1 mol/L KNO3 to an exothermic endpoint.Na+ + 2K+ + Al3+ + 6F- ↔ NaK2AlF6 ↓In this determination, ammonium fluoride (NH4F) has been found to give sharper endpoints than ammonium bifluoride (NH4F ∙HF). In addition to this application note, you can find more information on thermometric sodium determination in foods in our application video available on YouTube:https://youtu.be/lnCp9jBxoEs
- AN-H-114Determination of sulfuric acid, nitric acid, and hydrofluoric acid in etch solutions
Two separate titration sequences are required to analyze the mixture:- titration of the HF content with Al(NO3)3 (the «elpasolite» reaction)- titration of the H2SO4 with BaCl2 followed by titration with NaOH to determine the «total acids» contentThe HF, H2SO4, and «total acids» contents are converted to a HNO3 equivalent, with the HNO3 content found by subtracting the HF and H2SO4 from the «total acids» content.
- AN-H-115Determination of hydrofluoric acid, ammonium fluoride, and maleic acid in acid cleaning solutions
A direct thermometric titration (TET) with 2 mol/L NaOH is used to determine the HF, NH4F, and maleic acid (C4H4O4) contents of acid cleaning solutions. Three endpoints (EPs) are obtained, which may be assigned as follows:EP1: C4H4O4 (pKa1 = 1.9), HF (pKa = 3.17)EP2: C4H4O4 (pKa2 = 6.07)EP2: NH4F (pKa = 8.2)The HF content is determined by subtracting the difference (EP2-EP1) from EP1.
- AN-H-116Determination of sulfate in phosphoric acid through the standard addition of sulfuric acid
This Application Note supplements AN-H-003 with the treatment of the standard addition of sulfate as sulfuric acid. This technique may be contemplated when either sulfate levels are too low for a satisfactory direct titration, or when the sample matrix hinders endpoint detection, leading to poor precision and accuracy.
- AN-H-117Rapid determination of hydroxide and aluminum oxide in aluminate liquors
This Application Note describes the determination of the free and total hydroxide and aluminum oxide content in Bayer process and other aluminate liquors. The method is not subject to interference by carbonate ions. An aliquot of sodium aluminate liquor is titrated with potassium hydrogen carbonate solution to yield the free hydroxide ion content of the liquor.
- AN-H-118Determination of hydrochloric acid in acidic solutions containing iron and aluminum
The presence of the hydrated ion [Fe(H2O)6]3+ can interfere with the determination of «free acid» due to the low pKa value (~2.2) of this ion. Ions of metals such as Fe, Cu, and Al can be masked effectively with fluoride, and permit the determination of the acid content by thermometric alkalimetric titration with good accuracy and precision.
- AN-H-119Determination of ferric ion in acidic solutions
This Application Note deals with the determination of ferric ion in acidic and copper-free solutions using thermometric titration. The ferric ion is reduced by iodide. The released iodine reacts exothermically when titrated with thiosulfate solution. The endpoint is determined through temperature plotting by the temperature sensor Thermoprobe.
- AN-H-120Determination of aluminum ion in acidic solutions containing ferric and ferrous ions
This Application Note describes the determination of aluminum ion down to approximately 0.5 g/L in acidic solutions containing ferric, ferrous, and other ions whose hydroxides do not dissolve in strongly basic solutions.
- AN-H-121Determination of ferrous ion in acidic solutions with ceric solution
This Application Note looks at the determination of ferrous ion in acidic solutions from approximately 0.25 g/L by thermometric titration with ceric titrant. The exothermic oxidation reaction shows a sharp endpoint that is detected using the Thermoprobe as a sensitive temperature sensor.
- AN-H-122Determination of sodium in canned fish products
This Application Note describes the determination of total sodium content in canned fish products using thermometric titration. In addition to this application note, you can find more information on thermometric sodium determination in foods in our application video available on YouTube:https://youtu.be/lnCp9jBxoEs
- AN-H-123Determination of sodium in instant noodles
This Application Note describes the determination of the total sodium content in instant noodles which are also called «two minute noodles» in some countries. These products contain considerable amounts of sodium (at least 50% of the recommended daily dosage), which means that precise analysis of the sodium content is required. Argentometric titration of the chloride content (assuming that the sodium content in the noodles originates exclusively from the sodium chloride that is added to them) is unsuitable for precise analysis, as the nutrient contents listed on the product packaging document the presence of additional sodium salts other than sodium chloride. Thermometric titration enables fast and direct determination of sodium. In addition to this application note, you can find more information on thermometric sodium determination in foods in our application video available on YouTube:https://youtu.be/lnCp9jBxoEs
- AN-H-124Determination of sodium content in the manufacturing of margarine
This Application Note describes the determination of the total concentration of sodium in precursor solutions used in the manufacturing of margarine. The solutions of the precursors are mixed with edible fats and oils to make margarine. Traces of sodium chloride and other sodium and potassium salts may be added to the margarine during this process, usually in the form of emulsifiers, stabilizers, antioxidants, vitamins, coloring agents or flavor enhancers. The analysis of the total sodium content in the precursor solutions is more efficient and cost-effective for the manufacturers than later total sodium content analyses in the final product.As a rule, argentometric titration of chloride is used for indirect determination of the sodium content of foodstuffs. The assumption behind this approach is that the chloride ions are present in a molar ratio of 1:1 with the sodium ions. This is however not the case when – as is usually the case with foodstuffs containing sodium – additional compounds containing sodium are also present in the margarine. The use of potassium chloride as a partial replacement for sodium chloride in some formulations is an additional source of error.The direct titration of sodium by means of thermometric endpoint titration (TET) eliminates these problems. TET is a direct determination method that not only takes into account the entire sodium content present in the solution but is also not hampered by the presence of potassium ions. In addition to this application note, you can find more information on thermometric sodium determination in foods in our application video available on YouTube:https://youtu.be/lnCp9jBxoEs
- AN-H-125Determination of sodium in soy milk
This application note describes the determination of the total sodium content in soy milk products. The methodology may also be applied to the determination of sodium in milk products from cows, goats and sheep. A standard addition technique is employed to permit the accurate and precise determination of sodium at relatively low levels.
- AN-H-126Determination of silver and nitric acid in silver electrolyte bath
Silver and nitric acid are determined in silver electrolyte solutions by means of thermometric titration. The method provides accurate results in a short time and is ideally suited for routine process control.
- AN-H-127Thermometric analysis of aluminum by back-titration
This Application Note describes the determination of aluminum in samples containing silicon dioxide using thermometric titration and EDTA as the titrant. Excess EDTA is titrated with a Cu2+ solution of known concentration. The initial, uncomplexed Cu2+ ions react immediately with the H2O2 present in the solution, leading to a recognizable sudden increase in temperature.
- AN-H-128Determination of ferrous ion in acidic solutions with permanganate as titrant
This Application Note looks at the determination of ferrous ion in acidic solutions through redox titration with potassium permanganate as titrant and thermometric titration.
- AN-H-129Determination of weak bases in nonaqueous media through catalyzed thermometric endpoint titration (CETT)
Weak, organic bases that are soluble in nonaqueous solvents (including nonpolar solvents) are determined in glacial acetic acid using titration with strong acids, e. g., anhydrous perchloric acid or trifluoromethanesulfonic acid. The endpoint of such titrations can be determined thermometrically, insofar as a suitable thermometric endpoint indicator exists. The exceptional suitability of isobutyl vinyl ether (IBVE) as indicator has been demonstrated.
- AN-H-130Determination of nitrite using sulfamic acid
This Application Note describes the determination of nitrite using thermometric endpoint titration with sulfamic acid. The nitrite content of a solution can be analyzed down to 0.2 mmol/L.
- AN-H-131Determination of titer and blank value for thermometric titrations using tiamo™
This Application Note describes in detail how to determine the blank value and the titer for thermometric titrations using tiamo™.
- AN-H-132Thermometric endpoint titration of hydrogen peroxide with iodometry
Hydrogen peroxide solutions can be determined through thermometric endpoint titration (TET) using iodometry. Iodide is oxidized to become iodine, which is then titrated with a standard thiosulfate solution in an exothermic reaction.
- AN-H-133Automatic sodium determination in cheese
Sodium can be determined thermometrically in cheese without sample preparation and addition of additives. A homogenizer is responsible for distribution and stirring. In addition to this application note, you can find more information on thermometric sodium determination in foods in our application video available on YouTube:https://youtu.be/lnCp9jBxoEs
- AN-H-134Determination of sulfuric acid and phosphoric acid in etching baths using thermometric titration
Thermometric titration can be used for the ready determination of sulfuric acid and phosphoric acid in acid mixtures. An endpoint for each acid appears on the titration curve that can be used to quantify the respective acid.
- AN-H-135Determination of hydrochloric acid and phosphoric acid in etching baths using thermometric titration
Thermometric titration is used for the determination of hydrochloric acid and phosphoric acid in acid mixtures. Two endpoints appear on the titration curve that are used for the determination of the two acids.
- AN-H-136Determination of hydrochloric acid and nitric acid in etching baths using thermometric titration
Thermometric titration is used for the determination of hydrochloric acid and nitric acid in acid baths. The entire acid content is titrated with caustic soda in the initial titration; the hydrochloric acid content is then determined in a second titration using silver nitrate solution.
- AN-H-137Determination of hydrochloric acid and hydrofluoric acid in etching baths using thermometric titration
Thermometric titration is used to determine hydrochloric acid and hydrofluoric acid (hydrogen fluoride) in etching baths containing ethanol and acetonitrile. Two endpoints appear on the titration curve that are used individually for the quantification of the respective acid.
- AN-H-138Determination of nitric acid and hydrofluoric acid in etching baths using thermometric titration
Thermometric titration is used to determine hydrofluoric acid and nitric acid in etching baths containing ethanol and acetonitrile. Two endpoints appear on the titration curve that are used individually for the quantification of the respective acid.
- AN-H-139Determination of nitric acid, hydrofluoric acid and hexafluorosilic acid in simulated etching baths using thermometric titration
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.
- AN-H-140Titration of phosphoric, nitric, and acetic acid mixtures
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.
- AN-H-141Acid number in crude oil and gas oil according to ASTM D8045
Thermometric titration can determine the total acid number (TAN) of various crude oil products according to ASTM D8045 without requiring any sensor maintenance.
- AN-H-142Determination of metal-organic compounds
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.
- AN-H-143Sulfuric acid and tartaric acid in tartaric sulfuric anodizing bath – Rapid, sequential determination using a thermometric sensor (thermometric titration)
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.
- AN-H-144Ferrous iron in iron sucrose injection
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.
- AN-H-145Sulfate in fertilizers – Rapid and reliable determination by thermometric titration
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.
- AN-H-146Ammonium and urea nitrogen in NPK fertilizers
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.
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