Aplikasi: Distilasi Uap

Comparison boric acid vs. back titration

Ammonium, nitrate, and total nitrogen determination in fly ash

Fly-ash is a by-product of the combustion of pulverized coal and is composed of small particles. Nowadays, air pollution control standards require a separation of flue gas before being released to the atmosphere.The composition of the fly ash may vary considerabley, however, all fly ashed contain substantial amounts of silicon dioxide (SiO2) aluminium oxide (Al2O3) and calcium oxide (CaO). The fly ash in this study was provided from a pulp mill containing organic and inorganic (ammonium nitrate and ammonium sulfate) nitrogen compounds.

Total SO2 content determination in shrimp paste by modified Monnier-Williams Method

Total SO2 is defined as “the total of all the various forms of sulfur dioxide present in the sample, either in the free state or combined with their constituents”. Its determination in solid samples poses a challenge because SO2 is withheld in adducts and is released slowly during boiling. Recognized results are obtained by means of the generally accepted Optimized Monier-Williams method according to AOAC 990.28 which suggests the use of nitrogen-assisted boiling of the acidified sample to release the Total SO2. The method presented in this study provides equally quantitative results with much less time required per sample and is based on steam distillation followed by pH titration.

In this application note recovery results for a widely used reference standard HMS, and a certified sample of shrimp paste (41±9.7ppm) for total sulfite analysis are presented. A representative concentration of 1 mg SO2 /sample tube is selected to demonstrate the robust performance of modified Monier-Williams method by steam distillation. 

TKN determination in water and wastewater

An easy and reliable method for the determination of Total Kjeldahl Nitrogen (TKN) in water and wastewater, according to ISO 5663, DIN EN 25 663 and the methods listed in 40 CFR part 136.3, is introduced below. In this study, the limit of detection (LOD) and limit of quantification (LOQ) which is a measure of sentisivity of a method, were determined. To test the performance, nitrogen recovery in different concentrations of urea solutions was tested. The samples are digested using the SpeedDigester K-439 using Kjeldahl Tablets Titanium. A steam distillation protocol followed bya suitable boric acid titration is performed with the MultiKjel together with the Metrohm Eco Titrator. Coupling the new MultiKjel system and the Eco Titrator results in excellent performance with ease and speed of the analysis.

Total SO2 content determination in reference standards by BUCHI method

Sulfites are widely used as preservatives and antioxidants in foods and beverages. Exposure to high levels of sulfites can cause an allergic reaction. Given the health risks associated with sulfite exposure, its amount in beverages and foods is regulated in many countries. Regulations have set the maximum amount of sulfites used and required labelling practice to indicate the presence of sulfites. Total SO2 is defined as “the total of all the various forms of sulfur dioxide present in the sample, either in the free state or combined with their constituents”. Its determination in solid samples poses a challenge because SO2 is withheld in adducts and is released slowly during boiling. Recognized results are obtained by means of the generally accepted Optimized Monier-William’s method according to AOAC 990.28 which suggests the use of nitrogen-assisted boiling of the acidified sample to release the Total SO2. The method presented in this study provides equally quantitative results with much less time required per sample and is based on the patented BUCHI Method that involves steam distillation followed by a redox titration.

TKN determination in water and waste water using potentiometric titration

An easy, reliable and high troughpout method for the determination of Total Kjeldahl Nitrogen (TKN) in water and waste water, according to ISO 5663, DIN EN 25 663 and the methods listed in 40 CFR part 136.3, is presented. In this study, the Limit of Detection and Limit of Quantification, which are a benchmark for the method’s sensitivity, were determined for water samples. To test the system’s performance, the nitrogen recovery of different concentrations of a urea reference sample was tested.  The samples were digested mercury and selenium free using the KjelDigester K-449. The distillation and potentiometric boric acid titration were performed with the KjelMaster K-375 with KjelSampler K-376.

Sulfur dioxide determination in wine by BUCHI SO2 method

Penetapan TKN dalam air dan air limbah

Penetapan TKN (Total Kjeldahl Nitrogen) dalam air dan air limbah adalah prosedur rutin untuk penjaminan mutu dan inspeksi. Dalam dokumen ini, diperkenalkan prosedur yang andal untuk penetapan TKN dalam air, sesuai dengan ISO 5663, AOAC 973.48, dan 40 CFR 136.3.

Total sulfur dioxide determination in dried apricots by BUCHI method

Sulfites are widely used as preservatives and antioxidants in foods and beverages. Exposure to high levels of sulfites can cause an allergic reaction. Given the health risks associated with sulfite exposure, its amount in beverages and foods is regulated in many countries. Regulations have set the maximum amount of sulfites used and required labelling practice to indicate the presence of sulfites. A typical application of food preservation with sulfites is in dried fruit like dried apricots. For this reason, a reference sample of dried apricot mousse with a certified total SO2 content and a sample without any sulfite treatment were analysed for Total SO2 in this study.

Total Kjeldahl Nitrogen determination in wastewater

Total sulfur dioxide determination in dried apricots by modified Monnier-Williams method

Sulfites are widely used as a preservative and antioxidant in foods and beverages. Exposure to high levels of sulfites can cause an allergic reaction. Given the health risks associated with sulfite exposure, the amount in beverages and foods is regulated in many countries. Regulations set the maximum amount of sulfites used and required labelling practice to indicate the presence of sulfites. A typical application of food preservation with sulfites is in dried fruit like dried apricots. For this reason, a reference sample of dried apricot mousse with a certified total SO2 content and a sample without any sulfite treatment were measured for Total SO2 in this study.

Vicinal Diketones in Beer

Diacetyl (2,3-butanedione) and 2,3-pentanedione are vicinal diketones (VDK) which are formed during beer fermentation. VDK can have a significant effect on beer flavor, presence above their flavour threshold (approx. 0.1 mg/L for diacetyl and 1.0 mg/L for 2,3-pentanedione) can lead to butter/butterscotch like flavors that are undesired in most beer styles. The concentration of VDK depends on numerous process conditions, such as wort compostion, fermentation regime, yeast strain, but can also be caused by microbial contamination. The control of VDK levels during fermentation is an important aspect of quality control in a brewery. VDK can be determined by a variety of analytical methods. The usage of colorimetric assays, e.g., through complex formation with o-phenylenediamine and gas chromatography (GC) are most commom and recommended by the European Brewery Convention (EBC).

Uniform and dry SiO2 beads with the Encapsulator

Advanced ceramic materials are of high interest due to their specific and favorable properties such as hardness, durability, optical behavior compared to traditional materials. SiO2 among other oxides such as Al2O3, TiO2 and ZrO2, are common raw materials. In the manufacturing process of advanced materials, granulation is one of the important steps. Usually, large and uniform particles are desired.This application note describes the production of spherical and uniform SiO2 beads having an average size of approximately 430 μm in diameter. The Encapsulator B-395 Pro was applied to obtain and the Rotavapor® R-300 to dry the beads. Using the presented technique, the particle size of the final beads can be varied in the range between 300 and 1000 μm.

Protein determination in feed products using micro-Kjeldahl

Micro-Kjeldahl approach in dairy products

An easy and reliable method for the determination of the TKN content in dairy products is introduced. The samples are digested using the block digester KjelDigester K-449 with 300 mL Kjeldahl tubes following a "micro" approach, reducing used chemicals and consumables significantly and thus generating both ecological and economic advantages. A steam distillation protocol followed by a potentiometric boric acid titration is performed with the KjelMaste K-375 with KjelSampler K-376/K-377 in accordance with e.g. AOAC 991.20 and ISO 8968-2.

Micro-Kjeldahl: Protein determination in Dairy Products

An easy and reliable method for the determination of the Total Kjeldahl Nitrogen (TKN) and protein content in dairy products is introduced. The samples are digested using the SpeedDigester K-439 with 100 mL micro-Kjeldahl tubes. The steam distillation and titration in boric acid are performed with the MultiKjel in combination with a Metrohm Eco Titrator. This application note complies with official methods e.g. AOAC 991.20 and ISO 8968-2. Micro-Kjeldahl minimizes the amount of sulfuric acid and catalyst for the digestion, and the amount of sodium hydroxide for the distillation step as well. The savings in chemicals provides an economic and ecologic advantage to the classic Kjeldahl method while maintaining its high accuracy and preciseness.  

Protein determination in dairy products using a micro-Kjeldahl approach

An easy and reliable method for the determination of the Total Kjeldahl Nitrogen (TKN) and protein content in dairy products is introduced. The samples are digested using the SpeedDigester K-439 with standard 300 mL Kjeldahl tubes. The steam distillation and titration in boric acid are performed with the MultiKjel in combination with a Metrohm Eco Titrator. This application note complies with official methods e.g. AOAC 991.20 and ISO 8968-2. Micro-Kjeldahl minimizes the amount of sulfuric acid and catalyst for the digestion, and the amount of sodium hydroxide for the distillation step as well. The savings in chemicals provides an economic and ecologic advantage to the classic Kjeldahl method while maintaining its high accuracy and preciseness 

LOD/LOQ determination in colorimetric titration

LOD/LOQ determination in potentiometric titration

TKN determination in wastewater