Established in 1996, Concord Technology (Tianjin)Co., Ltd. is a manufacturer specialized in the research, development and production of high purity chemical reagents and pharmaceutical intermediates. Concord Technology (Tianjin) Co., Ltd. is a Chinese manufacturer of HPLC solvents and Karl Fischer Reagents. Our factory covering 25000 square meters is located in Tianjin with convenient transportation. The main export products are HPLC Acetonitrile, Methanol and Karl Fischer Reagents. The HPLC solvents annual output is 1500 tons and will be increased to 5000 tons in next year. Since we have obtained ISO9001:2008 Quality Management System Certificates and have high level R&D and QC team, we can supply you high quality products with competitive price and OEM.
Established in 1996. Concord Technology (Tianjin) Co., Ltd. is a manufacturer specialized in the research, development and production of high purity chemical reagents and pharmaceutical intermediates. We are located in Tianjin, with convenient transportation access. In 2003. we built the production base and the R & D center, covering 25000 square meters and having 6 production lines and over a hundred of varieties of products. The annual output of HPLC solvents is 1500 tons in 2011. We will have 2 large production lines next year to further improve the production capacity to 6000 tons per year. In order to supply the best products and services, we have built excellent teams which focus on product research & development and quality control & inspection. We have obtained GB/T19001-2000/ISO9001 2000 and ISO9001 2008 Quality Management System Certificates respectively. All of our products comply with international quality standards.
We have won some prizes during 15 years of development. We got Silver Prize for Science and Technology Progress in Tianjin City (Hebei District) in 1998 and were named as Excellent Private Science & Technology Enterprise of Tianjin City in 2004. Two of our products were entitled as Science and Technology Products of Tianjin City. By jointly carrying out the Key Projects in the National Science & Technology Support Plan in the 11th Five-year Plan Period since 2007. we have undertaken systematic research for three years on the preparation of high purity organic solvents and the common key technology for industrialization which was finally certificated by industry experts. Because of applying for 10 items of national patents and declaiming 4 items of science and technology achievements in 2009. our company was named as Advanced Unit for Intellectual Property.
We built a professional R&D team to research and produce pharmaceutical intermediates including series of boronic acids and derivatives compounds, pyridine compounds, heterocyclic compounds, benzene compounds, chiral compounds and some other compounds which are for the treatment of hepatitis C. hepatitis B drug, anti-infective drugs, diabetes and so on.
If you are interested in any of our products or would like to discuss a customized order, please feel free to contact us. We are looking forward to forming successful business relationships with new clients around the world in the near future.
- Core Values: Health, Science, Concord
- Teamwork: High Accuracy and Efficiency
- Target: Developing Technology. Pursuing Excellence
- Mission: Reliable High Purity Solvents Manufacturer
Karl Fischer titration is a classic titration method in analytical chemistry that uses coulometric or volumetric titration to determine trace amounts of water in a sample. It was invented in 1935 by the German chemist Karl Fischer.
The main compartment of the titration cell contains the anode solution plus the analyte. The anode solution consists of an alcohol
(ROH), a base (B), S02 and 12. Atypical alcohol that may be used is methanol or diethylene glycol monoethyl ether, and a common
base is imidazole.
The titration cell also consists of a smaller compartment with a cathode immersed in the anode solution of the main compartment.
The two compartments are separated by an ion-permeable membrane.
The Pt anode generates 12 when current is provided through the electric circuit. The net reaction as shown below is oxidation of
S02 by 12. One mole of 12 is consumed for each mole of H20. In other words, 2 moles of electrons are consumed per mole of
B-I2 + B-S02 + B + H20 - 2BH+I- + BS03
BS03 + ROH -> BH+ROS03-
The end point is detected most commonly by a bipotentiometric method. A second pair of Pt electrodes are immersed in the
anode solution. The detector circuit maintains a constant current between the two detector electrodes during titration. Prior to the
equivalence point, the solution contains I- but little 12. At the equivalence point, excess 12 appears and an abrupt voltage drop
marks the end point. The amount of current needed to generate 12 and reach the end point can then be used to calculate the
amount of water in the original sample.
The volumetric titration is based on the same principles as the coulometric titration except that the anode solution above now is
used as the titrant solution. The titrant consists of an alcohol (ROH), base (B), S02 and a known concentration of 12.
One mole of 12 is consumed for each mole of H20. The titration reaction proceeds as above, and the end point may be detected by
a bipotentiometric method as described above.
Advantage of analysis
The popularity of the Karl Fischer titration is due in large part to several practical advantages that it holds over other methods of
moisture determination, including:
High accuracy and precision
Selectivity for water
Small sample quantities required
Easy sample preparation
Short analysis duration
Nearly unlimited measuring range (1ppm to 100%)
Suitability for analyzing:
Independence of presence of other volatiles
Suitability for automation
In contrast, loss on drying will detect the loss of any volatile substance.
The major disadvantage is that the water has to be accessible and easily brought into methanol solution. Many common substances, especially foods such as chocolate, release water slowly and with difficulty, and require additional efforts to reliably bring the total water content into contact with the Karl Fischer reagents.