Laboratory analytical instruments | Laboratory equipment

Nanjing Acon Scientific Instruments is based in the scenic city of Nanjing, leveraging its convenient and well-connected transportation network to provide analytical testing users across various provinces and cities in China—including universities, R&D enterprises, pharmaceutical companies, and others in fields such as medicine, chemical engineering, food, environment, life sciences, and third-party testing—with high-precision analytical instruments and related services. These include high-quality new/refurbished liquid chromatographs, gas chromatographs, LC-MS, GC-MS, as well as consumables, accessories, maintenance, repair, certification, leasing, and relocation services for internationally renowned brands such as Agilent, Waters, Thermo, Shimadzu, and AB Sciex.
We also supply imported/domestic laboratory instruments and equipment, such as ion chromatographs, atomic absorption spectrometers, UV spectrophotometers, infrared spectrometers, moisture titrators, polarimeters, electronic balances, stability test chambers, and other related products.

Moisture Titrator:
Depending on the properties of the sample for moisture determination, there are increasingly diverse methods for measurement. A variety of moisture analyzers meet the laboratory's needs for quantitative moisture analysis. This article briefly describes several commonly used moisture determination methods.
1. Dew Point Method: The dew point method is simple to operate, and the instruments are not complex. The results are generally satisfactory and are commonly used for measuring trace moisture in permanent gases. However, this method is subject to many interferences; some easily condensable gases, especially at high concentrations, may condense before water vapor, causing interference.
2. Drying Method: Mainly used for determining moisture in solid samples by heating to remove water. This method is commonly applied to most solid samples (bulk samples need to be crushed) and is relatively simple to operate;

However, it must meet the following conditions: 1. The sample must not contain bound water; 2. Water must be the only volatile substance; 3. Chemical changes in other components of the sample due to heating must be negligible. The drawbacks are lower accuracy and unsuitability for liquid, gas, or samples containing volatile substances.

3. Distillation Method: An organic solvent immiscible with water and the sample are heated in a distillation-type moisture determination device to separate the water from the sample. The moisture content is calculated based on the volume of distilled water. This method uses simple and inexpensive equipment but has several disadvantages: 1. Water and organic solvents are prone to emulsification; 2. Moisture in the sample may not be completely volatilized; 3. Water may adhere to the condenser walls, causing reading errors; 4. Besides water, a large amount of volatile substances may be present. Therefore, accuracy is low, errors are significant, and the measurement time is long. It is suitable for samples where high precision in moisture content is not required and testing frequency is low.

4. Karl Fischer Method: Applicable to the determination of water content in most inorganic and organic compounds. Karl Fischer moisture analyzers have been improved over the years and are divided into two types: Karl Fischer titration and Karl Fischer coulometry. Karl Fischer titration moisture analyzers are mainly used for samples with higher water content, but they are less effective for samples with low moisture levels and are relatively complex to operate.

In contrast, Karl Fischer coulometric moisture analyzers are suitable for samples of any water content, particularly excelling in measuring low-moisture samples. Due to their advantages of simple operation, accurate measurement, and stable performance, they can quickly determine moisture content in liquids, solids, and gases. This method is globally recognized as a specific and accurate chemical method for determining water content and serves as a universal standard analytical method widely used in petroleum, chemical, power, pharmaceutical, pesticide industries, as well as academic and research institutions.
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