The importance of the sample bottle in the experiment process and its material
The importance of the sample bottle in the experiment process:
Although compared with the many sophisticated analytical instruments used in the laboratory, the automatic sample injection bottle may seem insignificant, but the incorrect use of the sample bottle or cap or pad will have a significant impact on the experiment, resulting in experimental efficiency and repeatability. The reduction.
Potential problems that can be caused by incorrect use of vials/caps/ septa include:
• Loss of analyte due to volatilization
• Chromatographic peaks caused by the interaction of solvent and septum
• Mechanical damage to the autosampler
• Sample degradation
• Poor injection repeatability, etc.
Material of sample bottle:
Most of the sample bottles are made of glass. When talking about this material, we must first talk about the linear expansion coefficient, which refers to the change in the length of the glass for every degree of temperature change. In short, it is the ability of glass to withstand drastic temperature changes. The lower the linear expansion coefficient, the greater the temperature change the glass can withstand.
The classification of laboratory glass is established by the USP (United States Pharmacopeia) based on its water resistance.
USP Type 1, Class A, 33 borosilicate glass is the most chemically inert glass and is widely used in laboratories, especially for chromatographic analysis applications. Class I glass is mainly composed of silicon and oxygen, and contains trace amounts of boron and sodium. It has the lowest dissolution and a linear expansion coefficient of 33.
USP Type 1, Grade B, 51 Borosilicate glass is mainly composed of silicon and oxygen, and contains trace amounts of boron, sodium and more alkali metals than Grade A glass, but it can still meet laboratory use. All brown glass is grade B glass with a linear expansion coefficient of 51.
Silanized or deactivated glass is a borosilicate glass that has undergone a deactivation treatment of organosilanization on the glass surface. The glass surface has strong hydrophobicity and inertness. It is suitable for pH-sensitive compounds, trace analysis and Long-term sample storage.
USP Types II, III and NP soda lime glass are not as chemically resistant as borosilicate glass.
Post time: Oct-22-2021
