How To Choose Sample Vial In Laboratory
Types of sample vials
The sample vial is generally divided into three types: crimp top sample vials, screw thread top sample vials, snap top sample vials.
How to choose three kinds of sample vials?
The tightness of the jaw bottle is of course better than that of the screw-top bottle. After puncturing, the rubber or silica gel has a good resealability, so it is still ideal for storing reagents.
However, if some organic solvents will corrode the silica gel or rubber bottle pad during use, then the bottle pad with PTFE coating is required. If in use, the reagent is not used up at one time but will remain in the sample vial and wait for the next time. If it is used again, the sample will evaporate, because the PTFE-coated bottle pad will lose its tightness after the puncture.
It is recommended that some reagents that are not corrosive to rubber or silicone bottle pads can be stored in jaw bottles, while for corrosive reagents, it is not recommended to use jaw bottles to seal. Compared with rubber and silicone, rubber has the better sealing performance.
Snap Top sample vials and caps are a simple and effective way to ensure sealing without the need for jaw sealing. As easy as pressing in and pulling out. Crimp caps can also be used with wide-mouth snap top sample vials. The vial with a snap top cannot be pressurized.
Selection of sample vials of different materials
* Glass-general type and acid-resistant type;
* Brown bottle-for light-sensitive samples;
* Silanization/deactivation-for samples and traces that are easily adhered to the wall of the glass bottle;
* Polypropylene-used for alcohol samples or water-soluble solvents;
* Micro-lined tube-used for very small injection volume;
* High yield-for limited sample volume;
The material of the sample vial: most of the sample vials are made of glass. When you talk about this material, you have to learn a linear coefficient of expansion, which means the length of the glass changes every time the temperature changes. In short, it is the glass’s ability to withstand drastic temperature changes. The lower the linear expansion coefficient, the greater the temperature changes that the glass can withstand.
Polypropylene (PP) is a hard material that can be processed into multiple colors and has good chemical tolerance and is suitable for short-term storage of most laboratory chemicals. when aromatic or halogenated hydrocarbons are used, their tolerance decreases with time. Because of the low ion content and can be cleaned with dilute acid and deionized water, PP sample vial is often used in ion chromatography. Because sealed can be directly incinerated, so PP sample vial also reduces the exposure of harmful substances.
Polymethylpentene (TPX) is a hard, transparent material with a high melting point and a range of 0°-170°C. Because of its high transparency, the TPX sample vial can replace opaque PP. Its chemical tolerance is similar to that of PP, TPX sample vial is usually used where visual samples or high-temperature use is required. TPX sample vial is brittle at room temperature.