The Importance Of Sample Vial In The Process Of Experiment
The sample vial is a bottle with very high cleanliness. The most inert glass is used as the raw material. The spacer is PTFE/ silica gel material.
In the process of using liquid sample vials, the cleaning of liquid sample vials is a very important link, while the cleaning of liquid sample vials can be selected according to the glass instrument washing method according to the degree of contamination, there is no fixed model.
1. Soak with methanol (chromatography-pure) first, and wash with ultrasonic for 20 minutes, then drain the methanol. Then fill the chromatographic sample vial with water, ultrasonic cleaning for 20 minutes, after the water is poured dry. After drying the chromatographic sample vial.
2. Rinse with running water several times. Place in a beaker with pure water and ultrasound for 15 minutes. Change the water and ultrasound for 15 minutes. Soak in a beaker with ethanol or no water. Remove and air dry.
3. Generally is the first rinse with water after drying with sulfuric acid dichromate potassium lotion immersion. The washing method of chromatographic sample vial is the same as that of the liquid phase, etc., the first use of medical alcohol soak for more than 4 hours, and then half an hour of ultrasound, and then pour out medical alcohol, use water ultrasound for half an hour, after washing with water drying can be.
4. Pour dry chromatographic sample in the bottle. Soak all 95% alcohol, wash with ultrasound 2 times and pour dry, as the alcohol is easy to enter 1.5mL vial and can be insoluble with most organic solvents to achieve. Pour in clean water and wash with ultrasonic for 2 times. Pour dry bottle lotion, bake 1~2 hours at 110 ℃, never bake at high temperature. Cool and preserve.
5. If the fee is sufficient, it is best to use a new one every time. If you want to reuse, the cleaning method is also very important, first with strong oxidation cleaning liquid (potassium dichromic acid) soak for 24 hours, and then with deionized water in ultrasonic conditions to clean three times, the last one with methanol cleaning, drying can be used. The bottle cushion must be replaced with a new one, especially when analyzing pesticide residues. Otherwise, the quantitative results will be affected.
The importance of sample vial in the process of the experiment:
Although compared with many sophisticated analytical instruments used in the laboratory, the automatic sample feeding bottle seems insignificant, but the wrong use of sample feeding bottle or cover or pad will bring a significant impact on the experiment, resulting in the reduction of experiment efficiency and repeatability.
Potential problems that may result from the incorrect use of sample vials/LIDS/spacers include:
Loss of analytes due to volatilization.Chromatographic impurity produced by the action of solvent and spacer.Mechanical damage to the automatic sampler.Sample degradation.Poor injection repeatability.
The material of sample vial:
Most of the sample vials are made of glass. When we talk about this material, we first need to talk about the linear expansion coefficient, which refers to the change in the length of the glass for every degree change in the temperature. In short, the glass’s ability to withstand drastic temperature changes. The lower the coefficient of linear expansion, the greater the temperature variation the glass can withstand.
The classification of laboratory glass is based on its water-resistance by USP (United States pharmacopeia).
USP Type 1, grade A, 33 borosilicate glass is the most chemically inert glass and is widely used in laboratories, especially for chromatographic analysis. Class I glass consists mainly of silicon and oxygen and contains trace amounts of boron and sodium. Its dissolution is the lowest and the linear expansion coefficient is 33.
USP Type 1, Class B, 51 borosilicate glass is mainly composed of silicon and oxygen, containing trace amounts of boron, sodium, and more alkali metals than grade A glass, but still suitable for laboratory use. All brown glass is class B glass with a linear coefficient of expansion of 51.
Silanized or deactivated glass is borosilicate glass that has been deactivated by organosilanization of the glass surface. The glass surface has strong hydrophobicity and inertia, which is suitable for ph-sensitive compounds, trace analysis, and long-term sample storage.
USP Types II, III, and NP sodium-calcium glass have less chemical tolerance than borosilicate glass.
PP (Polypropylene PP) is a kind of hard material, can be processed into a variety of colors and good chemical resistance, suitable for short-term storage of much of the laboratory chemicals. The tolerance of aromatic or halogenated hydrocarbons decreases with time.PP sample vials are often used for ion chromatography because of their low iron content and can be cleaned with dilute acid and deionized water.PP sample vials also reduce exposure to hazardous materials because they can be incinerated directly after sealing.
Polymethylpentene (Polymethylpentene, TPX) is a high melting point, in the range between 0 ° -170 °C, hard, transparent material. The TPX sample vial can replace the opaque PP due to its high transparency. Chemical resistance similar to PP, TPX vials typically used for the case where the sample visually or used at high temperatures. TPX vials are relatively fragile at room temperature.