The Importance Of The Sample Vial During The Experiment

The material of the sample vial

The glass sample vials are most frequently seen. When talking about the material, we must first talk about the linear expansion coefficient, which means that the temperature changes every time the temperature changes. The coefficient of thermal expansion of glass depends essentially on glass’s chemical composition and also its thermal history.

The glass expansion coefficient determines the ability to resist quenching and heat. In short, it is the ability of glass to withstand severe temperature changes. The coefficient of linear expansion is inversely proportional to the temperature change that the glass can withstand.

The importance of the sample vial during the experiment

Although the sample vial does not seem to be insignificant compared to many sophisticated analytical instruments used in the laboratory, the incorrect use of the sample vial has a significant impact on the experiment, resulting in the reduction of experimental efficiency and repeatability.
Potential problems with the incorrect use of sample vials include:

• Loss of analyte due to volatilization
• Chromatographic peaks caused by solvent and septum
• Mechanical damage to the autosampler
• Sample degradation
• Poor repeatability of injection, etc.

The Importance Of The Sample Vial During The Experiment

Difference Between Flash Column And Conventional Column

The column chromatography is a kind of separation and analysis technology, it can use the liquid as the mobile phase, and paper, sheet and packed bed as the stationary phase. During the development process of chromatography technology, in order to distinguish various methods, we name them according to different operating process, such as flash column chromatography and conventional column chromatography.

Specifically, the conventional column chromatography always uses a porous stationary phase with coarse particle, and then fill the phase in the long glass column with heavy caliber. The mobile phase flows through the chromatography column only by gravity.

The mass transfer and diffusion rate of the solute in the stationary phase are slow. Moreover, the inlet pressure of the column is low and the efficiency is poor, so the analysis time is relevantly lengthy.

On the other side, the flash column chromatography uses a macro-reticular stationary phase with fine particle, and it is filled in the short stainless-steel column with minor caliber. The mobile phase flows through the chromatography column with high column pressure by the high-pressure pump.

The mass transfer and diffusion rate of the solute in the stationary phase are much faster, so that we can achieve high column efficiency and high separation capacity in short analysis time.

Difference Between Flash Column And Conventional Column

Filter Membrane Selection for Liquid Chromatography

The liquid chromatography is a qualitative and quantitative analytical instrument with high precision and sensitivity. During the use of the liquid chromatography to detect the samples, the purity requirements for the sample and mobile phase are quite high. the filter membrane plays a key role in the removal of impurities. It is necessary to properly choose the filter membrane depending on the mobile phase solution.

Aqueous Filter Membrane

The aqueous filter membrane is very suitable for water-based solutions. It has high chemical and thermal stability, which could highly resist to the strong acid and alkaline solutions. Meanwhile, it possesses high mechanical strength and a fast flow rate. It also has low adsorption capacity to proteins. Nevertheless, it is not resistant to organic solvents.

Organic Filter Membrane

The organic filter membrane is a hydrophobic membrane, which is used for organic solvents and air filtration. It is resistant to acids, alkaline, and antioxidants because of its stable chemical properties. Therefore, it is not only perfect for aqueous solutions containing acid and alkaline, but also for organic solvents such as alcohols, hydrocarbons, lipids, phenols, ketones, etc.

Nylon Filter Membrane

The Nylon filter membrane has good hydrophilicity and quite high resistance to acid and alkaline solvents. Like the organic filter membrane, it is usable for both aqueous solutions containing acid and alkali and organic solvents.

Filter Membrane Selection for Liquid Chromatography

About The Choice Of The Pipette

What is pipette

Pipette is an instrument for quantitatively transferring liquid which is generally used to remove small or micro- amounts of liquid in the analytical test.

Pipettes can be classified into air-displacement pipettes and positive-displacement pipettes according to principles. Air-displacement pipette is mainly used for standard pipetting. Positive-displacement pipette is mainly used to treat special liquids such as volatile, corrosive and viscous.

How to choose the pipette

1.Performance– the accuracy and repeatability of the pipette.
2.reliability and durability- mainly depending on the materials used in the pipette.
3.Ergonomic design-considering the following aspects.

First, the shorter moving distance of the thumb to complete a pipetting cycle means higher comfort;

Secondly, comparing thumb force to drain the same range of pipettes(the key factor affecting comfort). The less force means the lower risk of finger damage caused by long-term use;

Third, the force requires to mount or dismount the tip, the more labor-saving the better;

Fourth, the weight of the pipette is moderate, too heavy will increase hand burden, but too light may mean the material is slightly worse;

Fifth, other ancillary designs, such as the matte design of the housing and the finger hook design to further enhance comfort.

About The Choice Of The Pipette

About The Innovative QuEChERS Method

Why QuEChERS was born

How to perform trace analysis and sample preparation on increasingly complex sample matrices has become a major challenge in the industry. Nowadays, in order to meet the growing needs of the world’s population, food production has been greatly improved, which has led to the use of a variety of toxic pesticides. Even if the agricultural products themselves are not needed, they will be cast.

Therefore, for the trace inspection of these pesticides, the inspection workers must continuously improve their inspection techniques. Therefore, the pesticide residue analysis method for many types of pesticides has been paid attention to, especially during the period when our food supply frequently has pollution incidents.

What is QuEChERS

QuEChERS is a rapid sample pretreatment technology for agricultural product testing and is getting more and more attention. QuEChERS stands for Quick, Easy, Cheap, Effective, Rugged, Safe which are also the features of it.

It is the acronym for a highly beneficial analytical approach that vastly simplifies the analysis of multiple pesticide residues in fruit, vegetables, cereals and processed products thereof.

About The Innovative QuEChERS Method

Brief Intro Of Hawach Filter Cartridges

To obtain precise results, laboratory filtration is one of the most important techniques in the lab. Hawach has a lot of premium filtration supplies for your laboratory filtration applications. From filter cartridge to filter bag, filter capsule and filter housing, Hawach laboratory filtration products are designed just for you.

Hawach offers big and small filter cartridges for lab-scale and product development applications. All cartridge filters can be specified with a wide range of media options and offer superior performance for clarification, purification, and pre-filtration through sterilizing-grade filtration.

Hawach filter cartridges provide high flow rates, low protein binding, and broad chemical compatibility. For your special applications, we offer pleated filter cartridge, membrane pleated filter cartridges, metal filter cartridge, micro fiber pleated filter cartridge, and others.

Hawach filter cartridges go through cleaning processes and filter integrity tests. The cartridges will be finally drying 24 hours before packing out. They can be widely used in foods, pharmaceuticals, chemicals, and electronics.
Brief Intro Of Hawach Filter Cartridges

Features And Application Of Diaphragm Vacuum Pump

Hawach scientific diaphragm vacuum pump advanced design, high efficiency, long service life. Widely used in medical and pharmaceutical product analysis, fine chemical industry, biochemical pharmacy, food inspection, and other fields, can be used with filter device or multi-filter, simple operation, safe and reliable, meet the needs of the laboratory.

Diaphragm vacuum pump product features :

Code: SLVPGM200 Diaphragm vacuum pump
– Speed of Evacuation:120 L/Min
– Ultimate pressure: ≧0.08Mpa
– Vacuum:200mbar

Pump Head: 2
– Motor Power (W): 300W

1. This product does not need any medium (no oil), does not produce pollution, and guarantees the air to be clean.
2. New technologies and processes are adopted in the production process. Make it work smoothly, thus ensuring the ideal pressure and vacuum degree.
3. The mechanical operation system adopts international famous brand imported bearing, making the whole machine run smoothly with a small vibration.
4. The power system is designed for high-grade motor, and the fan cooling and exhaust configuration with high rotation speed enables the machine to work continuously for 24 hours. Meanwhile, the motor is equipped with an overheating and overload protection system to ensure the safe and high-energy working efficiency.
5. Air design and advanced structural innovation have obtained two national patents.

Features And Application Of Diaphragm Vacuum Pump