Pipettes & Bottle-Top Dispenser

Let me really invite the protagonist of this promotion – Pipettes & bottle-top. The pipette is one of the most commonly used popular pipettes used by the experimenters, and the bottle-top dispenser is also a common instrument used in experiments. They are clearly nice and can really help out with a lot of operational difficulties in the experiment.

Basic knowledge

In general, they are a common device for removing liquids. The pipette is suitable for removing small amounts of liquid, and the bottle-top dispenser is used to take large amounts of solution.

Scope of application

The bottle-top dispenser is suitable for general acids/bases and low concentration of strong acids/alkalis/oxidants. It can perform accurate and repeatable liquid separation operation without waste of reagents, and at the same time provide safety assurance for operators and experimental environment.

In the study of analytical testing, the pipette is generally used to measure a small amount or a small amount of liquid. Different specifications or sizes of pipettes are used with the corresponding sizes of the spearhead.

Maintain

The shapes produced by different manufacturers and are slightly different, but the maintain principle for removing liquids are basically the same：removal of pollutants timely；clean or disinfect regularly; avoid placing at high temperature to prevent deformation/leakage/misalignment.

Pipettes & Bottle-Top Dispenser

The Source And Control Of Pollution In Sampling

Source of Pollution
Potential sources of pollution include the following:
1. Pollution from the previous sample which remained in the sample vial.
2. Pollution from the sampling position.
3. Pollution from water remained on the sampling rope.
4. Pollution from the sample vial itself.
5. Pollution from the vial cap and vial neck by dust and water.
6. Pollution from laboratory workers’ hands, gloves, and improper operation.
7. Pollution from waste gas emissions inside the sampling equipment.
8. Pollution from impurities in the fixing agent.

Control of Pollution
The frequently-used measures to control pollution in sampling include the following:
1. Keep the sample vials far away from pollution to ensure high-quality data analysis.
2. Avoid churning the waters in sampling position.
3. Thoroughly clean the sample vials and equipment.
4. Store the sample vials in a safe place to prevent vial caps and vial corks from being polluted.
5. Scrub and dry the sampling ropes after sampling, and store them afterward.
6. It is quite important to avoid touching samples by hands and gloves in the sampling of microorganism.
7. After sampling, check if there are big particles inside each sample. Resampling if necessary.

The Source And Control Of Pollution In Sampling

How To Choose Syringe Filters In The Lab?

Consisting of a filter medium and housing or holder that constrains and supports the syringe filter media in the sample’s path, filters are good tools when you need removing particulates from samples in the lab.

We have three basic types of laboratory filters.

Membrane filters size rating of the membrane is determined the size of the pores. Centrifugal filters are suitable for separating such as protein or nucleic acid desalting and concentration. These devices drive the liquid through the filter through centrifugal force. And syringe filters which consist of a filter element and housing assembly are used when a sample must be filtered before entering a syringe.

To select the best filter for your process, ask yourself the following questions:

1. What are you going to filter?
2. What is the size and nature of the particles or molecules to be removed?
3. Chemical composition of your sample.
4. Viscosity.
5. Suitable temperature.

More to be concerned upon your applications:
1. To achieve the separation, what pore size or nominal molecular weight rating is required?
2. Do you need a sterilizing filtration?
3. How quickly do you need to filter?
4. Pressure-driven or vacuum-driven filtration?

Now, your knowledge is improved to obtain accurate separation of your sample, mobile phase or other liquid.

How To Choose Syringe Filters In The Lab?

The Method Of Cleaning Sample Vial

The cleaning of sample vial is very important. Usually, according to the principle of glass instrument washing and the degree of pollution to choose cleaning methods, there is no fixed mode. The specific methods are as follows:

Method one:
1. Dry the sample in the sample vial.
2. Immerse in 95% alcohol, wash twice with ultrasound and then dry, because alcohol is easy to enter 1.5mL vial, and can be soluble with most organic solvents to achieve;
3. Pour in clear water and wash twice with ultrasound.
4. Pour the lotion in the drying vial and bake at 110 degrees Celsius for 1-2 hours. It can’t bake at high temperature.
5. Cooling and preserving.

Method two:
1. Rinse the tap water several times.
2. Put it in a beaker filled with pure water and ultrasonic for 15 minutes.
3. Change the water and ultrasound for 15 minutes.
4. Finally, take out the natural air-drying.

Method three:
1. Soak in methanol for 20 minutes, then dry the methanol.
2. Fill the sample bottle with water, wash it with ultrasound for 20 minutes, and then dry it.
3. Finally, the sample vial will be dried.

The Method Of Cleaning Sample Vial

The History Of Flash Column Chromatography

Flash column chromatography method is to separate the constituents from the mixture and thus purify it. In a word, flash column chromatography makes the samples go through the column which is filled with gel to achieve separation.

In the beginning, the founder of flash column chromatography, Mr. Still together with his colleagues had been using medium pressure chromatography and short column chromatography to replace long column chromatography. Later they decided to combine the above two methods to overcome the defects of time-consuming and low recovery.

Initially, the gel used for filling the column is silica gel, and it is still widely applied nowadays. Laboratory workers use air pressure to push the solvent through the silica gel column, and then use the same solvent to make the sample go through the column. At last, they collect purified constituent. The whole process costs about 5 to 10 minutes.

Since the first outcome of silica gel flash column chromatography, it has been widely applied in the field of organic chemistry. Compared with high-performance liquid chromatography, the resolution ratio of flash column chromatography has reached the medium level.

The History Of Flash Column Chromatography

PVDF Membrane Filter Media Introduction

The hydrophilic polyvinylidene fluoride membrane filter is commonly used for the purification and filtration such as tissue culture media, additives, and other sterilization filtration solvents, chemical raw materials, aseptic processing of reagents, and for filtration of high-temperature liquid, etc.

Features:
PVDF is with high mechanical strength, high tensile strength, good heat resistance, and chemical stability, low protein adsorption rate; strong negative electrostatic and hydrophobic; hydrophobic and hydrophilic. However, it cannot tolerate acetone, DMSO, THF, DMF, dichloromethane, chloroform, etc.

Applications:
The Hydrophobic and hydrophilic PVDF membrane filter and syringe filters are mainly used for gas filtration and high-temperature liquid filtration;
The hydrophilic polyvinylidene fluoride membrane Filter available from membrane filters discs and membrane filter roll.
The hydrophilic polyvinylidene fluoride syringe filter available of non-sterile and sterile filters, complete filter size and pore size in supply for customers choice.

PVDF Membrane Filter Media Introduction

Introduction of Sampling System for Cationic Chromatographic Columns

The cation chromatography column is a kind of high-performance liquid chromatography, which is a liquid chromatography method for analyzing anions and cations. The method has the advantages of good selectivity, sensitivity, rapidity, and simplicity, and can simultaneously measure various components.
The catalytic column injection system
There are three main types of ion chromatography injections: pneumatic, manual, and automatic injection.

First, the manual injection valve
The manual injection uses a six-way valve, which works in the same way as HPLC, but the injection volume is larger than HPLC, generally 50 μL. The sample is first filled with a metering tube in a low-pressure state, and when the valve is rotated clockwise to another position, a sample of a fixed volume stored in the metering tube is sent to the separation system.

Second, the pneumatic injection valve
The pneumatic valve is powered by certain helium or nitrogen gas pressure. After the two-way four-way loading of the quantitative tube, sampling and injection are carried out, which effectively reduces the error caused by the different movements of the manual injection.

Third, automatic injection
The autosampler is automatically controlled by the chromatography workstation to perform a series of manipulations such as sampling, injection, and cleaning. The operator only needs to load the samples into the storage machine in sequence. The working steps of the disc type autosampler are as follows:

(1) The motor drives the storage tray to rotate, and the sample to be analyzed is placed directly below the sampling needle.
(2) The motor rotates forward, the screw moves the slider downward, inserts the sampling needle into the sample plastic cover, the slider continues to move down, pushes the bottle cap into the bottle, and the sample flows through the pipe under the cap extrusion Sample valve quantitative tube, complete the sampling action.
(3) The injection valve is switched to complete the injection.
(4) The motor is reversed, the screw moves the slider up, and the sampling needle returns to the original position.
The automated injection can achieve a wide range of sample injections.

Introduction of Sampling System for Cationic Chromatographic Columns