Glass Molecular Distillation A1-Type

The principle of wiped film evaporator is different from that of conventional distillation, which breaks through the principle that conventional steam distillation unit relies on the difference of boiling point to separate substances, but relies on the difference of the average free 

path of the movement of molecules of different substances to separate substances.

Steam distillation unit price 

is competitive in the international market. Therefore,

spd distillation

the equipment has low distillation pressure, short heating time, low operating temperature and high separation degree. At present, spd distillation technology in the industrial application of more than 100 varieties.

Structure of A1-type wiped film evaporator
1.Feeding system
– double layer constant pressure drop tank and matching heater for molecular distillation equipment.

– larger capacity feed tank matched with spd distillation
– equipped with gear pump feeding for molecular distillation equipment.
– feeding with a peristaltic pump, wiped film evaporator price will be different.

2. Main evaporation system
– spd distillation full jacket type main evaporator
– one set of hermetic heaters (RT-200/300 °C) which provide steam distillation unit a heat source
– one set of high-temperature heating and cooling circulator(-20 to 200°C)
– continuous collection of heavy or light-receiving bottles make molecular distillation equipment collection in production more convenient
– rotate the three-component collection bottle, can accept different products
– jacketed receiving bottle (integral or separate) and supporting heater
– wiped film evaporator gear pump outlet with heater
3. Vacuum system
– molecular distillation equipment coil cold trap and supporting cryogenic machine
– continuous collection of bottles, receive the liquid condensed from the cold trap– gear pump discharge effectively improves work efficiency and saves time.
– wiped film evaporator vacuum pump with higher extraction speed
– diffusion pump for molecular distillation equipment, provide a vacuum of 0.1 Pa.
4. Control system
– spd distillation condensing system
– one exhaust valve, adjust the vacuum inside the wiped film evaporator system

– one coil condenser, the molecular distillation equipment effective condensation area is large, which can liquefy the gas quickly
– one collect bottle
– one refrigerator

Glass Molecular Distillation A1-Type

Advantages And Disadvantages Of Vacuum Filter

The vacuum filter device is an instrument used for vacuum filtration in the laboratory. Generally speaking, filtration can serve the purposes of trapping particulate matter, clarifying filtrate, degerming, solid-liquid separation, degassing, and defoaming. And vacuum suction filter is in the middle of the suction filter bottle is to use membrane filter, filter membrane suction filter bottle can be divided into fluctuation two parts, the upper costumes for filtering liquid, lower costumes filtered filtrate.

Due to the membrane filter can produce great resistance to liquid by, cause filter cannot effectively by someone who comported himself slowly or liquid, so the so-called vacuum suction filter is to connect the suction filter bottle of vacuum pump, reduce the membrane filter below the bottles of vacuum degree, make the air outside push samples by membrane filter in the filter bowl. Therefore, vacuum filtration is a relatively complete system with multiple components. The absence of any part will affect the normal use of the instrument.

1.Vacuum filter pump: no oil pump is a dry vacuum pump that can be directly used after connecting the power supply. The suction end of the filter pump is equipped with a vacuum regulating valve. The vacuum regulating valve is equipped with a vacuum gauge to facilitate the observation of the working state of the instrument and adjust the pressure and pumping speed according to the needs.

In the purchase of the suction filter consultative is must buy the suction filter pump, due to the membrane filter, filter paper, filter cloth or a mesh aperture of the very small, can produce a large resistance to liquid by, caused by the liquid can’t effectively through the membrane, the suction filter pump suction filter bottle be inside and outside differential pressure formation, so that the outside air rapidly promote the filtrate by filter membrane, do not use the suction filter pump liquid can only be natural osmosis membranes, a trickle of drip into the collection of liquid bottle. So the filter pump is essential.

2. Filter cup: hold the filtered liquid. Generally, it is more convenient to choose a graduated cup.

3. Automatic liquid suction cup cover: users only need to use a hose to connect one end to the automatic liquid intake interface and put the other end into the filtrate to be filtered. After opening the switch, the filtrate will be automatically sucked into the filter cup and filtered.

4. Filter membrane placement base: it is used to prevent the filter membrane. Generally, the surface should be flat, and the filter membrane should not be cut.

5. Extraction bottle: used for holding filtrate or waste liquid after filtration. There is a quick drainage port at the bottom of the filter bottle. After filtration, it is not necessary to remove the filter bottle and pour out the filtrate. Just loosen the clamp at the bottom of the filter bottle to drain the filtrate quickly, or even change the drainage edge. Improve efficiency and easy operation.

Fixed seat: the suction filter bottle shall be stabilized to avoid the accidental operation or shaking of the suction filter bottle.

Filter membrane: filter membrane with appropriate aperture and material can be selected according to your own needs. The aperture and material are not affected by the filter device and can be selected according to the customer’s experimental requirements.

6.Water-resistance protector: the built-in PTFE hydrophobic film can block 100% of the suction liquid.

Vacuum filter is a device that realizes solid-liquid separation with vacuum negative pressure as the driving force. In terms of structure, the filtration section is arranged along the horizontal length, which can continuously complete filtering, washing, sucking and drying, press cloth regeneration, and other operations.

Vacuum rubber belt filter can be widely used in metallurgy, mining, chemical industry, paper making, food, pharmaceutical, environmental protection and other fields of solid-liquid separation, especially in the desulfurization of flue gas gypsum dehydration (FGD) filter press equipment have good applications.

Advantages of vacuum filter:
1. Continuous operation;
2. Remove dirt from the filter cake by forced dissolution and recovery or backwashing, especially for vacuum belt filter;
3. Vacuum belt filter – relatively clean filtrate can be obtained by using the clarifier;
4. Easy access to the equipment for filter cake sampling or other operations;
5. Easy to control operating parameters, such as filter cake thickness or washing speed;
6. Various construction materials can be used;
7. Continuous disk filtration.

Disadvantages of vacuum filter:
1. High residual moisture in filter cake;
2. The structure is not airtight.

Advantages And Disadvantages Of Vacuum Filter

Describe The Importance Of Sample Vial And Septa Quality

The importance of sample vial
If the tolerances are not strictly controlled, the market size and wall weight of the autosampler vial may be different, which will affect the sample volume in the vial. It is very important for a small number of samples. HAWACH’s strict tolerance control runs through the entire manufacturing process, from the initial design to the final photoelectric scanning inspection process to ensure the accuracy of each sample bottle and cap specifications. The integrity, cleanliness, and uniformity of the sample vials are critical to today’s demanding applications. All HAWACH sample vial comply with ISO9001 clean environment requirements The unique packaging guarantees cleanliness and safety during transportation.

The material of sample vial

Type I, 33-expanded borosilicate glass
It is currently the most chemically inert glass and is usually used in analytical laboratories to obtain high-quality experimental results. Its expansion coefficient is about 33×10 ^ (-7) ℃, mainly composed of silicon oxide, and also contains trace amounts of boron and sodium. All Waters clear glass sample bottles are Type I 33-expanded glass.

Type I, 51-expansion glass
All Waters brown glazed products are 51-expanded glass. Deactivated glass (DV) For analytes with strong polarity and binding to the polar glass surface of the glass, deactivated vials may be a good choice. The glass sample vial is treated with a glass-phase reactive organosilane to produce a hydrophobic glass surface. Deactivated vials can be stored dry indefinitely.

Polypropylene plastic
Polypropylene (PP) is a non-reactive plastic that can be used where glass is not suitable. Polypropylene sample vials can still maintain a good seal when fired, thereby minimizing the possibility of exposure to potentially hazardous substances. The maximum operating temperature is 135 ℃.

The importance of septa
To prevent contamination and prevent syringe and instrument damage, the correct septa selection is crucial. The following are some issues that you should pay attention to:

1. Temperature control
At higher temperatures, the septum will degrade and cause sample contamination. The rubber septum is only stable below 90℃, so it is not suitable for high-temperature applications. Generally, PTFE-lined silicone rubber septa are the best choice for various temperatures.

2. Debris
When the syringe diameter is too large relative to the septa or the septa material cannot withstand multiple injections, debris will be generated. At this time, the septa material will fall off into the sample vial and contaminate the sample. Here is how to prevent debris:
a. Choose PTFE-lined septa to prevent the septum material from entering the sample;
b. Make sure the syringe is not damaged, consider using a side hole syringe instead of a tapered syringe;
c. The use of pre-perforated septa can almost completely eliminate debris.
d. For highly sensitive samples, we recommend the use of PTFE lined (“sandwich”) septa, because the PTFE layer can act as a chemical-resistant barrier.

3. Resealability
Resealability is an important factor to consider when choosing septa. PTFE / red rubber septa are not recommended for multiple injections or need to store samples for later analysis. When a long time is required between injections or any type of standard is added, PTFE / silicone rubber / PTFE is always the best choice.

The disadvantage of using poor quality vials and seals on the autosampler
Common problem
The thickness of the bottom of the sample vial is inconsistent
Autosampler sequence stopped
Seal leak not detected
Septa that are not properly displaced or positioned
Ghost peak

Influences
The inconsistent sample was taken; damaged injection syringe
Miss-taking or missing sample vials; loss of precious samples
Sample loss, volatilization; may contaminate the sample
Sample loss; sample contamination
Contamination of vial cap septa

Describe The Importance Of Sample Vial And Septa Quality

About The Highlights Of HAWACH QuEChERS Products

Brief introduction of QuEChERS
As we all know, agricultural residues can affect people’s health. Regulations around the world are also becoming stricter with regard to the detection of pesticide residues in food. The original method of pre-treatment of pesticide residues is time-consuming and laborious. Therefore, QuEChERS was proposed and developed in 2003.

After adding salt to the solid sample in the aqueous solution, it is subjected to acetonitrile extraction, followed by liquid-solid extraction (that is, dispersion matrix extraction) to remove most of the interferences present in the acetonitrile, and the extract can be directly analyzed by mass spectrometry. Now QuEChERS has become the global standard sample processing method for detecting pesticide residues in fruits and vegetables. In addition, its application also involves more and more different fields, such as the detection of antibiotics, drugs, drugs of abuse, and other contaminants in meat, blood samples, wine, and even soil.

HAWACH QuEChERS products include extraction kits and purification kits; extraction kits include salt packs and 50ml centrifuge tubes to cater for different customer needs.

The purification kit is the adsorbent directly installed in the centrifuge tube, including 2ml and 15ml. Another type of product is a set, that is, extraction kit + purification kit, by which customers can get the whole set of experiments.

Highlights
1. HAWACH QuEChERS products have been tested with EN and AOAC methods in different types of fruits, vegetables and reports or called product recovery rate test data. You can contact HAWACH to get it, if necessary.
2. The products are mainly composed of salt, adsorbent, bags containing salt packs, centrifuge tubes, and the corresponding quality control and testing are carried out for the four types of product companies.
Salt: all products are above the laboratory analysis pure grade, and the magnesium sulfate used for water removal is packaged after drying in a high-temperature oven to prevent the product from losing its original effect due to moisture;
Salt bag: If the salt bag is not tight, magnesium sulfate is easy to absorb moisture and make the salt bag heavier. Therefore, HAWACH placed the salt bag for 1 week, 2 weeks, and 1 month. The weight test at different time periods shows that the quality is constant and the seal is good.
Adsorbent : good adsorption of impurities, high recovery rate, high cost-to-price ratio.
Centrifuge tube: less impurities elute in organic solvents and do not interfere with the detection of pesticide residues; good sealing, no leakage of organic solvents; corrosion resistance, high speed centrifugal resistance.

About The Highlights Of HAWACH QuEChERS Products

Hawach To Introduce The Flash Column Comprehensively

Born
In 1978, Sill invented Flash chromatography, and the article was published in J.O.C. Since then, the Flash chromatography method has been established, and new equipment has been constantly emerging. The narrow sense of the Flash column refers to a low-pressure short column preparation liquid chromatography system that uses compressed air to generate pressure and accelerate the elution speed of the mobile phase. The generalized Flash column system refers to all low-pressure liquid chromatography systems for infusion methods.

Flash column is born out of open glass column chromatography and is mainly used for separation and purification of natural products and organic synthesis products. The classical Flash column consists of a glass column, a storage bottle, and a compressed air regulating valve. This type has low cost and is easy to observe, but has low pressure and easy to break.

Many laboratories now place a pressurized ball on the top of a glass column, which is a similar product. After improvement, a classic Flash column system was formed, which is composed of an infusion pressure tank, flow regulating valve, Flash pre-packed column, and sample loading device. The classical Flash column still uses air pressure with a 0-7bar pressure range. The column length is about 15cm, and the particle size of the packing is 40-60. Samples can be loaded on solids and liquids, and fractions can be collected manually.

Development
After more than 20 years of development, the Flash column has been widely used by people as conventional purification and separation equipment, such as Glaxo, Pfizer researchers have hundreds of Flash chromatography devices, and many instrument manufacturers in the world provide a full set of Flash chromatography device.

In recent years, due to the intensification of scientific research competition and the increase in labor costs of laboratories, a higher degree of automation and separation speed have been required, resulting in automated Flash column, with devices equipped with columns, chromatography pumps, detectors, automatic fraction collectors, and workstation. Some instruments also have a gradient elution system, a column switching system, and an automatic sampling system.

The optimized conditions can be selected to achieve unmanned operation, which greatly reduces labor costs and speeds up development. At present, some people in China use peristaltic pumps for infusion and separation with plexiglass columns. Strictly speaking, they cannot be separated from small molecules of the organic phase, but only for biochemical separation, otherwise, the instrument will be damaged.

Advantages
The Flash column has many advantages compared with others.
1. Fast speed
2. A large amount of preparation: at least double the amount of sample than the same diameter HPLC preparation column.
3. Low cost and the use of solvent saves more than the glass column, the silica gel column can be used multiple times, saving the amount of silica gel.
4. Easy to use: no special solvent treatment is required, the sample can be applied by the dry method, and the person does not need special training.
5. Compact size
6. High reproducibility.

The effect of chromatography mainly depends on the optimization of the elution solvent and the packing effect of the column. When dealing with the relationship between preparation and HPLC, the following principles should be followed:
(1) When only Flash column can be used, there is no need to prepare HPLC
(2) First use Flash column, purification and then preparative HPLC

Other usage techniques include:
① First select anti-solvent and load by TLC
② Using short thick column (diameter: length ≤ 1: 7)
Also, its features include various available phases: C8, C18, Silica, NH2, CN, Alumina Acidic, Alumina Neutral, Alumina and it can withstand the pressure of 100ps.

Hawach To Introduce The Flash Column Comprehensively

Matters Needing Attention During The Use Of Glass Fiber Extraction Thimbles

Introduction of glass fiber extraction thimbles
The ultra-fine glass fiber extraction thimbles are made of 100% alkali-free glass fiber and processed at high temperature, free of adhesives and chemically inert. It can collect fine and submicron particles. It is a filtering device for capturing pollution source particles, acid mist, aerosol, beryllium compounds, and so on, with high-efficiency and high-quality. It has the advantages of high-temperature resistance, small weight loss, high collection efficiency, high strength, etc., and can be widely used in the collection of samples of pollution source particles and metal compounds in various situations.

In the monitoring of air pollution, the monitoring of smoke emission concentration is a relatively conventional monitoring project and a relatively mature monitoring project. Whether it is monitoring the location of sampling points or monitoring equipment, there are clear quality control and management standards. In daily monitoring, the sampling extraction thimble is mainly glass fiber.

The glass fiber extraction thimbles are used to sample atmospheric particles, and the relatively stable weight of the extraction thimble becomes the key to the success of the experiment. For this, there are two key factors:
If there is glue, the volatilization of the glue component during heating will cause weight loss, so it must be 100% glue-free;
The extraction thimble must be brittle if there is no glue, and debris is likely to fall off during the experiment, so it must have a higher strength of adsorption.

The above two contradictions have also become key considerations in the manufacturing process. The glass fiber extraction thimble produced by HAWACH has solved the above problems.

Item code /Parameters	SLGET32120			SLGET2590		SLGET2870
Maximum temperature	600℃
background response(%)	SiO2	Fe2O3	Al2O3	CaO	MgO	K2O	Na2O
	57.22	0.3	14.63	16.12	3.66	0.16	0.38
Flow pressure (mmHg)	14-16			16-18		18-20

Use Instructions
1. The extraction thimbles should be protected from squeezing and moisture during transportation and storage;
2. Before using the extraction thimbles, use a soft bristle brush and ear washing ball to dust off the outside and fiber debris;
3. The dried extraction thimbles is placed in a 105℃desiccator, cooled for 30 minutes, then weighed on a 1/10000 balance, and write down the weight;
4. Before use, check the two slightly clogged and hoop of the sampling head, whether the taper is the same and matching, and whether the gap is appropriate. When the extraction thimble is loaded and unloaded, it is not affected by tearing, shearing and other forces, so that theextraction thimble mouth is not broken;
5. If the extraction thimble is found to have gaps, cracks or uneven thickness, it can not be used, so as to avoid sampling failure caused by airflow;
6. It is to be used within the specified temperature range, to ensure that the extraction thimble works under sufficient strength. When the glass fiber is heated above 200℃and then cooled, its strength begins to decrease continuously. After the fiber is heated to 510℃and cooled, the strength remains only 35% of the original. The fiber can maintain high strength when heated, but after cooling, its strength is greatly reduced;
7. After sampling, gently remove the extraction thimble from the sampler, place it in a 100℃ oven for 30 minutes, and then place it in a desiccator for 30 minutes to weigh and record the weight;
8. For the collection of finer particles such as asphalt smoke, you can choose to add a heavy rubber-free extraction thimble.

Matters Needing Attention During The Use Of Glass Fiber Extraction Thimbles

Classification And Maintenance Of HPLC Column

1、 Basic knowledge of HPLC column
HPLC column is a kind of separation and analysis method, separation is the core, so the chromatographic column responsible for separation is the heart of the chromatographic system.

The requirements for the HPLC column are high column efficiency, good selectivity, and fast analysis speed. The particle size of various kinds of silica gel used in HPLC column, as well as the bonding phase, alumina, organic polymer microsphere (including ion exchange resin), porous carbon, etc., which are sold on the market, are generally 3, 5, 7, 10um, and the theoretical value of column efficiency can reach 50000-160000 / m.

For general analysis, only 5000 plates are needed for column efficiency; for homologous analysis, only 500 plates are needed; for more difficult separation materials, up to 20000 columns can be used, so the column length of about 10-30cm can meet the needs of complex mixture analysis.

Column efficiency is affected by internal and external factors. In order to achieve the best efficiency of the column, in addition to the small dead volume outside the column, a reasonable column structure (to reduce the dead volume outside the packed bed as much as possible) and filling technology are also required. Even if the best filling technology is used, the filling condition in the center of the column and along the pipe wall is always different.

The position close to the pipe wall is relatively loose, which is easy to produce ditch flow, fast flow rate, affect the flow pattern of the flushing agent, and widen the spectral band, which is the pipe wall effect. The thickness of the tube wall area is about 30 times the material diameter from the tube wall inward. In general liquid chromatography system, the effect of external effect on column effect is much greater than that of the tube wall effect.

1.HPLC column structure
The chromatographic column is composed of a column tube, pressure cap, ferrule (sealing ring), sieve plate (filter), joint, screw, etc. The column pipe is mostly made of stainless steel. When the pressure is not higher than 70kg / cm2, thick wall glass or quartz pipe can also be used. The inner wall of the pipe requires a high degree of finish. In order to improve the column efficiency and reduce the pipe wall effect, the inner wall of the stainless steel column is mostly polished. Some people also apply fluoroplastics on the inner wall of the stainless steel column to improve the smoothness of the inner wall.

2. The effect is the same as that of polishing. The column joints at both ends of the chromatographic column are equipped with sieve plates, which are sintered stainless steel or titanium alloy with a pore diameter of 0.2-20um (5-10um), depending on the particle size of the packing. The purpose is to prevent the packing from leaking out. The inner diameter of the column is generally determined according to the length of the column, the particle size of the packing, and the reduced flow rate, so as to avoid the pipe wall effect.

3. The development direction of HPLC column
Due to the emphasis on the analysis speed, the short column has been developed. The length of the column is 3-10cm, and the particle size of the filler is 2-3um. In order to improve the analytical sensitivity and connect with MS, a narrow-diameter column, capillary column, and micro diameter column with an inner diameter of less than 0.2mm were developed.

The advantages of small-diameter columns are ① saving mobile phase; ② increasing sensitivity; ③ less sample; ④ using the long column to achieve high resolution; ⑤ easy to control column temperature; ⑥ easy to realize LC-MS joint use.

However, as the volume of the column becomes smaller and smaller, the effect of out of column effect is more significant. It needs a smaller cell volume detector (even on-column detection), smaller dead volume column joints, and connecting parts. The matching equipment shall have the following performance: the infusion pump can accurately output a low flow rate of 1-100ul / min, and the injection valve can accurately and repeatedly inject small volume samples.

Because of the small amount of sample and the requirement of high sensitivity detector, electrochemical detection assist mass spectrometer has outstanding advantages in this respect. The performance of the HPLC column is not only related to the performance of the stationary phase but also related to the filling technology. Under normal conditions, when the particle size of the filler is more than 20um, the dry method is more suitable for the preparation of the column; when the particle size is less than 20um, the wet method is more ideal.

Generally, there are four filling methods: ① high-pressure homogenization method, which is mostly used for the filling of analytical columns and small-scale preparation columns; ② radial compression method, waters patent; ③ axial compression method, which is mainly used for filling large-diameter columns; ④ dry method, which is highly technical, most laboratories use filled commercial columns.

It must be pointed out that the filling technology is an important link in obtaining HPLC columns, but the fundamental problem lies in the performance of the packing itself and the reasonable structure of the matching chromatograph system.

Classification And Maintenance Of HPLC Column