The service life of a column is mainly measured by the efficiency of column efficiency and column pressure. If a column is too low in efficiency or the column pressure is too high, it is generally considered that the column has ended. Therefore, the key to extending the life of the column is to eliminate the factors that cause the column efficiency to drop and the column pressure to rise. Here are the routine maintenance methods for your column:
First, the pH of the mobile phase should be within the range of use. Due to the presence of Si-C and Si-O bonds in the filler, the mobile phase exceeds its pH range, which will lead to the loss of the silica matrix and the carbon chain breakage of the bonded phase, resulting in a decrease in column efficiency. The service life is shortened. It is often difficult to recover the column due to damage to the column due to improper pH control of the mobile phase, so care must be taken to strictly control the pH of the mobile phase.
2. Removal of solid particles in the sample and mobile phase and solid particulate matter contained in the mobile phase can block the chromatographic sieve plate. Blockage of the sieve plate not only causes an increase in column pressure, but also causes a decrease in column efficiency. Because the clogging of the sieve plate will cause uneven flow, the chromatographic peak shape will be tailed and widened, thereby reducing the efficiency of the column. Therefore, it is recommended to use ultrapure water and chromatographically pure reagents to filter the sample before the sample is analyzed, and the mobile phase is passed through a 0.45 μm filter.
Third, the use of guard column or in-line filter sample and mobile phase after filtration does not completely eliminate solid particulate matter, because the wear of the pump, the aging of the seal ring and the pipeline will also produce solid particulate matter, which is carried by the mobile phase. Into the column, block the sieve plate, resulting in increased column pressure and reduced column efficiency. Both the guard column and the in-line filter have sieve plates with the same pore size as the column pores, thus preventing solid particles from reaching the column and preventing blockage of the column. Since the increase in column pressure is a large percentage of analytical failures, it is recommended that you add a guard column or inline filter to the column injection end, in addition to filtering the sample and mobile phase.
If you confirm that the column pressure rise is due to plugging of the injection end screen, you can choose to remedy the following:
1. Add a guard column or an in-line filter in front of the column, and then reverse-collapse the column with methanol and water = 20/80 ml/min for 180 min.
2. Add a guard column or inline filter to the column injection end and use it in reverse.
Fourth, the correct use of buffer salt buffer salt is usually soluble in water, difficult to dissolve in organic solvents, so improper use of buffer salts will cause it to precipitate, block the pores between the filler matrix and the gap between the particles, so that the filler is knotted, the column pressure rises At the same time, it hinders the free stretching of the carbon chain bonded on the substrate, which reduces the retention capacity of the column and reduces the column efficiency. After the buffer salt is precipitated, removal is very difficult, so proper use of buffer salts is very important to extend the life of the column.
The correct use of buffer salts is to prevent the precipitation of buffer salts, so the correct use of buffer salts can be attributed to one sentence: to filter before use, rinse after use. The specific method is as follows:
1. Isocratic conditions: Before and after using the buffer salt, the transition mobile phase should be washed at a flow rate of 1.0 ml/min for 60 min; another method of removing the buffer salt after use is to flush the column with a transient mobile phase at a flow rate of 0.2 ml/min. overnight.
2. Gradient conditions: Before running the gradient with the mobile phase containing the buffer salt, rinse with the same mobile phase with the initial mobile phase at a flow rate of 1.0 ml/min for 60 min, and then rinse the column with 1.0 ml/min with the transition mobile phase. 120min. The gradient setting of the buffered salt mobile phase should be as gentle as possible to avoid buffer salt precipitation during the gradient process.
Note: The transition mobile phase means that the composition of the organic phase and the aqueous phase is the same as that of the analytical mobile phase, except that the transition mobile phase does not contain buffer salts.
3. Remedy for buffer salt precipitation:
1) Scheme 1: Backwash the column for 120 min with methanol/20/80 at a flow rate of 1.0 ml/min at 35 °C.
2) Scheme 2: The column was backflushed back and forth at a flow rate of 0.2 ml/min with methanol/water = 20/80 overnight.
5. Prevent strong retained substances from remaining on the column. Strongly retained substances and macromolecular compounds accumulate in the column, causing additional retention behavior on the compounds in the sample, which not only causes peak broadening and tailing, but also reduces column efficiency. It also causes a change in retention time, which, when accumulated to a certain extent, also causes an increase in column pressure. Since the effect of strongly retained substances and macromolecular compounds on chromatographic separation is a cumulative effect, it takes a certain amount of time to be reflected, but for many drugs, especially complex samples, it is difficult to judge whether they contain strong retained substances, so To prevent the accumulation of strongly retained materials, the column needs to be cleaned with pure methanol or acetonitrile in daily routine maintenance. Clin-lab.com
cleaning method:
1. Unused buffer salt: After the analysis is completed every day, the buffer salt is removed by the above method, and then the column is back-washed with methanol or acetonitrile for 60 min.
2. Using buffered salt: After the analysis is completed, the buffer salt is removed by the above method, and then the column is washed back with pure methanol or acetonitrile for 60 min.
3. Remedy:
Water - acetonitrile - chloroform (or isopropanol) - acetonitrile - water The column was back flushed at a flow rate of 1.0 ml/min for 60 min each step.
(1) The pH of the mobile phase should be damaged by the pH of the mobile phase due to improper pH control of the mobile phase. It is usually difficult to recover the column, so it must be taken seriously and the PH value of the mobile phase should be strictly controlled.
(2) Removal of solid particles in the sample and mobile phase and solid particulate matter contained in the mobile phase can block the chromatographic sieve plate. Blockage of the sieve plate not only causes an increase in column pressure, but also causes a decrease in column efficiency. Because the clogging of the sieve plate will cause uneven liquid flow, resulting in tailing and widening of the chromatographic peak shape, thereby reducing the efficiency of the column. Therefore, it is recommended to use ultrapure water and chromatographically pure reagents to filter the sample before the sample is analyzed, and the mobile phase is passed through a 0.45 μm filter.
(3) The use of guard columns or in-line filter samples and mobile phase filtration does not completely eliminate solid particulate matter, as pump wear, seals and piping aging can also produce solid particulate matter, which is mobile phase Bring it into the column and block the sieve plate, causing the column pressure to rise and the column efficiency to decrease. Both the guard column and the in-line filter have sieve plates with the same pore size as the column pores, thus preventing solid particles from reaching the column and preventing blockage of the column. Since the increase in column pressure is a large percentage of analytical failures, it is recommended that you add a guard column or inline filter to the column injection end, in addition to filtering the sample and mobile phase.
(4) Correct use of buffer salt buffer salt is usually soluble in water, difficult to dissolve in organic solvents, so improper use of buffer salt will cause it to precipitate, block the pores between the filler matrix and the gap between the particles, so that the filler is knotted, column pressure Rising; at the same time hindering the free stretching of the bonded carbon chains on the substrate, reducing the retention capacity of the column and reducing the column efficiency. After the buffer salt is precipitated, removal is very difficult, so proper use of buffer salts is very important to extend the life of the column. The correct use of buffer salts can be attributed to one sentence: filter before use and rinse after use. The specific method is as follows:
1) Isocratic conditions: before and after using the buffer salt, the transition mobile phase should be washed at a flow rate of 1.0 ml/min for 60 min; another method of removing the buffer salt after use is to flush the column with a transient mobile phase at a flow rate of 0.2 ml/min. overnight.
2) Gradient conditions: Before running the gradient with the mobile phase containing the buffer salt, rinse the column with the same transient mobile phase as the initial mobile phase at a flow rate of 1.0 ml/min for 60 min, and then rinse the column with 1.0 ml/min of the transition mobile phase. 120min. The gradient setting of the buffered salt mobile phase should be as gentle as possible to avoid buffer salt precipitation during the gradient process.
(5) Prevent strong retained substances from remaining on the column. Strongly retained substances and macromolecular compounds accumulate in the column, causing additional retention behavior on the compounds in the sample, which not only causes peak broadening and tailing, but also reduces column efficiency. At the same time, it will also cause changes in retention time, and when accumulated to a certain extent, it will cause the column pressure to rise. Since the effect of strongly retained substances and macromolecular compounds on chromatographic separation is a cumulative effect, it takes a certain amount of time to be reflected, but for many drugs, especially complex samples, it is difficult to judge whether they contain strong retained substances, so To prevent the accumulation of strongly retained materials, the column needs to be cleaned with pure methanol or acetonitrile in daily routine maintenance.
Plant extracts refer to a class of substances derived from plants that have one or more biological functions. Can be separated by physical and chemical extraction of one or more effective components formed by natural products.
There are many kinds of plant extracts. At present, natural plant extracts mainly include essential oils, saponins, alkaloids, polysaccharides, polyphenols, flavonoids and so on. According to the biological activity, it can be divided into antioxidants: grape seed extract, green tea extract, pine bark extract, etc. Immune modulators: ginseng extract, gynostemma pentaphyllum extract, Ganoderma lucidum extract, etc. Improve cardiovascular function: ginkgo biloba extract, lotus seed heart extract, rhodiola extract, etc. Sedative: valerian extract, hop extract and so on.
According to their own characteristics in the market application of plant extracts can be roughly divided into six categories: coloring, seasoning, medicinal, health, dietary supplements and feed additives. Natural plant pigments refer to pigment components in roots, stems, leaves, flowers, fruits and bark of plants, such as turmeric, sappanwood, indigo, safflower, black bean and green walnut peel. Natural plant pigments are widely used in food, textiles, cosmetics, medicine, leather industry, printing and dyeing and other industries.
Plant extracts are rich in ingredients that can effectively stimulate the senses, such as sweeteners and volatile substances. Natural sweeteners, such as stevia glycoside and grosvenin, are popular new sweeteners. They are not only sweet, but also ideal substitutes for sucrose. Essential oils are concentrated volatile substances that are commonly used in the preparation of fragrances and are widely recognized in plant extracts.
Contained in the plant extracts of saponins, alkaloids, polyphenols, flavonoids and other ingredients are widely study has many biological activities, such as antioxidant, antibacterial, anti-inflammatory, improve animal production performance, antivirus, enhance immunity, etc., for human and animal health has the effect of nots allow to ignore, and the development of its pharmacology and health care function has become the main trend of plant extracts.In addition, as a dietary supplement, it is one of the main applications of various plant extracts. Such as oligosaccharides (oligosaccharides, oligosaccharides, oligosaccharides, galactose, etc.) dietary fiber, soybean protein, dietary fiber, wheat albumin, L-arabinose, sugar alcohol (xylitol, malt heavy sugar alcohol, sorbitol, etc.) and other natural plant food additives have been widely used in the food health care market. Many plant functional ingredients with anti-inflammatory, antioxidant and bacteriostatic properties are also commonly used as substitute anti-bacterial products. The application of green feed additives in livestock and poultry production has been vigorously developed, such as green tea polyphenols extract, pine bark procyanidins extract and polyanthocyanidins extract.
Due to the changes in lifestyle, working mode and consumption mode, more consumers are pursuing the life concept of "big health". The so-called "big health" refers to a concept of whole-process, comprehensive and total factor care for people's life around the basic necessities of life, life, old age, illness and death. It not only pursues individual physical and physical health, but also pursues mental, spiritual, social, environmental and family health. In the era of "great health", natural plant-based health products are the core and the key material basis.
With increasing attention to the food and drug safety, from natural plant in the development and utilization of the active ingredient is becoming more and more attention, a large number of food safety, have certain curative effect function of plant extracts have been used as raw materials in a variety of ways into functional food nutrition and health food has entered people's lives, and will play a more and more important role.
And more and more new research new discovery, predicts that the plant extract industry chain will have more members to join, there will be more business opportunities. The future domestic plant extract market will stride forward gradually to mature period!
Shaanxi Yingyuan Xingchuang Biotechnology Co., Ltd. is committed to plant extracts, advanced pharmaceutical intermediates, featured apis, and other customized research and development services; Relying on its GMP production base, it has set up a RESEARCH and development center and GMP pilot workshop to accelerate the commercialization process of production and research. The company has accumulated a number of invention patents, and has been declared by more than ten regulatory bodies such as China, FDA of the United States, EDQM of the European Union, India, Japan, South Korea and Australia. Please feel free to contact us.
plant extract,buy plant extract,wholesale plant extract,plant extract benefits,plant extract for sale
Shaanxi YXchuang Biotechnology Co., Ltd , https://www.peptidenootropics.com