Availability and Specification of Flash Column
In environmental analysis and testing, flash column (such as Spherical Phenyl Flash Column, Irregular C18 Flash Column, Spherical C8 Flash Columns) is widely used in the pretreatment of samples, such as the organic pollution analysis of water and aerosols, the extraction solution is transferred to the chromatographic column, then the alkane part is eluted with cyclohexane, the polycyclic aromatic hydrocarbon pollutants are eluted with benzene, and the polar components are eluted with ethanol. In soil analysis, rare earth elements thorium, thallium, and so on are separated by the alumina column.
Analysis Process
Adsorption column chromatography usually fills glass tubes with large activated porous or powdered solid adsorbents. When the mixture solution to be separated flows through the adsorption column, various components are adsorbed at the upper end of the column at the same time. When the eluent flows down, because of the different adsorption capacities of different compounds, the speed of downward eluting is also different, so different levels are formed, that is, the solute forms a number of ribbons from top to bottom in the column according to the affinity to the adsorbent. When eluted with solvent, the separated solute can be washed out and collected from the column.
Chemical Properties of Flash Column
Hawach flash column specifications include two aspects: column length and column inner diameter. The selection of column specifications directly affects the analysis speed, separation ability, detection ability, and solvent consumption for each analysis. For the same analysis time and separation degree: the column with a large inner diameter consumes more solvent than the column with a small inner diameter. Smaller inner diameter columns also require fewer samples for the same detection signal. Therefore, small inner-diameter columns can be used when the sample size is limited. The long column can give a high degree of separation, and the short column can provide rapid separation. We can choose the appropriate chromatographic column according to the sample situation.
Physical Properties of Flash Column
The high surface area has strong retention, column capacity, and separation degree for the separation of multicomponent samples. Fillers with low surface area usually reach equilibrium quickly, which is particularly important for gradient eluting. The smaller the average particle size, the smaller the particle distribution, the higher the chromatographic column efficiency, and the higher the backpressure.
Availability of Flash Column
When the basic molecule (pyridine) was analyzed at high pH, the column effect, peak trailing, and retention difference could be observed. This indicates that there is still an unwelcome secondary interaction between the basic molecules and the silicone groups on the surface of the stationary phase. After medium pH comparison, when alkaline molecules (pyridine) were analyzed at high pH, the Hawach flash column once again provided excellent peak shape and column effect, indicating that the unpopular secondary interaction had been almost eliminated. These adverse interactions may also lead to poor reproducibility of chromatographic columns. Changing pH is a powerful tool to optimize selectivity and identify sample impurities.
Specification of Flash Column
Hawach flash columns are designed to provide excellent peak shape and life in LC/MS compatible acidic, neutral, and alkaline pH buffers, and can be used in conjunction with mobile phase containing methanol or acetonitrile without reducing column efficiency or prolonging equilibrium time. The super lazy flash columns with extended pH stability for UHPLC and HPLC selective LC/MS compatible buffers between pH 1.5 and 11.5 at low, medium, and high pH conditions, and the best performance and reproducibility can be obtained.
A typical flash column for chromatography is made of stainless steel or glass, with a length of 10-30 cm and a diameter of 2.5-7 cm. It contains a stationary phase with 30-50 μm particle size, usually silica gel. The column operates at low pressures (<100 psi) and high flow rates. It must be compatible with the solvents used and have standard connectors for chromatography systems. The column should also be chemically resistant and have end caps to prevent leakage. Always follow manufacturer guidelines for packing and use.
