1. The pH of the mobile phase should be within the range of use. The pH range of the silica gel-based reversed-phase column is 2-9. The mobile phase exceeds the pH range, which will lead to the loss of the silica matrix and the carbon chain breakage of the bonded phase. The effect is reduced and the life is shortened.
Second, the removal of sample and mobile phase summary of the solid particle sample and the mobile phase containing solid particulate material will block the column sieve plate, not only will cause the column pressure to rise, but also cause the column efficiency to decline. Therefore, it is recommended to use ultrapure water and chromatographically pure reagents to filter the sample before analysis and the mobile phase through a 0.45um filter.
3. Use the guard column or the in-line filter guard column and the in-line filter to have a sieve plate with the same pore size as the column sieve plate, so that solid particles can be prevented from reaching the column, and the blockage of the column sieve plate can be effectively prevented. Since column pressure rise accounts for 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. Proper use of the buffered salt buffer salt may cause it to precipitate in the mobile phase (containing the organic solvent), block the pores between the filler matrix and the voids between the particles, cause the filler to be knotted, and the column pressure rises; The bonded carbon chain is free to stretch, the retention capacity of the column is reduced, and the column efficiency is reduced.
It is recommended to filter before use and rinse after use. The specific method is as follows:
1. Isocratic conditions: Before using the buffer salt, it is necessary to filter the mobile phase at a flow rate of 1.0 ml/min for 60 min.
2. Gradient conditions: Before running the gradient with the mobile phase containing the buffer salt, rinse with the same flow rate of 1.0 ml/min as the initial mobile phase for 60 min; after the analysis is completed, rinse with the filtered flow at 1.0 ml/min. The column was incubated for 120 min. The gradient setting of the buffered salt mobile phase should be as gentle as possible to avoid buffer salt precipitation during the gradient process.
Five, column cleaning method:
1. No buffer salt was used: After the analysis was completed every day, the column was backwashed with pure methanol or pure 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 back-washed with pure methanol or acetonitrile for 60 min.
Product Dimesnion: 6.18" x 4.13" /15.70cmx10.50cm
Mask Fabric Material: 5-ply material,100% polypropelyne
Ear Loop Material: 70% polyamide, 30% elastane
when to use: suitable for adults to use daily in a variety of settings such as home, outdoors and work
packaging: 5 pcs of mask in one sealed printed plastic bag to ensure hygiene or 10pcs per box
certification/standard: GB2626-2006(China KN95 standard) and FDA registered
about the manufacturer: Kapanou is china-based healthcare company
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