1. When the handle is between Load and Inject, the flow path is temporarily blocked, causing a sudden increase in pressure in the flow path. When it is turned to the injection position, the excessive pressure causes damage to the column head. Therefore, the valve should be rotated as soon as possible and should not be stopped halfway. The syringe needle used in HPLC systems is different from gas chromatography and is a flat head syringe. On the one hand, the outer side of the needle is tightly attached to the inner side of the sealing tube of the injector, with good sealing performance, no leakage, and no introduction of air; On the other hand, it also prevents the needle from puncturing the sealing component and stator.
2Six way valve injection valveThere are two injection methods for the sample: partial liquid loading method and * liquid loading method. When using the partial liquid loading method for injection, the injection volume should be at least 75% of the volume of the quantitative ring. For example, for a 20gL quantitative ring, an additional 15pL of sample should be injected, and each injection volume should be accurate and the same; When using the liquid filling method for injection, the injection volume should be at least 3 to 5 times the volume of the quantitative ring, that is, a 20gL quantitative ring should be injected at least 60 to 1001aL of sample, in order to displace the residual solution in the quantitative ring and achieve the required precision and reproducibility. It is recommended to use a 100ul flat head injection needle combined with a 20ul full ring injection.
3. You can make your own quantitative ring according to the needs of the injection volume. Generally, it is not required to calculate the volume of the quantitative ring. For example, for a nominal 10gL quantitative ring, it is not important whether it is 9mL or 1lgL in reality, because the injection volume of the tested sample and the calibration sample are consistent, and errors are offset in the calculation results.
4. The sample injection requires no particles or substances that can block the needle and injection valve. The sample solution should be filtered through a 0.45~tm filter membrane. Prevent particles from blocking the injection valve and reduce wear on the injection valve. To prevent buffer salts and other residual substances from remaining in the injection system, the injector should be rinsed after each cycle, usually with a salt free diluent, water, or a salt free mobile phase. The load and inject positions of the injection valve should be repeatedly rinsed, and the outside of the syringe tip should be wiped clean with fiber free paper.