Autosampler maintenance
2020-08-26 12:13:04
Generally, the service life of the needle seat has a great relationship with the length of use and the number of times of use. I think it is difficult to say that it should be replaced regularly. The user still uses the frequency and time of his own instrument for reference and finds that the needle seat is leaking. It is good to change the liquid in time.
Autosampler maintenance
1. Parts wear
The wear of the autosampler parts includes the wear of the needle, the hub, the jaw sleeve, the metering pump, and the six-way valve rotor. Many people may understand and understand the wear of the needle seat. The joint between the needle seat and the needle is similar to the rubber material. The needle falls on the needle seat after the liquid is sucked, and the outer periphery of the pillow is closely combined with the rubber pad on the needle seat. Therefore, even when the system is subjected to a large pressure during the operation of the method, it is ensured that the mobile phase does not leak from the bonded portion. However, the needle seat also has a long life, and the needle is lifted up and down again and again, and the needle seat is sure to be worn. In addition, dust in the air falls on the needle seat, which will aggravate the wear of the needle seat. When the needle seat is severely worn, the rubber pad cannot be well sealed with the needle. When the system pressure is high, this part will leak. Generally, the service life of the needle seat has a great relationship with the length of use and the number of times of use. I think it is difficult to say that it should be replaced regularly. The user still uses the frequency and time of his own instrument for reference and finds that the needle seat is leaking. It is good to change the liquid in time.
When the needle is used for a long time, it will wear out. The wear of the needle is not as obvious as that of the needle seat. After all, the needle is made of metal, and the needle seat is similar to rubber. However, the needle will be hardened for one reason or another during use. The cap or the pinion causes the position of the needle to be not very positive. Such a needle will rub against the side wall of the needle seat during prolonged use, which will aggravate the wear of the needle seat. The needle with a serious positional deviation may be directly stuck. The hard metal of the needle seat causes the needle tip to be damaged or burrs. Such an autosampler finds that the needle seat leaks during use, but the replacement of the new needle seat will be broken by the needle in a few days. When you find abnormal wear of the needle holder, be sure to check the needle replacement in time.
After the autosampler has been used for a long time, there will be problems with the wear of the claw sleeve. After the claw sleeve is worn, the injection vial may not be grasped or the vial may be caught halfway. On the one hand, the wear of the claw sleeve is the cause of the rubber aging and normal wear and tear on the one hand. On the other hand, it is related to the use of the vial with the incorrect size. We have used the vial of Shimadzu chromatography for a while and found that the claw sleeve is worn. It is quite powerful, and it will be discarded later.
There is a metering pump on the autosampler. This part is relatively concealed. It usually does not require special maintenance. Few people will think about it. In fact, the metering pump is similar in structure to the front liquid pump. Plunger rod and sealing washer All are versatile, except that there is only one plunger rod. The wear of the metering pump is mainly the wear of the sealing gasket. The default configuration of the sealing gasket on the metering pump is the black sealing gasket used in reverse. We all know that the pump should be replaced with yellow when changing to normal phase. The positive phase special sealing gasket, in fact, the sealing gasket here is also replaced with the pump. When replacing the sealing gasket at this position, be careful. Unlike the pump, the user must first enter the diagnostic maintenance interface of the instrument, take the plunger rod in the metering pump back and remove the metering pump, otherwise the plunger rod will be removed. In a compressed position, it is troublesome to install. Compared with the plunger rod's active frequency of the infusion pump, the frequency of use of the metering pump is very low, almost as low as negligible, but this gasket is similar to wear. It is sometimes found that the position leaks when used for three or five years. , but the frequency of this problem occurs very low.
The wear of the six-way valve rotor is much higher than the wear frequency of the plunger rod, and the problem is also obvious. It is estimated that many people have removed the stator and rotor of the manual injector to study, the rotor of the autosampler is similar, the principle is the same. This rotor is said to be made of graphite and has a long service life. Especially when the mobile phase uses too much buffer salt, the rotor wears faster when there are many mechanical impurities in the mobile phase and the sample. A heavily worn rotor can't seal well with the stator, and it will leak at this time. Sometimes you find that the instrument with a long time is not allowed to make the external standard. When the same sample is taken continuously for many needles, the area of ​​the same injection volume is called the peak area. A=×σ×h=2.507σh=1.064Wh/2h>The peak area repeatability is very poor. Carefully observe the needle. When the needle is lifted from the sample bottle, the needle is suspended from the needle. At this time, it is necessary to consider replacing the rotor. The specific replacement method does not need to be described.
2. Mechanical failure
The mechanical failure mentioned here mainly refers to the problem on the robot arm of the autosampler. Careful observation of the movement of the injector arm during operation, mainly including horizontal and vertical, these movements rely on belts, gears and lead screws. carry out. The mechanical failure of the autosampler is mainly caused by dust in the air. The dust in the air is adsorbed on the belt, the lead screw and the gear, which increases the friction. In severe cases, the predetermined action cannot be completed, and even when the instrument is turned on, the sample is automatically injected. The self-test can not pass, the instrument can be turned off, and the clean fiber-free non-woven fabric can be used to wipe the screw, belt and gear transmission, and the belt can be pulled by the hand. Then wipe it again. If you have experience, you can disassemble the instrument case and wipe it. Be careful not to apply grease to the screw as it will increase the adsorption of dust. After rebooting, restart the instrument and try it out. Many times the problem can be solved. As for the more complicated positioning of the mechanical arm or the inability to grasp the vial, the special engineer came to the door for repair.
3. The needle seat is blocked
The problem of plugging the needle seat is believed to have been encountered by many people. Sometimes, the hard plastic vial cap is used accidentally or the sample pad on the cap is reused many times. When the syringe needle is tied down, it will The debris of the bottle cap or the bottle pad is sucked into the pinhole. After the needle falls onto the needle seat, the mobile phase flows through the needle seat through the 100ul loop, and the debris is brought to the needle seat inlet, causing the needle block to block and the system pressure. Too high or the needle seat leaks. After finding the problem, enter the instrument diagnosis interface, lift the needle, leave the needle holder, remove the front cover of the autosampler module, remove the screw connecting the needle holder to the six-way valve, forcefully remove the needle seat, and pour the needle seat Connected to the liquid pump, the flow rate is set to 5ml / min pressurization, the general blockage can be flushed immediately, if it can not be washed, the needle can be placed in the ultrasound system, then pumped, or Simply extend the pipeline and connect the pump to the ultrasonic. Once I even use the pump to punch the ultrasound and use the needle of the gas phase manual syringe to lick the needle inlet to finally get the plug inside. Then put it back and everything is ok.
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Editor: (Hardware Business Network Information Center) http://news.chinawj.com.cn
Autosampler maintenance
1. Parts wear
The wear of the autosampler parts includes the wear of the needle, the hub, the jaw sleeve, the metering pump, and the six-way valve rotor. Many people may understand and understand the wear of the needle seat. The joint between the needle seat and the needle is similar to the rubber material. The needle falls on the needle seat after the liquid is sucked, and the outer periphery of the pillow is closely combined with the rubber pad on the needle seat. Therefore, even when the system is subjected to a large pressure during the operation of the method, it is ensured that the mobile phase does not leak from the bonded portion. However, the needle seat also has a long life, and the needle is lifted up and down again and again, and the needle seat is sure to be worn. In addition, dust in the air falls on the needle seat, which will aggravate the wear of the needle seat. When the needle seat is severely worn, the rubber pad cannot be well sealed with the needle. When the system pressure is high, this part will leak. Generally, the service life of the needle seat has a great relationship with the length of use and the number of times of use. I think it is difficult to say that it should be replaced regularly. The user still uses the frequency and time of his own instrument for reference and finds that the needle seat is leaking. It is good to change the liquid in time.
When the needle is used for a long time, it will wear out. The wear of the needle is not as obvious as that of the needle seat. After all, the needle is made of metal, and the needle seat is similar to rubber. However, the needle will be hardened for one reason or another during use. The cap or the pinion causes the position of the needle to be not very positive. Such a needle will rub against the side wall of the needle seat during prolonged use, which will aggravate the wear of the needle seat. The needle with a serious positional deviation may be directly stuck. The hard metal of the needle seat causes the needle tip to be damaged or burrs. Such an autosampler finds that the needle seat leaks during use, but the replacement of the new needle seat will be broken by the needle in a few days. When you find abnormal wear of the needle holder, be sure to check the needle replacement in time.
After the autosampler has been used for a long time, there will be problems with the wear of the claw sleeve. After the claw sleeve is worn, the injection vial may not be grasped or the vial may be caught halfway. On the one hand, the wear of the claw sleeve is the cause of the rubber aging and normal wear and tear on the one hand. On the other hand, it is related to the use of the vial with the incorrect size. We have used the vial of Shimadzu chromatography for a while and found that the claw sleeve is worn. It is quite powerful, and it will be discarded later.
There is a metering pump on the autosampler. This part is relatively concealed. It usually does not require special maintenance. Few people will think about it. In fact, the metering pump is similar in structure to the front liquid pump. Plunger rod and sealing washer All are versatile, except that there is only one plunger rod. The wear of the metering pump is mainly the wear of the sealing gasket. The default configuration of the sealing gasket on the metering pump is the black sealing gasket used in reverse. We all know that the pump should be replaced with yellow when changing to normal phase. The positive phase special sealing gasket, in fact, the sealing gasket here is also replaced with the pump. When replacing the sealing gasket at this position, be careful. Unlike the pump, the user must first enter the diagnostic maintenance interface of the instrument, take the plunger rod in the metering pump back and remove the metering pump, otherwise the plunger rod will be removed. In a compressed position, it is troublesome to install. Compared with the plunger rod's active frequency of the infusion pump, the frequency of use of the metering pump is very low, almost as low as negligible, but this gasket is similar to wear. It is sometimes found that the position leaks when used for three or five years. , but the frequency of this problem occurs very low.
The wear of the six-way valve rotor is much higher than the wear frequency of the plunger rod, and the problem is also obvious. It is estimated that many people have removed the stator and rotor of the manual injector to study, the rotor of the autosampler is similar, the principle is the same. This rotor is said to be made of graphite and has a long service life. Especially when the mobile phase uses too much buffer salt, the rotor wears faster when there are many mechanical impurities in the mobile phase and the sample. A heavily worn rotor can't seal well with the stator, and it will leak at this time. Sometimes you find that the instrument with a long time is not allowed to make the external standard. When the same sample is taken continuously for many needles, the area of ​​the same injection volume is called the peak area. A=×σ×h=2.507σh=1.064Wh/2h>The peak area repeatability is very poor. Carefully observe the needle. When the needle is lifted from the sample bottle, the needle is suspended from the needle. At this time, it is necessary to consider replacing the rotor. The specific replacement method does not need to be described.
2. Mechanical failure
The mechanical failure mentioned here mainly refers to the problem on the robot arm of the autosampler. Careful observation of the movement of the injector arm during operation, mainly including horizontal and vertical, these movements rely on belts, gears and lead screws. carry out. The mechanical failure of the autosampler is mainly caused by dust in the air. The dust in the air is adsorbed on the belt, the lead screw and the gear, which increases the friction. In severe cases, the predetermined action cannot be completed, and even when the instrument is turned on, the sample is automatically injected. The self-test can not pass, the instrument can be turned off, and the clean fiber-free non-woven fabric can be used to wipe the screw, belt and gear transmission, and the belt can be pulled by the hand. Then wipe it again. If you have experience, you can disassemble the instrument case and wipe it. Be careful not to apply grease to the screw as it will increase the adsorption of dust. After rebooting, restart the instrument and try it out. Many times the problem can be solved. As for the more complicated positioning of the mechanical arm or the inability to grasp the vial, the special engineer came to the door for repair.
3. The needle seat is blocked
The problem of plugging the needle seat is believed to have been encountered by many people. Sometimes, the hard plastic vial cap is used accidentally or the sample pad on the cap is reused many times. When the syringe needle is tied down, it will The debris of the bottle cap or the bottle pad is sucked into the pinhole. After the needle falls onto the needle seat, the mobile phase flows through the needle seat through the 100ul loop, and the debris is brought to the needle seat inlet, causing the needle block to block and the system pressure. Too high or the needle seat leaks. After finding the problem, enter the instrument diagnosis interface, lift the needle, leave the needle holder, remove the front cover of the autosampler module, remove the screw connecting the needle holder to the six-way valve, forcefully remove the needle seat, and pour the needle seat Connected to the liquid pump, the flow rate is set to 5ml / min pressurization, the general blockage can be flushed immediately, if it can not be washed, the needle can be placed in the ultrasound system, then pumped, or Simply extend the pipeline and connect the pump to the ultrasonic. Once I even use the pump to punch the ultrasound and use the needle of the gas phase manual syringe to lick the needle inlet to finally get the plug inside. Then put it back and everything is ok.
Http://news.chinawj.com.cn
Editor: (Hardware Business Network Information Center) http://news.chinawj.com.cn
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