How to maintain liquid chromatograph Shandong Luna

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How to maintain and maintain the liquid chromatograph? Shandong Lunan Ruihong company's Zhejiang Office

daily maintenance and maintenance

reservoir: cleaning is the key to maintain the normal use of the mobile phase reservoir. It is necessary to use HPLC grade solvents and reagents as far as possible, and the mobile phase containing buffer salt and non HPLC grade must pass 0.5 μ M to remove particulate matter. When changing the mobile phase, cross contamination should be prevented, and the old mobile phase and the long used reagent bottle should be discarded regularly to prevent the growth of microorganisms and the change of components. Some hydraulic operations in the reservoir are installed on the lower wall on the right side of the universal data testing machine frame, and the accessories inside should be cleaned regularly

pump: the sealing ring of the pump is the most easily worn part, and the damage of the sealing gasket can cause many faults of the system. It is suggested to replace the gasket every three months. But it can't be generalized. It depends on the material quality of the gasket, the use pressure is high, and the parameters required by the current spring are all small, maintenance and buffer solution. Take the following measures to extend the service life of the gasket:

1 wash the buffer liquid in the pump every day to prevent salt deposition, and immerse the pump in a buffer free solution or organic solvent

2 use HPLC grade reagents

3 use sintered stainless steel sinkers. Pay attention to prevent damage to the plunger rod or burning out the motor due to excessive pressure caused by pump blockage

Sampler: after shutdown, rinse the residual samples and buffer salts in the sampler with solvent to prevent inorganic salt deposition and sample particles from causing wear on the valve rotor surface or blocking 30 ~ 94hrg plugs. It is strictly prohibited to inject samples with a sharp needle like gas chromatography

chromatographic column: there are the following measures to prevent the decline of column performance:

1 the chemical corrosion of solvent should not be too strong

2 avoid particles settling in the stigma

3 a pressure limiter should be installed on the pump to prevent excessive pressure and impact

4 mobile phase pH> 7, use the same kind of filler with large particle size as pre column

5 sintered stainless steel filter is added to the column head, and protective column is added when necessary

detector: keep the detector clean and wash it together with the chromatographic column after use every day. It also includes many elements, such as the expansion of the control scope, the echo of the shopping mall, and the production cost. It is advocated to use strong solvent to backwash the detection tank irregularly (remove the column). Use the degassed mobile phase to prevent the air from getting stuck in the pool. The detector lamp has a certain service life. Do not turn on the lamp when not in use

operating limit: each pump has an upper pressure limit, and the system will automatically stop the pump when it reaches the predetermined value, which can protect the column and other hardware. The upper limit pressure is set below 20MPa, and the pump gasket and sample injection valve are durable, but the analysis time will be prolonged if the upper limit pressure is set too low. According to the inspection, the upper limit of pressure should be set at 15 ~ 20MPa. The pressure of the new column is relatively low, and the pressure rises as the service time increases, so the set upper pressure limit should also change. In gradient elution, the pressure change caused by the change of mobile phase should be considered to avoid pump stoppage due to low upper limit pressure. The system with microcomputer also needs to set the lower limit of pressure, which is generally 0.5 ~ 1MPa. The pump will automatically stop when the mobile phase in the reservoir is drained or seriously leaked. Sometimes the pump will stop automatically when the lower limit pressure is set to 0

Zhejiang Office of Shandong Lunan Ruihong Chemical Instrument Co., Ltd.



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