Ion chromatograph use note:

1. The filter head in the mobile phase bottle should always be below the liquid level to prevent the solution from drying out.

2. Before starting the pump, observe whether there are air bubbles in the pipeline from the mobile phase bottle to the pump, and if so, remove it.

The exclusion method is as follows: First, the plastic flow channel connector connected with the pump is screwed off, the deionized water is filled with the ear syringe, and injected from the flow channel tube connected with the pump segment, and the air bubbles in the flow channel tube are eliminated. Then raise the mobile phase bottle (usually a deionized water bottle) and connect the flow line connector to the pump. Start the pump, open the pump exhaust valve selection button, remove the air bubbles in the pump, generally observed as a more uniform effluent, and then tighten the pump exhaust valve. (Note: In this operation, the entire flow path is disconnected from the column)

3. When the entire flow path is cleaned with deionized water or mobile phase, large flow cleaning can be used (normally the flow rate can be set to 2.0 ml/min, but it can not be too big) to shorten the cleaning time, but in the flow-through phase chromatography Columns need to adjust the flow to the column flow conditions.

The operation is as follows: stop the pump first, then press the positive or negative sign, adjust the cursor to the flow position, press the enter key, and then adjust the flow to the column using the adjustment sign, and then press the enter key. At this point it is necessary to wait 5s before starting the pump switch. When connecting the column, first contact the column at the front end of the column for 2-5 seconds, remove the air bubbles from the front of the column, and then tighten the joint. After the solution flows out of the bottom of the column, screw the lower end of the column. (Note: The joints cannot be tightened too tightly to prevent the pressure of the system from increasing due to the tightness of the piping card. The degree of screwing is not to be leaky.)

4, using anion column detection, through the mobile phase, pay attention to the current knob to open, adjust to 90-100mA, after use to close the current knob.

5, when the injection valve should pay attention to the move, not too fast, so as not to damage the valve body; can not be too slow, so as not to cause sample loss. During the sampling process, the cleaning procedure must be strictly followed to reduce the influence of the previous sample residue on the test.

6, the maintenance of the instrument:

a, maintenance of the pump:

i. Before the instrument is used, water is used for 10-15 minutes to clean the pump and the entire flow path.

Ii. After each experiment is completed, water is allowed for 15-30 minutes, and the remaining mobile phase in the pump is cleaned. (Note: This step is very important, directly related to the normal use of the pump)

Iii. The instrument will not be used for a long time. Ionized water should be passed once a week. Used to replace deionized water in the pump that has spawned a small amount of microorganisms. If the deionized water is left for a long time, it will promote the reproduction of a small amount of microorganisms, and the microorganisms will easily adhere to the check valve in the pump.

b. Maintenance of the column:

i. Samples entering the column require pretreatment. The solid suspended solids, organic matter, and heavy metals in the sample are the three factors that affect the column efficiency.

Elimination of suspended solids: The sample is filtered using a 0.45 or 0.22 micron pore size microfiltration membrane.

Organic matter: Solid samples, whose detection components are relatively stable to high temperatures, can be detected by high-temperature ashing-elution or deionized water leaching.

The liquid sample can be digested with 22% hydrogen peroxide for 1.5 hours after microwave digestion to remove the organic matter and adjust the pH to neutrality for direct IC sample detection. (note the conversion between solution concentrations)

Heavy metals: Samples can be flowed through a cation exchange resin to remove heavy metals and directly injected into the sample.

Ii. High levels of constituents affect column efficiency.

Treatment of high Cl ˉ samples: The samples were injected through the Ag-treated column and injected or diluted for analysis after injection.

Treatment of high SO42ˉ sample: The sample was passed through the Bs treatment column and removed after SO42- injection or diluted for analysis.

Iii. After the experiment is completed, the column is sealed and stored with eluent.

c. Maintenance of suppressor:

When the negative ion eluent is turned on, the current knob is turned on, and there is no need to open the current knob when cation eluent or deionized water is passed.