To lay down the procedure for operation and calibration of Metrohm-761 compact IC.
PURPOSE:
1.1 To lay down the procedure for operation and calibration of Metrohm-761 compact IC.
2.0 SCOPE:
2.1 This procedure is applicable in Quality Control department.
3.0 RESPONSIBILITY:
3.1 Junior Assistant/Senior Assistant – QC
3.2 Senior Executive – QC
4.0 ACCOUNTABILITY:
4.1 Manager – QC
4.2 Asst. Manager – QC
5.0 GENERAL PROCEDURE FOR CONDITIONING THE SYSTEM:
5.1 Prepare the appropriate mobile phase and fill the same in the bottle.
5.2 To start with connect the tubing in the following way.
Mobile Phase IC Pump?Purge Valve on the IC Pump?In-line Filter?Pulse Dampener?Injector Valve?Dummy Connector?Detector Block?Waste Bottle.
5.3 Switch on the PC first and then the Compact IC Instrument.
5.4 Double Click on the 761 IC Icon to open the Software. Click?Log in.
5.5 Go to File/Open/System. Choose the desired system (Suppressed action/ Cation / Non-suppressed action) by clicking on it and Click Open. Then select the method by clicking on it and Click Open. A system Window appears with Instrument Icon. Go to Control?Connect to Workplace and Click it. The software and Hardware are connected and the status is displayed in the system state window.
5.6 Double Click on the 761 Compact IC Icon in the system window. A window is displayed with Conductivity and Pressure display.
5.7 Select a flow rate 0.2 mL/min. Click ‘Send to Unit’. Click Save. Click on button of the pump given in this window. Wait till the pressure reading stabilizes. Increase the flow rate to 0.4 mL/min. Click ‘Send to Unit’. Click Save. Wait till the pressure reading stabilizes. This way increase the flow rate gradually to 1.0 mL/min. Check for any leakages in the connections and set it leak proof.
5.8 Run the pump until a stable Conductivity value is displayed. The system is conditioned.
5.9 Gradually decrease the flow rate of the pump. Every time, after changing the flow rate, we have to click ‘Send to Unit’ and then click Save. This way decrease the flow rate to 0.2 mL/min and click Off button of the pump. This stops the pump.
6.0 PROCEDURE FOR CONDITIONING THE COLUMNS:
6.1 Connect the Guard column, Separating Column (Suppressor in the case of anion Analysis) in the place of Dummy Connector and make the connections as in Point 2 of General Procedure for conditioning the System.
6.2 Repeat points 6 to 8 of General Procedure for conditioning the System. Now the Column is also conditioned.
7.0 PROCEDURE FOR ANALYSIS:
7.1 Go to Control/Start Determination. A white Chromatogram window opens with a message – Measure Baseline on its left top corner. Go to Method/passport. Give the file name and duration time as per STP. Go to Sample menu and click it. Fill the parameters as required. Go to Column menu and click it. Fill the parameters as required. Go to Eluent menu and click it. Fill the parameters as required. Click Apply and click OK.
7.2 After the Baseline Stabilizes which is an indication of Stabilization of the Column denoted by stable Conductivity reading, analysis can be started.
7.3 Go to Method menu and click on System. System window appears. Double Click on the 761 Compact IC Icon in the system window. A Window is displayed with Conductivity and Pressure display.
7.4 Set the flow rate for diluent as per STP by increasing or decreasing it Gradually as per the procedure given above.
7.5 Keep the injecting tube in diluent. In valve buttons given in the window click Fill. Then Click Inject.
7.6 The Chromatogram window changes color with the message – Measure on the left top corner. Go to Method/passport. Give the file name and duration time as per STP. Go to Sample menu and click it. Fill the parameters as required. Go to Column menu and click it. Fill the parameters as required. Go to Eluent menu and click it. Fill the parameters as required. Click Apply and Click OK.
7.7 If the determination is over, a white Chromatogram window opens with a message – Measure Baseline on its left top corner. Wait for stabilization of the baseline.
7.8 After the Baseline Stabilizes, Go to Method menu and click on System. System window appears. Double Click on the 761 Compact IC Icon in the system window. A Window is displayed with Conductivity and Pressure display.
7.9 Set the flow rate for Standard as per STP by increasing or decreasing it Gradually as per the procedure given above.
7.10 Keep the injecting tube in Standard solution. In value buttons given in the window click Fill. Then Click Inject.
7.11 The Chromatogram window changes color with the message – Measure on the left top corner. Go to Method/passport. Give the file name and duration time as per STP. Go to Sample menu and click it. Fill the parameters as required. Go to Column menu and click it. Fill the parameters as required. Go to Eluent menu and click it. Fill the parameters as required. Click apply and Click O.K.
7.12 If the determination is over, a white Chromatogram window opens with a message – Measure Baseline on its left top corner. Wait for stabilization of the baseline.
7.13 Repeat steps 6.10 to 6.12 as many times as standard is to be injected as per STP.
7.14 Keep the injecting tube in Sample Solution. In valve buttons given in the window click Fill. Then Click Inject.
7.15 The Chromatogram window changes color with the message – Measure on the left top corner. Go to Method/passport. Give the file name and duration time as per STP. Go to Sample menu and click it. Fill the parameters as required. Go to Eluent menu and click it. Fill the parameters as required. Click Apply and Click O.K.
7.16 If the determination is over, a white Chromatogram window opens with a message – Measure Baseline on its left top corner. Wait for stabilization of the baseline.
7.17 After the final analysis for the day is over, flush the column for 20 minutes – a dry run as it should not contain any ion when it is stored. Then reduce the flow rate of the pump gradually and finally stop the pump.
7.18 Remove the column and connect a dummy connector in the place of the column. Fix the end caps of the column properly and keep is safely.
8.0 PROCEDURE FOR CALIBRATION QUANTIFICATION OF SAMPLE:
8.1 Go to File/open/chromatogram and click it. Chromatogram open window appears. Choose the lowest Standard Chromatogram by clicking it from the list and Click OK. The chromatogram appears on the screen.
8.2 Go to Method/Integration and click. Integration parameters properties window appears. Fill the parameters as per requirement. Click Events. Another window appears. Fill the RT in time filled and Selected the event from list and Click OK. By this way integrate all the peaks and save the chromatogram.
8.3 Go to Method/Calibration/ Components and click it.
8.4 Click Add repeatedly according to number of components present in the standard.
8.5 Name the components according to their retention time in the Name field.
8.6 Go to Concentration – enter the concentration units and data type in their respective fields – e.g., ppb or ppm as units. Click Add in the Levels part of the window. Click OK.
8.7 Click Calibrate in the Levels part of the window. Click OK.
8.8 Click OK. Go to Graphs and check the calibration graph. Click OK. Click Ok. Again.
8.9 Right Click the mouse on the chromatogram and go to Appearances/Labels. Select the component name and quantity.
8.10 The respective component name and quantity are displayed.
8.11 Go to Method/Calibration/Save to method. A window appears whether to save the Calibration or Not. Click YES.
8.12 Close the chromatogram window. A window appears whether to save the changes or Not. Click YES.
8.13 Another window appears whether to overwrite the chromatogram or Not. Click YES.
8.14 Another window appears whether to save the changes to Method or Not. Click NO. Now the appropriate Standard is calibrated.
8.15 For quantification of sample, Go to File/open/chromatogram. Chromatogram open window appears. Select the sample chromatogram by clicking on it and make necessary changes in the integration parameters as explained above for the integration of standard. Go to Method/Calibration/Load from method.
8.16 Double click on the sample Chromatogram. The sample is quantified and respective concentrations are displayed. Save the Chromatogram.
8.17 For reading the report, choose the Chromatogram. Go to Process/Make report. Select the destination (e.g. printer, screen etc.) in the destination field and then Click report. The report is displayed. Give print command and take print out.
9.0 PROCEDURE FOR INSTRUMENT CALIBRATION:
9.1 Checking the flow rate of the pump:
9.1.1 The flow rate of the pump is checked by collecting the eluent in a graduated and tared 10 ml measuring cylinder at the detector outlet for 5 minutes. This is done by setting the three different flow rates, one being 1.0 ml flow rate the chosen system and other two being 0.5 ml flow rate and 1.5 ml flow rate. The collected eluent is weighed. Three readings are taken for each flow rate and the average is used for calculating the actual flow rate. The average weight is converted to mL/min. by assuming the density value as unity.
9.1.2 Requirements: The variation between the displayed and the actual flow rate must not exceed ±3%.
9.2 Linearity of the calibration curve:
9.2.1 Flow following parameters are set on the compact IC:
Full scale : 50 μS/cm
Temperature : 35°C
Flow rate : Normal flow rate of the chosen system
Mobile phase : 1.7 mM NaHCO3 + 1.8 mM Na2CO3
9.2.2 A multi-element standard solution of Chloride, Nitrate and sulphate of three different concentrations namely 2,5 and 10 ppm are prepared for this purpose. Each of the standards are injected twice. The chromatograms for each injection is recorded and assessed for linearity.
9.2.3 Requirement: Correlation coefficient (R2) should be ? 0.998.
9.3 Reproducibility:
9.3.1 The following parameters are set on the Compact IC:
Full Scale : 50μS/cm
Temperature : 35°C
Flow rate : Normal flow rate of chosen system
Mobile phase : 1.7 mM NaHCO3 + 1.8 mM Na2CO3
9.3.2 The reproducibility of the injection system is checked by 5 injections of a multi-element standard solution of chloride, nitrate and sulphate (10 ppm). The chromatograms for each injection is recorded and assessed for reproducibility (expressed by the RSD of both retention time and peak areas).
9.3.3 Requirement: The RSD for the peak areas and the retention time should ? 2%.
9.4 Checking the conductivity detector:
9.4.1 The column and the suppressor are disconnected from the system. The injector valve is connected to the conductivity detector with a dummy connector. The following parameters are set on the Compact IC.
Full scale : 1mS/cm
Temperature : 35°C
Flow rate : 1mL/min
Cell constant : as given on the detector block
(if nothing is given then the default value is 16.7)
9.4.2 The line is flushed with 20% methanol in Millipore water for 10 minutes.
9.4.3 Then the conductivity standard solution, 0.005M potassium chloride solution is passed through the detector block. The stable reading (change of conductivity is 2μS/cm per minute is noted.
9.4.4 Flush the line again with 20% methanol in Millipore water till the conductivity comes below 5μS/cm.
9.4.5 Requirement: The conductivity value should lie in the range 580 to 780 μS/cm.
9.5 Calibration frequency: Once in 6 months.
Compact ic, metrohm, pulse dampener, injected twice, chloride, baseline
