SOP for Atomic Absorption Spectrometer.

1.0       Objective:

               To provide written procedure for operation of Atomic Absorption Spectrometer.

2.0          Scope:

               This SOP covers operation of Atomic Absorption Spectrometer

3.0          Responsibility:

               Jr. Research Officer, Research Officer: Responsible for operation, calibration and maintenance of the instrument as per procedure.

               Head of Department: Responsible for calibration and maintenance, timely as per schedule.

               QA Officer/QA Manager: Review the records and governing the document.

4.0          Procedure:

4.1          Ensure that the instrument is clean and free from dust.

4.2          Operating Procedure:

4.2.1       Open the outlet of the acetylene cylinder supply.

4.2.2       Switch ‘ON’ the air compressor. The pressure must be 13-15 psi.

4.2.3       Switch ‘ON’ the computer system, monitor and the instrument.

4.2.4      Double click on the spectrAA icon or click on start menu, select programs and then select Varian AAS and SpectrAA.

4.2.5      After click on Worksheet icon load worksheet dialogue. Open new worksheet then give the name of worksheet and click ok.

4.2.6      Click on icon add methods and select the method. Place a Hollow Cathode Lamp as per selected method in a lamp holder positioned to the right of the instrument.

4.2.7       Click on icon Edit methods and open the dialogue box.  

4.2.8       Don’t use SIPS then Sampling Mode Manual, Measurement Mode, Integration Mode, Fill standard concentration and click OK.

4.2.9       Click Tab analysis and click on icon Optimize, select method and click OK. Then flame optimization windows open. Align the lamp up to maximum signal and click on optimize signals and click Inst. Zero then click OK.

4.3          Burner System:

4.3.1       Open the Burner door and confirm the standard acetylene burner head is installed.

               Close the burner door.

4.3.2      Setting the burner head (by turning the height control knob) lowers and upper side so that it is clear of the sample beam. Click on instrument zero. Slowly turn the burner height control knob counter until the absorbance display read zero again.

4.3.3       Very slowly turn the burner height control knob until the display read zero again.

4.4          Lighting The Flame:

4.4.1       Switch on the exhaust fan.

4.4.2       Push the flame ignite button located the front side of the instrument.

4.4.3       Ensure that the nebulizer uptake tube is placed into a blank solution or purified water whenever the flame is align.

4.5          Optimizing Instrument Performance:    

4.5.1       Allow the burner system to warm up for 2 minutes.

4.5.2      Aspirate the blank solution and press Inst. Zero button. Aspirate the known concentration of solution and locate the burner horizontal and vertical position for maximum absorbance reading.

4.5.3       Adjust the nebulizer for best sensitivity by firstly turning the nebulizer.

4.6          Analysis of Samples:

4.6.1       To open the main window of analysis, aspirate the Blank solution.

4.6.2       Click on icon start then asks prepare the instrument Zero click OK.

4.6.3       After click OK ask Present Solution CAL ZERO click OK.

4.6.4       After complete the blank ask for Standards, aspirate the standards then calibration curve is completed.

4.6.5       After complete the Calibration curve asks for sample aspire. After Sample aspire save the worksheet.

4.7          Procedure to Operate the VGA-76 Accessory:

4.7.1       VGA-76 Accessory attached the front side of AAS.

4.7.2     Check the current power supply. Connect the nitrogen cylinder and release pressure  about 4 Lb/in².

4.7.3     Connect the tubing with pump. First all 3 tubes wash with purified water for 20 – 30 minutes.

4.7.4       On the burner Head attached the cell stand and put the cell.

4.7.5       Connect the cell with VGA-76 with rubber tube.

4.7.6       Before Analysis the one of the last two tubes put in Acid Container and other tube put in Reductant Container. Third tube put on the blank solution.

4.7.7     To start the analysis the sample tube put in the blank, after the Blank the tube put in standard, After the standard Calibration Curve Completed the tube put in sample.

4.7.8       After the analysis the sample, tube put in the water for washing.

4.8          Shutting Down the VGA-76 Accessory:

4.8.1     After the analysis all tubes put in water for washing. Continue the washing for 20-30 minutes. After washing the tubes disconnect from the pump.

4.8.2     Close the Nitrogen Cylinder and disconnect it. The VGA-76 Accessory Remove from AAS.

4.9          Shut Down Procedure:

4.9.1     With the flame still burning, aspirate the correct rinsing solutions in the sequence listed below to rinse the nebulizer and burner.

4.9.2       If used aqueous solutions during the analysis aspirate purified water for 2 minutes.

4.9.3       Push Flame off button located on front side of the Instrument.

4.9.4       Turn off the gas supplies to the Spectrometer.

4.10        Report:

4.10.1     For report double click on the spectrAA icon, click on icon reports. Open the window of

               Worksheet then click next, select solution data, report contents, calibration graphs etc.

4.10.2     Then click next then report is generated, to see the report click on print preview or print out the report click print report.

4.11        After completion exit the soft ware and switch off the instrument.

4.12        Record the usage of instrument in instrument usage log book (Annexure - 1).

5.0          Precaution:

5.1          COMPRESSED GASES SHOULD ALWAYS BE HANDLED WITH CARE. To avoid leaks, periodically check the lines and fittings. Use soap water to check leaks.

5.2          Acetylene, in its free state under pressure may decompose with explosive violence,therefore NEVER EXCEED A PRESSURE OF 100 kPa [ 15 psi].

5.3          NEVER USE OXYGEN OR OXYGEN-ENRICHED AIR, AS AN INSTANT  FLASHBACK WILL RESULT.

5.4          Do not touch the quartz lamp envelope with bare hands. Skin oils may be adsorbed into   the quartz. Always use clean cotton gloves when handling lamps. If contact is made with the lamp surface, clean immediately with propanol or equivalent.

5.5          The liquid trap MUST be filled with the same solvent as that used for the analysis.

5.6          Always allow a burner to cool before removal.

5.7          Do not manually move the arm of the flame sampler as this may damage the drive  mechanisms.

5.8          Do not leave uncovered containers of volatile organic solvents near the naked flame.

5.9          Do not store solvent in the vicinity of the atomic absorption spectrometer.

5.10        Ventilate the working area by using an efficient extraction system to remove burnt gases    and toxic compounds that may be formed.

6.0                    Routine maintenance:

6.1                    Clean the instrument with dry cloth

6.2                    Clean the burner with burner cleaning card.

6.3                    Check the hoses and plumbing of gases for leaks.

7.0          Documentation:

7.1          Annexure – 1    Instrument Usage logbook.               XXX/FRM/000

8.0        History of Revision:

Revision No.	Effective Date	Revision details	Reason for revision

Annexure - 1
Date	Name of Sample	A. R. No.	Batch No.	Analysed by	Remarks
SOP No. : XXX/SOP/000-00                                Format No. : XXX/FRM/000-00