To provide a procedure to operate and Calibrate the spectrophotometer xxxxx (Perkin Elmer, Spectrum one).
I. PURPOSE :
To provide a procedure to operate and Calibrate the spectrophotometer xxxxx (Perkin Elmer, Spectrum one)
II. SCOPE:
This procedure is applicable to the FTIR Spectrometer (Perkin Elmer) used in the Quality Control department
III. RESPONSIBILITY:
It is the responsibility of the Quality Control personnel involved in the calibration of FTIR Spectrometer (Perkin Elmer) to follow the procedure and schedule as mentioned in this Standard Operating Procedure
IV. DOCUMENT REFERENCE:
SOPs : Core procedure, Calibration of Equipment
Operation of KBr Pellet Press
Forms : Calibration of FTIR Spectrometer
V. OPERATION:
1.0 General
1.1. Before use, ensure that the instrument is clean and free from dust. Ensure that the instrument
is connected to a stabilized ( U.P.S. ) power supply.
1.2 Avoid touching optical surfaces.
1.3 Do not carry out operations involving water or corrosive liquids near the instrument.
1.4 Ensure that the instrument is located and maintained at a temperature between 19°C and 30°C and at a relative humidity not exceeding 60 percent.
2.0 STARTING UP:
2.1 Connect the instrument to the main power supply.
2.2 Switch on the instrument using the switch provided on the right side of the instrument.
2.3 Switch on C.P.U., Monitor . Wait to start Windows software.
2.4 Double Click on Spectrum one icon on the main screen.
2.5 Select ‘Spectrum One’ and click ‘OK’. Click BACKGROUND, background will be stored automatically, and then click ‘OK’.
Note : The instrument is always kept ON to get optimum performance.
3.0 CHECKING ENERGY LEVEL
3.1 To see the energy level click “Instrument” from menu bar and then click “Monitor”.
3.2 Wait till the energy level is displayed on the monitor. It must be more than 2500.If the energy is less than 2500, then the instrument hould not be used and Service engineer should be called.
3.3 [If current intensity is displayed as ‘0000’ or the error ‘Scan failed – Source failed’, is displayed on the screen, this indicates that the source filament needs to be replaced.]
3.4 Click “ Exit “ to come out of the test mode.
[Note: Perform this test whenever the power is switched off and put on again]
4.0 TAKING BACKGROUND SPECTRUM
4.1 Ensure there is no sample in the sample compartment.
4.2 Go to SET UP => INSTRUMENT & fill the following informations.
4.3 Click SAMPLE => Type name (Background) SCAN => Background UNIT => Energy (EGY). RANGE => Start: 4000 cm-1 End: 400 cm-1, SCAN NO=> 4. Click Apply & then scan.
4.4 A blank background scan is done and automatically stored.
5.0 STANDARD AND SAMPLE PREPARATION IN POTASSIUM BROMIDE (KBr)
5.1 Make sure that the pestle mortar and the pellet maker used for preparing KBr disk is clean, if it is not, clean it.
5.2 Weigh 4 to 5 mg of the standard in a mortar and grind the standard until it takes a glossy appearance.
5.3 Weigh 400 to 500 mg of KBr into the same mortar so that the concentration of standard is about 1 % (For 5 mg standard take 500 mg of KBr).
5.4 Grind the standard thoroughly to get a uniform mixture unless otherwise specified in the specification.
5.5 Assemble the die by inserting the shiny stainless steel disc into the barrel with the polished side up.
5.6 Take care not to touch the polished surface.
5.7 Transfer the powder from mortar into the barrel using a spatula and rotate the assembly such that a thin uniform surface is obtained. Insert the plunger.
5.8 Place the die assembly in hydraulic, press and rotate the screw on top clockwise until it holds the die assembly tightly.
5.9 Close the pressure valve and apply by moving the lever up and down. Apply to 10 tons pressure and wait for 2 minutes.
5.10 Release the pressure gently by opening the valve.
5.11 Separate the barrel from the base and place the barrel with the plunger on the hydraulic press such that the plunger is touching the base of the hydraulic plate. Place the disc removed over the top and rotate the screw on top clockwise till the disc comes out.
5.12 Place the KBr disk in the sample holder.
5.13 Carry out same procedure for the sample preparation.
6.0 STANDARD AND SAMPLE PREPARATION IN NUJOL (Mineral oil / Liquid paraffin oil)
6.1 Weigh about 10 to 20 mg standard into a mortar.
6.2 Grind the standard thoroughly to get a glossy appearance unless otherwise specified in the specification.
6.3 Add two drops of nujol (liquid paraffin of spectroscopic grade is suitable) and mix thoroughly to get a uniform smooth creamy consistency.
6.4 Collect this mull from the mortar and place it on a NaCl window cell (previously cleaned in carbon tetrachloride).
6.5 Place the second window on top. Lightly press the two windows together so as to get an evenly spread layer of sample between the NaCl windows. Wipe away the NaCl cells with excess split mull with a soft tissue paper and place in the cell holder and tighten lightly.
6.6 Carry out the same procedure for the sample preparation.
7.0 TO OBTAIN A SPECTRUM
7.1 Keep the holder containing the pellet in the sample compartment and close the compartment.
7.2 Go to SET UP => INSTRUMENT & fill the following information
7.2.1 Click SAMPLE =>Type Sample Name Description =>About sample (About AR No.)
Click SCAN => Select Sample UNITS => % T
RANGE => Start : 4000 cm-1 End : 500 cm-1
SCAN NO => 4. Click Apply & then scan.
7.2.2 Click Instrument
Resolution: Select 4.00
7.2.3 Click Beam
Select None.
7.3 TO GIVE THE CORRECT PATH.
Go to beam and click on filter. select none
While performing internal calibration select polystyrene filter.
Instrument will scan the spectrum & will be displayed on the screen. If needed smooth the spectrum in seq, Go to PROCESS=>SMOOTH=>AUTOMATIC SMOOTH
7.4 Similarly obtain the spectrum of related working standard material.
8.0 SUPERIMPOSING TWO SPECTRA
8.1 Select the Raw material spectrum & related WS spectrum from C:Pel_dataspectraws and click ‘OK’
9.0 OPTIMUM GRAPHICS DISPLAY
9.1 Select one of the spectra & adjust using arrow keys on the screen.
9.2 To mark the peaks of interest select VCURSR => drag to desired peak and double click.
9.3 To remove the vertical line click VCURSR again.
10.0 PRINTING
10.1 Click setup and then Report Template. A Report Builder opens on the main screen. Click ‘File’ and then ‘Open Template’. Open the template ‘HET.pfm’.
10.2 From the main screen click ‘File’ and then ‘copy to report’. The spectrum gets copied to the ‘HET’ Report Template. Give print from the Report Builder print option.
10.3 Close the Report Builder icon.
11.0 Maintenance:
11.1 Change the purge desiccant kits after every six months to control the humidity inside
the instrument, failing which can cause extensive damage to the hygroscopic parts.
11.2 While operations dehumidifier must be kept on.
12.0 Assembling and application of HATR accessory:
12.1 Raise the sample cover to the vertical position, press the release clip and lift the cover upwards
as shown in the figure given below.
12.2 Reach in under the base of current accessory and pull the blue release towards you to release the accessory.
12.3 Hold the HATR accessory as shown in the figure given below, rest the back of it on the
ledge in the sample area and slide it into the position
12.4 After assembling the HATR accessory, software will recognize, and displays the message
“ Ensure top plate in position’.
12.4 Remove the cover and place the Zinc selenium sulphide plate on the HATR accessory, with arrows pointing towards the back.
12.5 Collect the new background scan and place the sample on ZNS plate and place the cover on it.
12.6 Apply the force by using force gauge screw and adjust the screw to 60% force and then proceed for sample scan.
13.0 Qualification of KBr
13.1 Check the surroundings for cleanliness or if it is not clean, clean with soft clean
duster.
13.2 KBr bottle should be stored in dry box.
13.3 Scan of KBr should be taken after opening the bottle to check any interfering
absorption bands. Note the lot number of the bottle and give the validity period of
3 years on the bottle.
13.4 Make a disc about 2 mm thick from material.
13.5 Set measuring mode absorbance.
13.6 Place the KBr pellet inside the interferometer and give background scan.
13.7 Do not remove the KBr pellet. Then given sample scan.
13.8 Acceptance Criteria: The spectrum should have a substantially flat baseline over
the range 4000 to 620 cm-1. It should exhibit no maxima with an absorbance
greater than 0.02 above the baseline with the exception of maxima due to water at
3440 and 1630 cm-1 .
VI. CALIBRATION Calibration frequency: First week of every month
1.0 Control of Wave numbers:
1.1 Record the spectrum of polystyrene film4000 cm-1 to 650 cm-1 after the routine
Background correction. The film should be stored carefully in desiccator over silica gel
when not in use.
1.2 The following bands should appear at the frequencies indicated below and should not deviate from the designated frequency by more than the tolerance indicated.
S.No. Wave-number (cm-1) Acceptable Tolerance (cm-1)
01. 3060.0 ± 1.0 (3059.0 –3061.0)
02. 2849.5 ± 1.0 (2848.5 – 2850.5)
03. 1942.9 ± 1.0 (1941.9 – 1943.9)
04. 1601.2 ± 1.0 (1600.2 – 1602.2)
05. 1583.0 ± 1.0 (1582.0 –1584.0)
06. 1154.5 ± 1.0 (1153.5 – 1155.5)
07. 1028.3 ± 1.0 (1027.3 – 1029.3)
2.0 Control of resolution performance:
2.1 Expand the recorded polystyrene spectrum in the region 3200 cm-1 to 2600 cm-1 as follows : Go to “ FORMAT “ icon , enter 3200 in LEFT block, 2600 in RIGHT & click OK .
2.2 Note down the absorption at wave numbers 2870 cm-1 (tolerance ± 1 cm-1) and 2849.5 cm-1 (tolerance ± 1 cm-1). The difference of between the absorbances at the absorption minimum at 2870 cm-1 and absorption maximum at 2849.5 cm-1 should be greater than 0.33.
2.3 Expand the polystyrene spectrum in the wave number region 1800 cm-1 to 1400 cm-1 cm-1 as follows: Go to FORMAT icon, enter 1800 in LEFT block, 1400 in RIGHT & Click OK.
2.4 Note down the absorption at wave numbers the difference the absorption at 1583 cm-1 (tolerance ± 1 cm-1) and 1589 cm-1 (tolerance ± 1 cm-1). The difference of between the absorbances at the absorption maximum at 1583 cm-1 and the absorption minimum at 1589 cm-1 should be greater than 0.08.
3.0 Io-line Flatness test:
3.1 Scan the background from 4000 cm-1 to 650 cm-1 after the routine Background correction. adjust the Y axis to 99.5% - 100.5% transmittance.
3.2 Acceptance criterion: The Io -line should not cross 99.5% and 100.5% transmittance range.
Note: If the instrument fails in calibration, proceed as per the Core Procedure, “Calibration of Equipment”.
Ftir, spectrophotometer, pellet press , automatically, barrel
