TCNJ Chemistry Instrumentation

Operating Instructions

Diffuse Reflectance Accessory

Monitoring the Energy of the RX-1 FTIR Instrument

1) Hit the blue Setup key on the keypad. Seven grey "buttons" will appear at the bottom of the computer screen. Select the grey button on the keypad corresponding to Others (second button from the right).

2) Select the grey button on the keypad corresponding to Others again (second button from the right). Select the button corresponding to Test (second button from the right).

3) Select the grey button on the keypad corresponding to Adjust (second button from the right). Select the button corresponding to Energy (fourth button from the right).

4) The infrared laser energy value will appear on the screen, along with a black bar. Make sure the energy is roughly 90 or more. Take note of the energy value because it will be used later.

Installing the Accessory

1) Before you install the accessory, turn it around and look at the bolts on the back. These bolts hold mirrors in place on the inside of the accessory. Pay special attention to the bolt marked with the colored sticker. This is the only bolt you will need to adjust after you install the accessory. Do not touch any of the other bolts!

2) Open the sample compartment of the instrument. If there is a sample holder for salt plates present, remove it. Also remove the light grey platform from the bottom of the sample compartment (looks like a small shelf that is about 5"x7").

3) Slide the accessory into the slots at the bottom of the sample compartment, making sure to push the accessory as far back as it can go.

Checking the Operation of the Accessory

1) Look at the sample holder. The sample holder can hold two pans, sticks, or pads. The small holes are for the sticks. The deep wells are for the pans. The slight indentations are for the pads. On the side of the sample holder, you will see a large groove.

2) Hold the sample holder in your right hand so that your thumb is in the large groove and the slight indentations are facing up. The outermost indentation on the sample holder (furthest away from you) is for the reference pad. A reference pad should already be on the holder, possibly with its edges cut off. If a pad is not present, peel a coated abrasive pad off of the sheet and stick it on the holder, lining it up with the edge of the outermost indentation.

3) Slide the sample holder into the accessory. Push the sample holder into the accessory as far as the first click.

4) On the computer screen, you should still see the energy value of the infrared laser. (If not, go back to the beginning of these instructions to monitor the energy.) The energy value should be roughly 10-15% of the original value (before the accessory was installed).

5) Maximize the energy throughput by slightly turning the bolt marked with the colored sticker using your fingers (no wrenches!). When the accessory is installed, this is the bolt that is on the left side nearest to the top. The energy value will increase or decrease significantly with very small adjustments, so the bolt does not need to be turned much at all.

6) When the energy value reaches a maximum, slowly turn the focus knob on the front of the accessory clockwise or counterclockwise in order to further maximize the energy throughput. Do not turn the focus knob so much that it falls out of the sample accessory!

7) Hit the red Cancel button until you reach the main screen. The instrument will beep angrily at you.

Collecting Spectra Using Abrasive Pads

1) Remove the sample holder from the accessory. Make sure the reference pad is still in place (lined up with the edge of the outermost indentation on the sample holder).

2) Place a very small amount of your sample on a piece of weighing paper or a watch glass.

3) Peel a coated abrasive pad off of the sheet, and gently rub it over your sample. Alternately, you can put a small amount of your sample onto a spatula and smear it onto the pad. Do not load too much sample onto the pad! More often than not, you will not be able to remove sample once it is on the pad. Less is more! Typically, you should not be able to see your sample on the pad. If you find that the intensity of your spectrum is low, you can always add more sample later.

4) Stick the pad with your sample onto the holder, lining it up with the edge of the other (innermost) indentation.

5) Slide the sample holder into the accessory as far the first click. Collect a background spectrum of the reference pad. See "Instructions for Using the Spectrum RX-1 FT-IR" for further information.

6) Push the sample holder into the accessory as far as the second click. Monitor the energy reaching the detector. See above (Monitoring the Energy of the RX-1 FTIR Instrument) for instructions. The energy value should be roughly 90% of what you saw when you checked the operation of the accessory above. Note: If the energy is significantly lower, it means you have too much sample on the pad. You can try to remove some of the sample with a KimWipe or spatula, but most of the time you will need to prepare and analyze your sample again.

7) If necessary, slowly turn the focus knob on the front of the accessory clockwise or counterclockwise to maximize the energy throughput.

8) Hit the red Cancel button until you reach the main screen. The instrument will beep angrily at you.

9) Collect a spectrum of your sample. See "Instructions for Using the Spectrum RX-1 FT-IR" for further information.

Collecting Spectra Using Abrasive Sticks

1) Before you collect spectra using the abrasive sticks, check the operation of the accessory using an abrasive pad. See above (Checking the Operation of the Accessory) for instructions.

2) Hold the sample holder in your right hand with your thumb near the end with the slight indentations. (Your thumb will not be in the large groove on the side of the holder). Make sure the holes for the sticks are facing up and away from you. The hole furthest from you is for the reference stick. Place a coated abrasive stick into this hole with the coated (textured) end facing up.

3) Place a very small amount of your sample on a piece of weighing paper or a watch glass.

4) Gently rub the coated (textured) end of another stick over your sample. Alternately, you can put a small amount of your sample onto a spatula and smear it onto the stick. Do not load too much sample onto the stick! More often than not, you will not be able to remove sample once it is on the stick. Less is more! Typically, you should not be able to see your sample on the stick. If you find that the intensity of your spectrum is low, you can always add more sample later.

5) Place the stick with your sample into the other hole (closest to you) near the reference stick.

6) Slide the sample holder into the accessory as far the first click. Monitor the energy reaching the detector. See above (Monitoring the Energy of the RX-1 FTIR Instrument) for instructions. The energy value should be similar to what you saw when you checked the operation of the accessory above.

7) If necessary, slowly turn the focus knob on the front of the accessory clockwise or counterclockwise to maximize the energy throughput.

8) Hit the red Cancel button until you reach the main screen. The instrument will beep angrily at you.

9) Collect a background spectrum of the reference stick. See "Instructions for Using the Spectrum RX-1 FT-IR" for further information.

10) Push the sample holder into the accessory as far as the second click. Monitor the energy reaching the detector. See above (Monitoring the Energy of the RX-1 FTIR Instrument) for instructions. The energy value should be roughly 90% of what you saw when you checked the operation of the accessory above. Note: If the energy is significantly lower, it means you have too much sample on the stick. You can try to remove some of the sample with a KimWipe or spatula, but most of the time you will need to prepare and analyze your sample again.

11) If necessary, slowly turn the focus knob on the front of the accessory clockwise or counterclockwise to maximize the energy throughput.

12) Hit the red Cancel button until you reach the main screen. The instrument will beep angrily at you.

13) Collect a spectrum of your sample. See "Instructions for Using the Spectrum RX-1 FT-IR" for further information.

14) When you are finished, remove the stick with your sample by placing your thumb in the groove on the side of the sample holder and pushing the stick upwards.

Collecting Spectra Using Pans

1) Before you collect spectra using the pans, check the operation of the accessory using an abrasive pad. See above (Checking the Operation of the Accessory) for instructions.

2) Place a small amount of KBr of KCl into a mortar. Grind up the powder with a pestle. The finer the particles, the better. Note: Dry the KBr or KCl in the oven before use to avoid seeing a water peak in your spectrum.

3) Add some KBr or KCl powder to a pan using the small funnel.

4) Tap the pan on the bench or use a spatula to level the powder.

5) Hold the sample holder in your right hand so that your fingers are in the large groove and the deep wells are facing up. The outermost well on the sample holder (furthest away from you) is for the pure KBr or KCl. Place the pan containing KBr or KCl into this well.

6) Place a very small amount of your sample into the same mortar. Add KBr or KCl powder until there is about 5% sample. Grind up the powder and the sample using a pestle. Once again, the finer the particles, the better.

7) Add some of the mixture to a second pan using the small funnel.

8) Tap the pan on the bench or use a spatula to level the powder.

9) Place the pan containing your sample into the innermost well (closest to you).

10) Slide the sample holder into the accessory as far the first click. Monitor the energy reaching the detector. See above (Monitoring the Energy of the RX-1 FTIR Instrument) for instructions. The energy value should be similar to what you saw when you checked the operation of the accessory above.

11) If necessary, slowly turn the focus knob on the front of the accessory clockwise or counterclockwise to maximize the energy throughput.

12) Hit the red Cancel button until you reach the main screen. The instrument will beep angrily at you.

13) Collect a background spectrum of the KBr or KCl. See "Instructions for Using the Spectrum RX-1 FT-IR" for further information.

14) Push the sample holder into the accessory as far as the second click. Monitor the energy reaching the detector. See above (Monitoring the Energy of the RX-1 FTIR Instrument) for instructions. The energy value should be roughly 90% of what you saw when you checked the operation of the accessory above. Note: If the energy is significantly lower, it means you have too much sample in the pan. Try adding more KBr or KCl to the mixture in the mortar. This will "dilute" your sample. Make sure to grind the mixture again with the pestle.

15) If necessary, slowly turn the focus knob on the front of the accessory clockwise or counterclockwise to maximize the energy throughput.

16) Hit the red Cancel button until you reach the main screen. The instrument will beep angrily at you.

17) Collect a spectrum of your sample. See "Instructions for Using the Spectrum RX-1 FT-IR" for further information.

18) When you are finished, remove the pans from the sample holder and empty the material into a waste container. Rinse the pans with water to remove any remaining residue and allow them to dry.