Instructions for using Go!Link Data Acquisition with the Pharmacia UV-1

Transcription

1 Instructions for using Go!Link Data Acquisition with the Pharmacia UV-1 Introduction The Go!Link interface, the Instrumentation Amplifier, and the Logger Lite software permit data acquisition from just about any signal source. This guide explains how to use them to acquire data from the Pharmacia UV-1 unit. Typically, this is a chromatogram from some sort of preparative chromatography. Refer to the UV- 1 manual for more detailed instructions on using this detector unit. Wiring Diagram Set Up 1. Be sure that all connections are made as shown in the wiring diagram. 2. Turn on the power on the UV-1 control unit. Let the unit warm up for at least one hour. 3. On the Control Unit UV-1, set the switch on the left side to Range AU. 4. Set the knob on the Instrumentation Amplifier to the ±20mV range. 5. If you are working in the cold room, allow the computer to cool for at least one hour before turning it on. 6. Start the Logger Lite software. 7. From the Experiment pull-down, choose Setup Sensors Go! Link 1. 1

2 8. Left click on the white box in the Go! Link: 1 dialog box and choose Instrumentation Amplifier. 9. You will now see Instrumentation Amplifier displayed in the upper right corner of the Go! Link:1 dialog box. Left click on this and select the INSTR Amp +/-20mV <Computer> calibration for the Instrumentation Amplifier. This calibrates the amplifier for the ±20 mv range. 10. Close the Go! Link: 1 dialog box. 11. Turn the range knob on the Control Unit UV-1 to SHORT. This sets the UV-1 output voltage to zero. Zero the amplifier by pressing CTRL and 0 on the computer or from the Experiment pull down menu. 12. Set the range knob on the Control Unit UV-1 to a setting appropriate for your application. 2

3 Configuring Data Acquisition 1. Choose Data Collection from the Experiment pull down menu. 2. Set up a time-based data acquisition. Choose a length appropriate to your method. (A run can be stopped early if you wish, but it can not be extended past the length you choose here.) Use 10 samples per second if you want to use the fraction marker (see below). If you do not need the fraction marker, 1 sample per second should be adequate for most preparative chromatography applications. 3. Click done when you are finished setting up the acquisition, click on Done. 4. In the lower left corner of the Logger Lite window, you will see a digital voltmeter. Start the flow of mobile phase thru your chromatography system and thru the flow cell of the Optical Unit UV-1. You can watch the 3

4 signal from the detector by observing the potential. Use the Zero knob on the Control Unit UV-1 to bring the potential close to zero. (If you need to turn the knob to the extreme clockwise or counter clockwise positions, there may be a problem.) Wait for the potential to stabilize to ~ ±0.2 mv. 5. If you are going to use the fraction marker (see below) set the potential to about +0.5 mv using the Zero knob after it has stabilized. If you do not need the fraction marker, set the potential to 0 mv instead. These values correspond to the zero absorbance baseline. Acquiring Data 1. Start data collection by pressing F11, choosing Start Collection from the Experiment pull down menu, or pressing the big green Collect button on the toolbar. 2. To mark your fractions on the chromatogram, briefly press the fraction marker button. Pressing the button sets the potential to 0.00 mv for as long as you hold the button down. The fraction marks will appear as negative spikes in your chromatogram. If you hold the button too long, your spike will appear as a valley. If you press it too briefly, the spike might not reach to the baseline. 3. Data collection will stop when the time limit you set is reached. You can also halt your run by pressing F11, choosing Stop Collection from the Experiment pull down menu, or by pressing the red stop button on the toolbar. 4

5 4. When you are done with your run, save your data from the File pull down menu. Since the current data acquisition computer can not access the network from the cold room, it is recommended that you save your data onto a USB flash drive, transfer it to your own computer and print it from your own computer. (You will need to have Logger Lite installed on your computer.) 5. After saving your data, clear it from Logger Lite by choosing Clear All Data from the Data pull down menu. (It is possible to display and store multiple runs in a single file if you wish. Consult the Logger Lite online help for more details.) 6. You can print your chromatograms directly from Logger Lite. Choose Print Graph from the File pull down menu. Data can also be copied and pasted into Excel or other applications as needed. Useful Tips Although the UV-1 output is supposed to be 0-10 mv, it will produce signals outside if this range if it is off scale, particularly if the absorbance is too high for the absorbance range chosen. For example if the peak has an absorbance of ~0.5 and the range is set to 0.02, the peak will be off scale. On the ±20 mv scale, the Instrumentation amplifier will max out at ±25.21 mv. 5