USER MANUAL FOR THE iMETOS MobiLab NITRATE AND AMMONIA ANALYTICS
Table of Contents
First, download the Software here (bottom of the page).
Connecting the Device
First connect all the electronic devices to each other by USB cables included in the product. Link the USB hub to i) your computer, ii) to the shaker, iii) to the weighing scale and iv) to the iMETOS MobiLab. Then plug the hub to the wall adaptor or car battery.
You will be able to verify the connection of you device via the iMETOS MobiLab Software on your Windows computer.
If no chip is present insert a chip into your device first. First check if there is run buffer in the container. Open the container, then turn the Lab-on-a-chip device on its head and open the 4 screws of the chip clamp. You will find either wing nuts or hexagon screws on your iMetos Lab-on-a-Chip. In either case, you have to open the screws, take care not to lose the springs and then insert the chip like shown in the picture. The recesses of the chip fit exactly into the mold inside the chip clamp. Close the device again by using the 4 screws. Screw them tightly but do not apply force.
Every day when opening the Software for the first time, a guided setup is initiated. Complete the 4 Steps in the Device Setup.
- Scale Calibration
- Solution Preparation
- Set Method Version
- Device Rinsing
- Place an empty tube on the scale and click Step 1.
- Take the tube out and insert the calibration weight.
- Put the tube gently back on the scale and click Step 2.
- The Scale Calibration is done now.
To prepare Solution A, click on ‘Prepare’. If there is still Solution A left, click on ‘Already have’ and omit this step.
You can choose between two Set Method Versions:
Choose if you want to use:
- Solution B and Sedimatation
Check if you have Solution B in your set
Choose if you want to use:
- Distilled water and Filtration
Check if you have filterpaper in your set
Please check if there is a droplet formation on the bottom of the blue container. If so your chip conducts the liquid nicely and everything is fine.
Now you can do a test measurement.
This is how a perfect Baseline looks like.
Now your device is ready for measurement. In the next chapter, we will learn how to prepare the samples.
Sample preparation consists of five steps:
- Add sieved soil
- Add distilled water
- Shake the sample
- Filtrate the sample
- Transfer the sample
Sieve your soil through a 2 – 3 mm mesh sieve. Remove stones, plant parts or animals and mix the sieved soil well.
1. Open the Sample control tab
2. Click Add sample
After creating and labeling your sample (here it’s 123) it will be shown in a row in the Sample table.
Simply follow the buttons which appear in the row one by one. First, determine the weight of your sieved soil sample. For this, put an empty tube in the scale and click ‘SET WEIGHT’. (If the empty tube is not ~0g, click ‘Tare’)
Fill the tube with 10 g sieved (and well mixed) soil and click ‘SAVE’. There is a tolerance of 10 %, meaning anything from 9 g to 11 g will be accepted.
A new button appears. Simply leave the tube on the scale and click ‘SET WEIGHT’ for adding the water. Add 20 g of distilled water (equals 20 ml) to your soil, with the squeezing flask. Also here a tolerance of 10 % applies. This means adding anything from 18 to 22 ml will be accepted.
1. Remove the tube from the scale, cap it, write the sample ID on it and put it into the shaker. Now start the Shaker timer.
2. After 25 minutes, your sample is well mixed. Stop the shaker by using the shaker symbol on the left side of the software and place the tube into the rack. Continue the shaker by clicking on the same symbol if you have more samples on it.
1. Place a new tube next to the one you just prepared in the rack and put a funnel on top of it.
2. Take a filter paper, place it in the funnel and fill the whole sample into the funnel. This should result in a more or less clear liquid.
3. Now you can click on the filtration symbol.
Take a 2 ml vial with a paper inside and add 1 ml (this is 1000 µl) of the liquid you just filtrated. Use the 1000 µl pipette with a fresh blue tip. Close the vial, shake it for some seconds by hand. Your sample is now ready for measurement.
After finishing the filtration, a ‘Add new’ button appears.
Click on it, choose which measurement device you want to use and start the measurement.
Take a fresh yellow tip with the 50 µl pipette and take up your finished sample from the small vial.
Add it into the small hole of the Lab-on-a-Chip device, during a 10 seconds time window announced by the software.
The measurement is now running. You see now a graph in a window on the bottom right in the software. The graph will be maximized if you click on this window. Wait until ‘finished’ pops up and then remove your sample with the pipette.
Note: For leaving your device for more than 1 hour unattended, fill distilled water inside the sample hole, this will protect your chip.
If you choose a Nitrate AND Ammonium measurement, you need to take up the sample in the pipette after the nitrate measurement concludes. Add it again as soon as the ammonia measurement starts. For this you will be offered another 10 seconds countdown for insertion.
Rinse the sample hole 2 times with distilled water before measuring the next sample for the best result. A maximum of 100µl sample volume is required.
MobiLab loves to be cleaned!
When you finished the use of MobiLab for your day, remove the Solution A (Runbuffer) from the containers by using the syringe. Also remove the sample with the pipette. Fill both containers with 1 or 2 ml of distilled water, close them and click on the pump symbol on the left side of the software. Switch the pump on for around 2 or 3 min. The chip is now being rinsed. Take a fresh pipette tip and fill the sample hole with distilled water. Now click again on the pump icon again to stop it.
If you are to put the MobiLab for a longer rest (more than 2 days) remove the water from every container and sample hole and store the device.
- The solution levels in the device are very important for your results! (Left 4ml/Right 5ml of Runbuffer/Solution A).
They will change after every measurement. AFTER EVERY 10th measurement, you should transfer (~200µL/ first line from 5ml syringe) solution from the right container – to the left container!!
The levels of the solution should look like this. (see picture)
- After every measured sample, rinse the sample hole with the following sample (or distilled water) to improve your results.
- The Sample hole should not run dry (i.e. no sample or water) for more than 15 minutes.
- When you want to change the chip, ALWAYS remove all liquids from the device first! Clean the old chip with distilled water (see cleaning) , remove the water and then put in the new chip. A new Inizialisation is needed then.
- To get a good measurement keep your system always AIRBUBBLE-FREE:
These 2 holes are connecting the chip directly. Remove airbubbles with the syringe!
- Do not spill any liquid on the chip clamp. Liquids are to be put just into the containers and the sample hole.
- After cleaning leave the chip inside the device. The chip ages with every time you insert or remove it.
- Soil samples have to be measured as soon as possible after preparation. Try not to exceed 15 minutes.
- Store your prepared Solution A in the fridge (lifetime 1-2 weeks) or in the freezer (lifetime up to one year) to avoid biologic degradation. The duration at room temperature is roughly 3 days.
- And finally, once per usage month you should apply silicone grease on the 3 O-rings inside of the chip clamp. This helps to avoid a leakage. (see Help/FAQ in the software)
If you have problems with a section above please contact our Pessl Instruments support service.