Best Practices for using Aryballe Devices – Tips and Tricks

NeOse Advance and its accessories are analytical equipments that must be used accurately and consistently to generate reliable results. 

Environmental conditions

• Ensure that you are working in a stable environment over the course of your experiment, in terms of both temperature and humidity (less than5% variation in humidity, 2°C in temperature).
• Avoid working in direct proximity of a ventilation, HVAC system, or any turbulent airflow.
• Avoid working in direct sunlight as it can affect the temperature stability of the equipment. 

• It is essential to work in a clean environment with minimal olfactive pollution. Ideal experimental conditions involve working with a clean, repeatable baseline or at a minimum with low olfactive pollution that remains the same across the experiment.

• If your environment has a strong odor background, be aware that it can impact the accuracy of your results. 

Preparing Samples

Liquid samples

• Vortex the sample just before transfer to the experimental vial. When working with several different samples, vortex each sample just before transferring it to a new vial. 
• We recommend using 0.25 mL of liquid per sample for testing to generate a stable and concentrated headspace in a 20 to 100 mL vial. Using a small quantity of sample prevents damaging the sensor in case of liquid aspiration.When using larger vials, the volume of samples can be adapted accordingly.
• Place a clean magnetic stirrer inside the vial to agitate the sample and generate a homogeneous headspace.
• When discarding used pipette tips, do not move over empty vials.This prevents potential contamination.

Solid samples – powder

• Do not agitate powder samples as it can cause dust pollution of the sensor.
• We recommend using about 1g of solid powder samples for a 60 mL vial. 

External Material and Equipment

Throughout the experiment, always wear gloves and ensure you do not cross-contaminate samples and equipment. 

Septum

When using new septa, ensure they have had enough time to degas as new materials have been found to emit distinct odors that can impact your tests: 

• For septa made of silicon or PTFE, place septa in an oven at 110°C for a minimum of 4 hours. 
• For septa made of butyl or other materials, please refer to the recommendations of your supplier. 
• If possible, check their signal using PID equipment: it should indicate a value close to 0. 

Pipettes

• Wipe the end of your pipette with a tissue appropriate chemical use to avoid cross-contamination of samples. After about a dozen samples, discard the tissue and use a clean, new one. 
• When not in use, store pipettes vertically. 
• We recommend using positive displacement pipettes, which are easier to use when working with viscous liquids and prevents contamination inside the pipet (liquid or gas). 

Magnetic StirringPlate

Some commercial stirring plates generate heat, which can affect the accuracy of the tests run.

• Ensure your stirring plate does not generate heat—the temperature at the surface of the stirring plate can be measured using a laser thermometer after 30 minutes of operation. 
• If heat is generated, ensure that the warm-up of this equipment is consistent and standardized across experiments for a stable temperature. 

Clean up of material

While we recommend working with single-use vials to minimize the pollution and cross-contamination risks, some materials (vial caps, septa, magnetic stirringbars) can be reused after a thorough cleaning procedure is carried out. 

Clean up Procedure

• 3 acetone rinsing: place used materials in a beaker and pour100% acetone on them. Swirl the beaker. Discard liquid and repeat this step 2more times. Do not bathe materials as acetone can dissolve some materials. 
• 3 ethanol rinsing: place used materials in a beaker and pour 95% ethanol on them. Swirl the beaker. Discard liquid and repeat this step2 more times. 
• 1 soap bath: Submerge material for a minimum of 4 hours, ideally overnight, in an unscented soap solution. We recommend using Frank lab’s TFD4detergent solution. 
• Water rinsing: rinse material under running water until you can no longer see bubbles.
• Distilled water rinsing: briefly rinse material with distilled water.
• Drying: place in an oven at 110° C for 4 to 6 hours if your materials allow it. If this is not the case, adjust the temperature to accommodate the nature of your material.  

Validation of the clean-up procedure

• For magnetic stirring bars: 
  • Place the bars inside of a clean, empty vial.
  • Measure signal using PID equipment Compare it with the signal obtained from an empty vial with no stirring bar in it. Both readings should be equal and close to zero.
  • If you do no thave access to a PID, start a measurement using the NeOse Advance and Aryballe Suite’s Live Data View. The signal intensity should remain under 0.2 radians. 

• For septa: 
  • Place the septa inside of a clean, empty beaker.
  • Measure signal using PID equipment: place the PID inlet in close proximity of the septa to be controlled. Ensure that no signal can be detected.
  • If you do not have access to a PID, start a measurement using the NeOse Advance and Aryballe Suite’s Live Data View. The signal intensity should remain under 0.2 radians.

Clean up of HeptaValve Mini

Make sure you are using the Pump Box provided with your HeptaValve Mini for cleaning up. Using the NeOse Advance for this step would affect the lifetime of the device pump and increase the risk of pollution of the sensor. 

Fluidic

• Make sure all the HeptaValve Mini tubing are the same length.
• When not in use, place transparent caps on inlets for Amplifier and NeOse Advance.
• If using an empty vial for the Baseline inlet of the HeptaValve Mini, open the vial after each run to renew the air.