Measuring volumes

The instructions below show the process for drawing up a volume of liquid to be added to a reaction without any requirements of inert atmospheres. These would be reagents where there is no septum in place on the top of the bottle. If a septum is present, follow the instructions for syringing under a modified atmosphere.

In many ways the syringing under a modified atmosphere is an easier technique to learn before adapting to draw up liquids not under an inert atmosphere. You may wish to start with that guidance, before reading the guide below.

1. Select an appropriate needle and syringe for use. Considerations may include:

• Amount of liquid to be dispensed and the syringe volume

• Length of needle required (generally long needles are used)

2. You may wish to clamp the reagent bottle to ensure that it is securely held in place during the syringing

3. Remove from the paper packaging and attach the syringe and needle together 

4. Insert the needle into the reagent bottle below the level of the liquid

5. Holiding on to the syringe barrel, pull up the plunger which will cause the liquid to begin being pulled into the syringe

• Note that the viscosity of the liquid will exert resistance for drawing up the solution, you may need to be patient for the material to be fully drawn into the barrel

6. Draw up the liquid to beyond the mark for the amount you require

7. Hold onto the needle where it joins the syringe barrel

• Whenever expelling content from a syringe, it is crucial to have control of this joint. As liquid is expelled, the pressure can force the joint apart which would cause the liquid to spray. Depending on the hazards of the material, this can be hazardous.

8. With the syringe and needle held between your thumb and finger, and with the needle in the bottle, carefully bend the syringe over, so that the syringe is inverted with the bottle remaining upright

• If the bottle is not secured by a clamp, you will also need to hold this in place.

• With smaller bottles, it is possible to acheive the holding of the bottle and syringe/needle joint in place with one hand, and use the other hand to control the expulsion from the syringe.

9. Allow any any air bubbles to rise to the needle exit from the syringe

• Air bubbles should rise to the top of the inverted syringe, but in very visous liquids, this may need to be encouraged by tapping the syringe.

• Depending on the syringe design, the 'Luer lock' which connects to the needle may be central, or it may be to one side of the barrel. If it is to one side, you may need to carefully rotate the syringe in the needle (without detaching), so that the Luer lock is uppermost, with the air bubbles collecting at this point.

10. Expel these air bubbles, ensuring the needle is securely held in place onto the syringe and that the needle remains inside the reagent bottle

11. Continue to expel from the syringe pushing the liquid out until you reach the required volume on the syringe

• Ensure the needle remains held in place onto the syringe.

• Ensure that the needle remains inside the bottle.

12. Take hold of the syringe barrel, and needle/syringe joint in one hand, and control the needle with the other as you remove the needle from the bottle

13. Transfer the needle inside the flask to which the contents need to be added

14. Ensuring the needle/syringe joint is held securely, expel the syringe contents into the flask

• Pay attention to any reaction requirements, for example slow addition.