1. 24-hour urine samples

2. Based on EHES Manual, Part B. Fieldwork procedures, 2nd edition, 2016
Available at:
These slides can be used freely, translated and adapted to national use (e.g. concerning the equipment). However, it is important to keep in mind that no changes should be made to the measurement techniques, which need to be standardized.

3. Exclusion criteria
24-hour urine sample is not collected from participants
with any condition that would make urine collection difficult
with menstruation
who refuse
Reasons for exclusion are recorded.

4. Pregnant participants
Results may need to be analyzed separately from those of other participants.
Pregnancy should be recorded.

5. 24-hour urine sample collection
Motivation of the participant
Explain to the participant that 24-hour collection is needed due to large diurnal variation.
The participant collects the sample at home.
The sample needs to be brought back to the examination site or picked up from the participant’s home.
The collection starts in the morning and ends the following morning.

6. Equipment for collection
Plastic beaker with lid for voiding, 1000 ml
Plastic collection container with lid, 3000 ml

7. Equipment for processing and storage
Pipet
Stirring rod, plastic
Freezer
Plastic storage tubes, e.g. 3 ml storage tubes
Cryo vials must be used if stored at -70°C or colder
Storage box for plastic tubes / cryo vials

8. Instructions to the participants (1)
Give the participant
A 1000 ml plastic beaker for voiding
A labelled 3000 ml plastic collection container with lid
written instructions on collection of 24-hour urine sample
sample collection recording form (also called laboratory form)
Encourage the participant to follow a normal day (eating and drinking) during the collection, but to avoid excessive physical activity and alcohol use.

9. Instructions to the participants (2)
Instruct the participant to start the collection in the morning by discarding the first void.
The date and time are recorded.
After this all urine is collected by using the beaker. From the beaker the urine is poured into the container.
The last void is collected when 24 (±2) hours have elapsed since the beginning of the collection.
End of collection (date and time) are recorded.

10. Instructions to the participants (3)
Storing of the sample:
During and after the collection, the container is stored in a cool place, preferably refrigerator (+4ᵒC), and sheltered from direct sunlight.
The urine must not be frozen (under 0°C) before processed by survey personnel.

11. Instructions to the participants (4)
Explain the delivery of the sample
Either deliver the sample to the examination site or laboratory, or agree on a schedule of picking the sample up from the participant’s home (according to the study protocol).
The sample should be delivered on the same day when the collection ends.

12. Sample delivery
Check the sample collection recording form with the participant.
Record the time and date, when the sample was delivered, in the sample collection recording form.

13. Processing of the sample
Mix the sample well and measure or read the volume. Record the measured volume in the sample collection recording form.
Transfer aliquots of 2 ml into storage tubes.
Label the tubes and store at -20 ᵒC or -70 ᵒC.
Preferably several aliquots are made for storage and future use.
The remaining urine is disposed of.

14. Incomplete samples Check the completeness of the sample.
The 24-hour urine sample is considered incomplete, if
the volume of the sample is ≤500 ml,
the collection time is <22 or >26 hours, or
“more than few drops” of urine were missed during the collection.
Reasons for judging a sample as incomplete should be recorded.

15. Acknowledgements Slides prepared by: Laura Paalanen
Photographs: Laura Paalanen
Experiences and feedback from the EHES network have been utilized in the preparation of these slides
Funding: Preparation of the slides is part of the activities of the EHES Coordinating Centre which has received funding from the EC/DG SANTÉ in through SANCO/2008/C2/02-SI EHES and Grand Agreement number , and in through Grand Agreement number /BRIDGE Health

16. Disclaimer
The views expressed here are those of the authors and they do not represent the Commission’s official position.