Inorganic Arsenic/Creatinine Ratio, 24-Hour Urine
Measures inorganic arsenic relative to creatinine in a 24-hour urine collection to help assess arsenic exposure.
["This test can help identify elevated arsenic exposure, but diet and supplements can affect the results."]
Key facts at a glance
- LOINC
- 52940-4
- Short code
- Inorg Arsenic/Creat 24h Ur-sRto
- Synonyms
- Inorg Arsenic/Creat 24h Ur-sRto
- Category
- kidney
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
What is this test?
This test measures inorganic arsenic in urine collected over 24 hours and compares it with the amount of creatinine in the same sample. Creatinine is used to help account for differences in urine concentration.
Why might I need this test?
It may be ordered to investigate suspected exposure to arsenic from occupational sources, contaminated water or soil, supplements, or other potential sources. Results can also be used to follow a person after an exposure or during occupational monitoring.
How is the test performed?
Urine is collected into a special container for a full 24-hour period. The laboratory then measures inorganic arsenic and creatinine and calculates their relationship. Your healthcare professional will interpret the result with your exposure history and other findings.
How do I prepare for the test?
Follow the laboratory's collection instructions carefully and record when the collection begins and ends. Some laboratories recommend avoiding seafood, seaweed, and arsenic-containing supplements for several days beforehand because they may affect results; do not stop prescribed medicines unless instructed.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
An elevated result may indicate increased exposure to inorganic arsenic, but it can also reflect recent dietary sources or laboratory and collection factors. The result should be interpreted alongside symptoms, work and water exposure, supplements, and repeat testing when appropriate.
Short name
24-Hour Urine Inorganic Arsenic
Frequently asked questions
Why is the result compared with creatinine?
Does eating seafood cause a high result?
How is a 24-hour urine collection completed?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy