Arsenic Mass Concentration in Urine (24-hour collection)

Why This Test Is Done

Your healthcare provider may order this test if you have symptoms of arsenic poisoning, such as nausea, vomiting, or skin changes, or if you’ve been exposed to arsenic through work, contaminated water, or certain foods. It’s also used in monitoring people with known arsenic exposure, like those living in areas with naturally high arsenic in water.

What to Expect Before the Test

You’ll collect all urine for a full 24 hours, typically starting after midnight and ending the next midnight. Drink plenty of water to help flush out arsenic naturally. Avoid certain foods or supplements that might contain arsenic (e.g., some seafood or supplements) unless instructed otherwise.

What to Expect During the Test

You’ll provide a single urine sample at the end of the 24-hour period. The sample is sent to a lab for analysis using a high-performance liquid chromatography (HPLC) method to measure arsenic levels precisely.

What the Results Mean

Results are compared to reference ranges for arsenic in urine, which can vary by age, sex, and other factors. High levels may signal recent or chronic exposure, while normal levels suggest no significant exposure. Your provider will discuss results in the context of your health history and symptoms.