If the odor of sulfur is still present why does a sulfide test indicate there is no sulfide in the sample?

Document ID

Document ID TE1194

Published Date

Published Date 27/05/2017
Question
If the odor of sulfur is still present why does a sulfide test indicate there is no sulfide in the sample?
Summary
Sulfide odor is present but test results indicate no sulfide
Answer
The threshold odor concentration of hydrogen sulfide in clean water is between 0.025 and 0.25 ppb (per Standard Methods), thus the hydrogen sulfide odor may be present even though test results indicate a concentration of zero.