Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
The inset shows an expanded view at low concentrations. The error bars represent standard deviations (n = 3). The “3σ line” was used for calculation of the LOD. This line was drawn at the position 3σ higher than the y-intercept of the fitting curve, where σ denotes the standard deviation of zero-concentration data (n = 5).
