"residual levels" is correct and usable in written English.
You can use it to refer to the amount of something that is still remaining after a period of time or after something has been done. For example, "The factory was able to reduce its residual levels of waste by 30%."
Many (50%) of the samples contained pesticides, and three samples had residual levels above the maximum residue levels determined by the World Health Organisation.
Albendazole exhibited the highest residual levels in eggs while tiamulin recording the lowest level.
Similarly, the highest recorded value of tiamulin were found in the kidney while the liver showed a 4-fold decrease in residual levels.
Defect density dropped to residual levels after 1 min annealing at 300 ℃ and 400 ℃, while the material was still resistive with RSH above 108 Ω/□.
The more competitively aggressive clones could optimize their productivity when planted in sites with high residual levels, reaching productivities similar to those of homogeneous stands.
Chamotte clay was also able to remove residual levels of monoacylglycerols and diacylglycerols and provided samples with properties that are similar to those attained by traditional wet washing.
There were low residual levels of integration by NIL vectors (reduced approximately 104-fold compared to wild-type vectors), despite any combination of the engineered changes.
The agreement between SPMM and DNS is better than that between IECM and DNS, in terms of conditional diffusion iso-contour similarities and global normalized residual levels.
Such processes can explain these observations, but more investigation is needed to evaluate whether residual levels of CD can facilitate the anaerobic degradation of chlorinated VOCs.
Seven days after reperfusion, both groups displayed comparable residual levels of damages (figure 2).
The purified mutants contained the residual levels of the 10 kDa prodomain.
