"certain samples" is a correct and usable phrase in written English.
You can use it when referring to a limited selection of items (such as a group of products or test results), to indicate that the selection is specific and limited. For example: "The researchers studied certain samples from the experiment to draw their conclusions."
It was possible to obtain remarkably high fractions of CSL boundaries in certain samples.
Subsequently, platinization of certain samples was carried out using a photodeposition method.
KCl was deposited onto certain samples to understand the mechanism of high temperature chlorine-induced corrosion.
For certain samples, the concentration of TSS in the outlet was higher than the TSS concentration at the basin inlet, suggesting sediment re-suspension.
That means that certain samples they tested are not treatable with existing vaccines, which target certain gene clusters that have now changed.
Certain species, for example, housed prokaryote communities similar to seawater (LMA sponges) while others (HMA sponges) housed communities similar to those found in certain samples of nudibranchs and sponge denizens.
The EPA management authority may require that certain samples be submitted on a routine basis to EPA laboratories for analysis as well as being analyzed by the surveyor, and that EPA personnel participate in some field surveys.
Analysis by thermal methods and powder x-ray diffraction (XRPD) revealed that certain samples contained a phase impurity, and that this could be "cured" during storage.
As described above, the dominant microbial populations in the deep-sea surface sediments, particularly the more heavily impacted samples, were markedly different from what was reported in the water column, except for Colwellia, which was abundant in certain samples in both environments.
Certain differences between cyclic voltammograms observed for gold faces (100) oriented under given experimental conditions, are shown to be due to the presence of defects beyond equilibrium concentration in certain samples.
Certain samples were also leached under saturated conditions.
