What is the term for a blank prepared from a clean sample and carried through the entire instrument workflow to assess instrument contamination?

• A. Method Blank
• B. Surrogate
• C. Instrument Blank
• D. Reagent Blank

Answer: (C)

Instrument blanks test instrument cleanliness by running a blank through the entire instrument workflow. They are prepared from a clean solvent or sample and then injected and processed just like a real sample, so any signal observed comes from the instrument itself—residual carryover, injector residues, column bleed, or detector noise. This makes them the best choice for identifying contamination that originates in the instrument, separate from contaminants introduced during sample prep or from reagents. Surrogates are used as recovery standards, reagent blanks check for contamination from solvents or reagents, and method blanks go through the full method including sample preparation. So the term that fits a blank carried through the full instrument process to assess instrument contamination is the instrument blank.