Solid-Phase Extraction Is a Sample Preparation Technique

question 20

Multiple Choice

Solid-phase extraction is a sample preparation technique.Which of the following statements is(are) NOT true for an aqueous solid-phase extraction?
I Solid-phase extraction separates analyte from the sample matrix using a chromatography stationary phase.
II An aliquot of the aqueous sample is applied to the solid-phase extraction tube,washing the sample with additional sample and then a water wash.
III The analyte sticks to the column and the water wash removes all species that do not adhere to the column.
IV An organic solvent is used to wash the analyte from the column.
V The organic phase containing the analyte is evaporated to dryness and the solid is dissolved in water,ready for analysis.

• A)III
• B)I
• C)II and III
• D)IV
• E)II

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Definitions:

Unemployment Types

Categories that differentiate the reasons individuals are without employment, including cyclical, frictional, and structural unemployment.

Frictionally Unemployed

Individuals temporarily out of work while transitioning between jobs, often reflecting the natural movement in the labor market.

Recessionary Period

A time characterized by a significant decline in economic activity across the economy, lasting more than a few months.

Voluntarily Switching Jobs

The act of an employee choosing to leave one job for another, often for better pay, benefits, or working conditions.