Exam 1: The Analytical Process

A(n)____________________ sample is a sample where the chemical composition differs from place to place.

A(n)________________________________________is used to grind solids into smaller particles.

When extracting a sample with a liquid,the liquid is____________________ from the sample.

____________________ is the substance being measured during a chemical analysis.

A calibration curve for the determination of aspirin is constructed from known concentration aspirin solutions,mg/mL,and the HPLC peak area's for each standard.If the equation is y = 12.565x − 0.71,what is the concentration for an unknown that has a peak area of 83.5?

For separations,the plot of detector response versus time is a(n)____________________ and the area under the peak is____________________ to the quantity of compound passing through the detector.

____________________ occurs when a species other than analyte increases or decreases the analytical signal and makes it appear that the concentration is greater or less than the real concentration.

____________________ is the series of procedures applied to a sample prior to analysis.

____________________ chemical analysis is the measurement of how much of a chemical substance is present.____________________ chemical analysis is the determination of what is present in a sample.

A(n)____________________ is a suspension of a solid in a liquid.

____________________ is any chemical of interest.

Which statement is NOT true?

Which is NOT a general step in the analytical process?

________________________________________are repeated measurements to assess the variability in the analysis and to guard against a gross error in the analysis of a single aliquot.

A(n)________________________________________is a plot of detector response as a function of analyte concentration.The curve is constructed using________________________________________containing known concentrations of the analyte of interest.

____________________ is the process of procuring a representative sample to analyze.

The liquid above the packed solid following a centrifugation is the____________________ .

____________________ is the transformation of an interfering species into a form that is not detected.

A sample with a uniform chemical composition is a________________________________________sample.

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.