Principles of Analytical Techniques (SBT 409)

These flashcards cover essential concepts from the lecture on analytical techniques. They focus on definitions, processes, and criteria necessary for understanding the analytical methods discussed.

What is analysis in the context of analytical chemistry?

Analysis is the process of identifying, separating, and quantifying the components of a sample to understand its nature and composition.

What are the general steps in the analytical process?

1. Definition Of Analytical Problem 2. Selecting The Analytical Method 3. Sampling 4. Sample Preparation 5. Perform Measurement 6. Calculate Results And Report

Why is sampling considered a critical step in analysis?

Improperly selected samples can lead to large errors in accuracy and contribute more to overall precision than the instrument used.

What is the difference between specificity and selectivity in analytical methods?

Specificity refers to a method's ability to respond to one single analyte, while selectivity refers to the method's ability to respond to several different analytes.

What is the ultimate goal of analysis?

To obtain accurate results, though this is not always achievable, especially with selective methods.

What is selective precipitation in analytical methods?

Selective precipitation is used to isolate one component of a mixture by adding a chemical that specifically reacts with the desired component to form a precipitate.

What are masking agents used for in analytical chemistry?

Masking agents complex potential interfering elements in a sample solution, converting them into a non-interfering form.

What is solvent extraction and how does it work?

Solvent extraction is a technique where two immiscible or partially miscible solvents are agitated together to preferentially migrate a dissolved chemical species to one of the phases.

What is the purpose of sample preparation in analytical procedures?

To convert a representative sample into a form suitable for analysis while minimizing interferences and ensuring analytes are in detectable levels.

List some objectives of sample preparation techniques.

1. Conversion into a suitable form for analysis 2. Elimination of interfering species 3. Pre-concentration of trace analytes.

What are some challenges in preparing solid samples for instrumental analysis?

Majority of instrumental techniques require samples in a liquid phase; thus, techniques like dissolution, extraction, or decomposition must be used.

What factors influence the choice of an analytical method?

Factors include accuracy, detection limit, speed, legality, ease and convenience, skill required, and costs.

What are the reliability criteria for selecting a method?

Specificity, accuracy, precision, and sensitivity.

What should be balanced when selecting an analytical method?

One must balance various design criteria, ensuring the method provides the most accurate results while considering urgency and other factors.