Difficulty: Easy
Correct Answer: Solids and metal analysis (elemental identification/trace levels)
Explanation:
Introduction / Context:
Emission spectroscopy (including arc/spark OES, ICP-OES) measures the light emitted by excited atoms or ions to determine elemental composition. It is a cornerstone technique for metallurgy, quality control, and trace analysis in solids and solutions.
Given Data / Assumptions:
Concept / Approach:
Each element emits light at characteristic wavelengths when excited. By dispersing the emitted light and measuring intensities, one can identify and quantify elements at ppm to sub-ppm levels. Arc/spark sources are common for bulk metals; ICP-OES excels for multi-element analysis in solutions. These strengths make emission spectroscopy ideal for solids and metals analysis.
Step-by-Step Solution:
Identify the measurement principle: emission of characteristic lines.Match typical industrial tasks: alloy grading, impurity profiling, certification.Select “solids and metal analysis.”
Verification / Alternative check:
Standards for steel, aluminum, and other alloys routinely specify spark OES or ICP-OES methods, highlighting this technique’s dominance in metals labs.
Why Other Options Are Wrong:
Water purity: Conductivity/TOC/UV254 methods are typical, not emission spectroscopy alone.CO2 gases: Non-dispersive infrared (NDIR) is the norm.NOx: Chemiluminescence or UV methods dominate.Turbidity: Nephelometry is used, not emission OES.
Common Pitfalls:
Confusing emission with absorption techniques (AAS) or with molecular spectroscopies (IR/UV-vis) that target different analytes and matrices.
Final Answer:
Solids and metal analysis (elemental identification/trace levels)
Discussion & Comments