📚 Edexcel A-Level Chemistry: Combined Analytical Techniques | 爱德思 A-Level 化学：综合分析技术
Organic structure determination in Edexcel A-Level Chemistry, particularly in Modern Analytical Techniques II, often requires you to combine mass spectrometry, infrared spectroscopy and NMR data. This article gives you a reliable strategy, key data ranges and common exam pitfalls so you can deduce structures with confidence.
在爱德思 A-Level 化学“现代分析技术 II”中，确定有机结构通常需要综合质谱、红外光谱和核磁共振波谱数据。本文提供可靠的解题策略、关键数据范围和常见考试陷阱，帮助你自信地推断有机物结构。
1. Overview of Combined Analytical Techniques | 综合分析技术总览
Combined analytical techniques use complementary evidence. Mass spectrometry gives the relative molecular mass and fragmentation patterns, infrared spectroscopy identifies functional groups, ¹H NMR reveals hydrogen environments and ¹³C NMR counts non-equivalent carbon environments. When used together, these techniques can determine the full structure of an unknown organic compound.
综合分析技术利用互补的证据。质谱提供相对分子质量和碎片模式，红外光谱鉴别官能团，¹H NMR 显示氢环境，¹³C NMR 统计非等效碳环境。综合使用这些技术可以确定未知有机化合物的完整结构。
| Technique | Information obtained | Typical unit |
|---|---|---|
| Mass spectrometry | M⁺ peak gives Mᵣ; fragments give structural clues | m/z |
| Infrared spectroscopy | Functional group identification | cm⁻¹ |
| ¹H NMR | Number, environment and ratio of hydrogen atoms | δ / ppm |
| ¹³C NMR | Number of non-equivalent carbon environments | δ / ppm |
In exam questions, you will normally be given just enough data from all four techniques. Your job is to use each piece of evidence in a logical order rather than guessing from a single spectrum.
在考试题目中，你通常会得到来自这四种技术的足够数据。你的任务是按逻辑顺序使用每一条证据，而不是仅凭单一谱图猜测。
2. Mass Spectrometry: Finding the Molecular Formula | 质谱：确定分子式
The highest m/z peak in a simple molecular ion region is usually the molecular ion peak, written as M⁺. The m/z value of M⁺ gives the relative molecular mass Mᵣ. In Edexcel A-Level questions, you often combine this with percentage composition
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