Chapter 3 atomic emission spectroscopy

CChapter 3 hapter 3 Atomic Emission SpectroscopyAtomic Emission Spectroscopy

3.1. Fundamentals of AES

3.2. Instrumentation

3.3. Analytical Methods of AES

3.4. Control of Analytical Interferences

3.1. Fundamentals of AES

Atomic Emission Processes

3.2. Instrumentation

1. Light source 2. Spectrometer3. Detector 4. Readout

1. Light Source

Type Eva.Temp. Exci. Temp. stability Application.

DC Arc high low poor Qualitative Analysis

AC Arc mid mid good Qualitative Analysis

Spark low highest good Quantitative Analysis

ICP highest high best Quantitative Analysis

Light Source Progresses

2. Spectrometer

⑴Monochromater Optical-direct Read Spectrometor

⑵Polychromater Optical-direct Read Spectrometor

3. Detector

⑴Spectrograph

⑵Photomultiplier Tube

⑶Segmented-array Charge-Coupled

Detector(SCD)

4. ICP-AES Instrumentation System

Two-dimensional array produced by the echelle mount

Fig 3-16 Scheme of SCD Detector

3.3 Analytical Methods of AES

1. Qualitative Analysis

⑴Standard Iron Spectra Comparison

⑵Indicate Element Spectra Comparison

⑶Determination of Line Wavelength

2. Quantitative Analysis

Quantitative Formula

⑴theoretical Formula of AES

ne

gI i

kTuululul

E

x

x

ZhvA

u

11

1

neg

vhAI ikTul

ululul

E

x

x

Z

u

11

bi can

(3.1)

(3.2)

(3.3)

⑵Lomakin Formula

Internal Standard Methods⑶

Standard Calibration Methods⑷

bACI

bx

bxb

ss

x

s

x KCCCA

A

I

IR

KCbR lglglg

(3.4)

(3.5)

(3.6)

3.4. Analytical Interferences

1. Spectrum Interference

2. Background Interference

3. Matrix Interference

1. Spectrum Interference

2. Background Interference

3. Matrix Interference

3.5 Sensitivity and Detection Limit

1. Detection limit

ss

CR

LD3

.. (3.7)