Practical Inductively Coupled Plasma Spectrometry

John R. Dean

• Publisher: Wiley
• Year: 2019
• ISBN:
  9781119478744
• Edition: 2
• Topic: Scienze fisiche
• Subtopic: Spettroscopia e analisi dello spettro

A new edition of this practical approach to sampling, experimentation, and applications in the field of inductively coupled plasma spectrometry

The second edition of Practical Inductively Coupled Plasma Spectrometry discusses many of the significant developments in the field which have expanded inductively coupled plasma (ICP) spectrometry from a useful optical emission spectroscopic technique for trace element analysis into a source for both atomic emission spectrometry and mass spectrometry, capable of detecting elements at sub-ppb (ng mL ?1 ) levels with good accuracy and precision.

Comprising nine chapters, this new edition has been fully revised and up-dated in each chapter. It contains information on everything you need to practically know about the different types of instrumentation as well as pre- and post-experimental aspects. Designed to be easily accessible, with a 'start-to-finish' approach, each chapter outlines the key practical aspects of a specific aspect of the topic. The author, a noted expert in the field, details specific applications of the techniquespresented, including uses in environmental, food and industrial analysis. This edition:

• Emphasizes the importance of health and safety;
• Provides advanced information on sample preparation techniques;
• Presents an updated chapter on inductively coupled plasma mass spectrometry;
• Features a new chapter on current and future development in ICP technology and one on practical trouble shooting and routine maintenance.

Practical Inductively Coupled Plasma Spectrometry offers a practical guide that can be used for undergraduate and graduate students in the broad discipline of analytical chemistry, which includes biomedical science, environmental science, food science and forensic science, in both distance and open learning situations. It also provides an excellent reference for those in postgraduate training in these fields.

1
The Analytical Approach

LEARNING OBJECTIVES

• • To be aware of the different types of contamination that can cause problems in trace elemental analysis.
• • To know about Health and Safety in the working environment.
• • To be able to carry out a Risk Assessment for safe laboratory and in‐field practice.
• • To appreciate the units used in analytical chemistry.
• • To be able to report numerical data with the appropriate assignment of significant figures.
• • To be able to present numerical data with correct units and be able to interchange the units as required.
• • To know how to present and report laboratory information in an appropriate format.
• • To be able to determine the concentration of an element from a straight‐line graph using the equation y = mx + c.
• • To be able to calculate the dilution factor for a liquid sample and a solid sample, and hence determine the concentration of the element in the original sample.
• • To appreciate the concept of quality assurance in the analytical laboratory.
• • To be aware of the significance of certified reference materials in elemental analysis.
• • To develop an understanding of reporting and interpreting the data generated in its appropriate context.

1.1 Introduction

Trace elemental analysis requires more than just knowledge of the analytical technique to be used; in this case, inductively coupled plasma spectrometry. It requires knowledge of a whole range of disciplines that need to come together to create the result. The disciplines required can be described as follows:

• • Health and Safety in the laboratory (and external environment);
• • sampling, sample storage and preservation and sample preparation methodologies appropriate to sample type;
• • analytical technique to be used;
• • data control, including calibration strategies and the use of certified reference materials (CRMs) for quality control and data assurance;
• • data management, including reporting of results and their interpretation, context and meaning.

While most of these are covered to some extent in this book, the reader should also consult other resources; for example, books, scientific journals and the web.

1.2 Essentials of Practical Work

The perspective that is required when faced with trace element analysis are the additional precautions required in terms of management of contamination, choice of reagents and acids and cleanliness of the workspace. For example, the grade of chemical used to prepare calibration standards is a major concern when working at (ultra) trace element analysis levels (sub‐μg ml⁻¹). Chemicals are available in a range of grades from ‘reagent grade’ or ‘technical grade’ through to ‘analytical reagent grade’, for example, ACS reagent, AristaR^®, >99% purity or PUROM™, Optigrade^®, picograde^® and ReagentPlus^®. For ‘analytical reagent grade’ materials, the manufacturer has characterized the identity and concentration of impurities by subjecting it to stringent chemical analysis. Therefore, the use of sample and reagent blanks in the analytical procedure is essential to identify ‘problem elements’ that could interfere and to analyse and report data accordingly.

The risk of contamination is a major problem in trace element analysis. Apart from the analytical reagent used to prepare standards, as discussed previously, conta...