Teledyne Leeman Labs Blog

In this edition of the blog, we will continue to examine various methods of sample preparation.

Dry Ashing

Samples containing a high percentage of organic matter (biologicals and foodstuffs, for example) can be prepared by a procedure known as "dry ashing" With this technique, an amount of sample is heated in a crucible over a flame or in a muffle furnace. The use of a muffle furnace is preferred as it permits greater control of the temperature. The sample residue is then dissolved, and the analysis is performed.

What Is ICP Heavy Metal Analysis?

Heavy metals, including arsenic (As), cadmium (Cd), chromium (Cr), lead (PB) and mercury (Hg) occur naturally in nature, and in low concentrations pose little health risk. When concentrations increase however, their presence can be toxic to plants, animals and humans. Because they are systemic toxins, routine testing is used to determine their presence and concentration. The United States Environmental Protection Agency (U.S. EPA), and the International Agency for Research on Cancer (IARC), classifies these metals as either “known” or “probable” human carcinogens.¹

This is part 2 of the Inductively Coupled Plasma Optical Emission Spectrometry series.  Part 1 described what ICP-OES is and how it works.  Part 2 will be an overview and cover some of the components.

Overview

Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) is a multi-element, trace-analysis technique used to measure the concentration of various elements in a variety of sample matrices. Also known as Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES), the technique is capable of measuring the majority of the elements in the Periodic Table and is currently one of the most widely used methods for elemental analysis today.

A majority of samples analyzed by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) are introduced to the instrument as solutions. Sample preparation for analysis by ICP-OES may be as simple as filtering and adding acid to a liquid sample or be a lengthy, complex procedure to dissolve a solid. In order to obtain the best possible analytical results, an appropriate technique must be used to convert the sample into a usable solution. Part 1 and 2 of this blog will briefly examine some of the more commonly used sample preparation techniques, and highlight their respective advantages and disadvantages.

For most applications, the ICP-OES requires the sample be in liquid form. Solid samples can be acid digested or dissolved in a solvent suitable for use with the ICP.

Liquid samples are delivered to the ICP using a sample introduction system, which is made up by the torch, spray chamber, nebulizer, peristaltic pump and tubing. In this blog post, we will look at the nebulizer.

Selecting the right ICP requires consideration of analytical requirements, available technologies, manufacturer specific features and benefits, estimation of current and future sample loads (as well as the number of
elements determined), warranty and service offerings, and instrument cost vs return on investment (including the cost of analysis). While it can be difficult to navigate industry terminology, the answer to what ICP fits your needs, is not difficult to determine.

The American Chemistry Society recently took a look at the chemistry of olive oil in a recent episode of its YouTube show, Reactions.

The debate about whether olive oil is healthy continues, but there is a lot of chemistry that goes on to produce a bottle.

With millions of consumers reportedly getting sick each year from foodborne diseases, how do food analysts know the best methods to keep products safe, manage risk and protect the integrity of their brands?  With the variety of methods available in the battle of food defense, food safety experts have to carefully hone their choices. A recent article in Lab Manager magazine went into more detail about a few of these methods.

When it comes to analytical testing, there is a single organization that sets the requirements and develops the methods for determining the purity of reagent chemicals, the American Chemical Society (ACS).

Teledyne Leeman Labs recently completed an analysis of reagent chemicals to determine their ultratrace elemental levels. The purpose of the analysis was to “demonstrate the ability of the Teledyne Leeman Lab’s Prodigy7 simultaneous ICP-OES, to quickly and accurately determine ultratrace elemental levels in selected reagent grade chemicals.” The company performed the analysis using procedures developed by the ACS. Results were then compared with ACS specifications.

Leeman Labs is a pioneer in the ICP spectrometry industry, and we were the first to use an Echelle spectrometer for ICP-OES. Recently we added our new Prodigy Plus High Dispersion ICP Spectrometer to our family of ICP-OES instruments. The Prodigy Plus builds upon our legacy and experience, while incorporating new state-of-the-art technology.