Columns | Column: Atomic Perspectives

This month’s column evaluates the capability of inductively coupled plasma–mass spectrometry (ICP-MS) to reduce the impact of doubly charged rare-earth element (REE) interferences on the quantitation of the metalloids, arsenic (As), and selenium (Se) in water and biological matrices.

In this article, we introduce the concept of a gas exchange device (GED) and how it can be used to monitor organometallic compounds and metallic particles in specialty gases.

This article explores the current landscape of global critical raw materials (CRM) trends in research and the applications of atomic spectroscopy (AS), including inductively coupled plasma–mass spectrometry (ICP-MS), inductively coupled plasma–optical emission spectrometry (ICP-OES), and X-ray analytical techniques in their identification of diverse industrial and environmental media.

This article explores the current landscape of global critical raw materials (CRM) trends in research and the applications of atomic spectroscopy (AS), including inductively coupled plasma–mass spectrometry (ICP–MS), inductively coupled plasma–optical emission spectrometry (ICP–OES), and X-ray analytical techniques in their identification of diverse industrial and environmental media.

In this review article, the editors of Spectroscopy break down the most recent research and trends using inductively coupled plasma mass spectrometry (ICP-MS).

A new sample introduction method improves ICP-OES for ultratrace element analysis. An explanation of how this ICP-OES compares to ICP-MS analysis is also provided.

Minimizing sample preparation issues requires users to consider method LODs as well as high purity polymer materials for sample collection and preparation. Here, we examine proper personal analytical practices one can take to avoid environmental contamination.

Good sample handling practices that minimize sample contamination during preparation of inorganic analyses are discussed, using glass and low purity quartz as examples.

The use of ICP-MS is constantly expanding into an ever-wider variety of applications. We assess the current landscape and where the technique is going in the future.

Is ICP-MS instrumentation ready to handle the requirements of AOAC Method 2015.01 for the determination of toxic elements in food—including dealing with interferences? We ran this study to check.

Understanding the proper ways to plan, run, and report proficiency tests will help you avoid errors and contamination.

Proficiency testing (PT) can assess the performance of individuals or laboratories, but it’s important to understand how to do it properly.

Laser ablation laser ionization time-of-flight mass spectrometry (LALI-TOF-MS) can quantify elemental constituents without the need for matrix-matching, making it attractive for metals testing, particularly for additive manufacturing.

How can you assess real-world detection capability of an ICP-MS system?

The way the analytical signal is managed in ICP-MS has a direct impact on the results generated. In this first of a two-part series, we explain the fundamental principles of a scanning quadrupole and how measurement protocols can be optimized based on data quality objectives.

A recent investigation found dangerous levels of heavy metals in commercial baby foods. Tighter scrutiny and regulations are needed.

EPA Method 200.8 and the Lead and Copper Rule Revisions don’t allow use of modern ICP-MS technology with a collision cell. Instead, correction equations can be used to compensate for polyatomic interferences.

Analysis of heavy metals in pet food using ICP–OES was conducted to determine if there were potentially toxic elements present. Many of the samples showed significant concentrations of various toxic metals.

This method detects elements intrinsically present in cells, and because sc-ICP-TOF-MS measures a full mass spectrum, no analytes are missed.

For a number of elements, spectroscopic interferences can have a significant impact on the ability to achieve low detection limits in ICP-MS. We investigate the mechanisms in multi-quadrupole ICP-MS that are designed to remove these interferences.

Recent advances in laser ablation laser ionization TOF mass spectrometry (LALI-TOF-MS) are allowing laboratories to reach required limits of quantitation for trace impurities in solid materials by direct analysis, while avoiding common limitations of other techniques.

By placing a liquid particle counter in-line with an ICP-OES system it is possible to analyze wear metals and particles in lubricant samples in one run. This approach streamlines the monitoring of in-service lubricants and meets the ASTM D5185 standard. Such analyses are critical for heavy machinery maintenance.

A laminar flow box for sampling is combined with a positive voltage on the skimmer cone to reduce detection limits to pg/L concentrations in ICP-MS. These improvements reduce the risk of contamination and increase the efficiency of ion sampling and focusing.

A detailed look at the most critical component of an ICP-MS instrument: the interface cones

Complex isobaric and polyatomic spectral interferences can be mitigated using triple quadrupole ICP-MS (ICP-MS/MS) with a collision–reaction cell (CRC). This configuration allows for the multielement characterization and detection of smaller nanoparticle sizes.

Illegal artisanal gold mining using mercury amalgamation is poisoning people and the ecosystem in the Amazon rain forest. By taking the technique of direct mercury analysis to a remote, field-based laboratory, the team of Professor Luis Fernandez is measuring the extent of the contamination in a wide variety of samples, including soil, fish, air and human hair.

With analytical advances, the clinical practice threshold for lead has dropped from 60 to 5 μL/dL.

This study explores the possibility of measuring the metal content of crude oils using EDXRF in samples as received in both the direct and indirect excitation mode.

A look at the implementation of the new United States Pharmacopeia (USP) chapters and the International Conference for Harmonization (ICH) guidelines for elemental impurities from an historical perspective, providing insight into the changes and considering the challenges and opportunities that lie ahead as the industry embraces the new methodology.

How to select the optimum atomic spectroscopic technique for orally delivered drugs, based on the J-values described in the validation protocols outlined in USP Chapter

How much lead is in our daily lives? We take a look at current research concerning lead in the United States food supply and investigations using ICP-MS into the measurement of high concentrations of lead in food.

An evaluation of the ability of XRF spectrometry to perform elemental impurity analysis of 12 elements in various pharmaceutical materials

Over the last few decades, elemental imaging using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has emerged as an important tool in the study of solid samples from a variety of scientific disciplines, including medicine, biology, and geology. This article highlights recent analytical trends towards high-speed, high-spatial resolution, multi-elemental imaging that became possible with advances in both LA and ICP-MS technology, including the design of fast-washout ablation cells and commercialization of high-speed ICP-MS such as time-of-flight mass analyzers (TOFMS), This study will demonstrate the new imaging approach by coupling LA with an-ICP-TOFMS system (icpTOF from TOFWERK, Thun, Switzerland) on two application areas: quantitative mapping of trace elements in a sulfide mineral (sphalerite), and imaging of the distribution of a chemotherapy drug (Cisplatin) in a rat kidney. High-performance LA-ICP-TOFMS provides researchers with an effective new tool to study biological and geological processes, with much greater speed and in much greater detail than previously possible with conventional ICP-MS instrumental designs.

The National Nanotechnology Initiative defines engineered nanomaterials (ENM) as those with dimensions of 1–100 nm, where their unique characteristics enable novel applications to be carried out. ENMs often possess different properties than their bulk counterparts of the same composition, making them of great interest for a broad spectrum of industrial, commercial, and health care uses. However, the widespread application of ENMs will inevitably lead to their release into the environment, which raises concerns about their potential adverse effects on the ecosystems and their impact on human health.

October’s AP column highlights a team of geochemists at the University of Houston who have been developing methods to streamline multi-element analysis for a more complete fingerprinting of oils by using one sample preparation method utilizing a single reaction chamber microwave digestion system and then analyzing these solutions for major, and minor elements by ICP-OES and low abundance trace elements by triple quadrupole (QQQ) ICP-MS. Results to date using this approach have shown that complete elemental recovery and removal of organic matrices can be achieved safely and that up to 57 elements can be determined in oils with good accuracy and precision. Removal of organic matrices during digestion not only helps to limit the formation of polyatomic spectral interferences, but improves instrument stability and reduces carbon build in the sample introduction and interface regions, which have traditionally plagued “dilute and shoot” methods.

This month’s column will describe a novel ED-XRF system, which utilizes a combination of a Bragg polarizer, used simultaneously with a direct excitation source, together with a novel, highly annealed pyrolytic graphite (HAPG) crystal as a band-pass filter. By selection of the optimum configuration, it will allow for high precision of minor and major elements across a wide wavelength range and/or lower detection capability for smaller groups of elements from potassium to manganese. To show the practical benefits of this technology, this study will focus on these performance metrics for the determination of titanium in polymer samples, together with the multielement analysis of high purity graphite using the ashing sample preparation method. In particular, it will be shown that the improved performance for graphite will allow for lower sample weights to be used resulting in significantly shorter ashing times, which is a requirement for high sample workload laboratories and process control applications.

Selecting the correct wavelengths or isotopes and optimizing flame, furnace, or plasma conditions can seem a daunting task for a novice user, with a multitude of opportunities to introduce errors and generate poor quality data. While most elemental analysis instruments have intuitive operating software, they lack the intelligence to guide the operator through the early stages of method development and overcome associated problems along the way. This study describes an automated, intelligent approach to method development for trace element analysis using optical emission spectroscopy, and exemplifies this capability with a suite of real-world sample matrices.

This month’s column presents an overview of the new 11th edition of the ACS Book of Reagent Chemicals and discusses some of the updated methods, and new procedures being adopted. In particular, we focus on new plasma based spectrochemical methodologies for the determination of heavy metals in reagent chemicals, which have replaced the 100 year-old test using precipitation and colorimetric measurement of the metal sulfides.

This article offers some suggestions for routine maintenance and offers guidance to troubleshoot common problems encountered in the ICP-MS sample introduction area.

This installment describes the development of two novel X-ray diffraction (XRD) techniques that enable the rapid analysis of samples using handheld instrumentation for remote applications. Both techniques can be applied to unprepared samples in the field, which is a highly favorable characteristic in many applications since the time required for laboratory-based sample preparation is avoided.

A novel adaptation to inductively coupled plasma–mass spectroscopy (ICP-MS), mass cytometry provides researchers with a tool to study the complexity of biology at the single-cell level.

This installment evaluates the application requirements for the determination of 15 elemental impurities in pharmaceutical materials as described in the new United States Pharmacopeia (USP) Chapters and and offers suggestions about which atomic spectroscopic technique might be the most suitable to use.

An application of atomic spectroscopy for experiential learning through archaeological investigations is presented.

A new sodium peroxide fusion method is described, as well as the conditions for inductively coupled plasma–optical emission spectrometry, and a list of the accuracy and precision measurements for all prepared samples.

A critical review of the main developments in instrument technology, calibration, and sample preparation that have made it possible to determine low sulfur concentrations in fuels followed by a discussion of strategies to minimize spectral interferences related to sulfur determination by ICP-MS, such as collision–reaction cells, high-resolution mass analyzers, and the interference standard method.

Evaluation guidelines and important factors for laboratory scientists to consider when choosing an inductively coupled plasma–mass spectrometry instrument

The main areas of training necessary for a good foundation in the analytical methodology of XRF spectroscopy are discussed.

A case study demonstrating the use of an ICP-MS system to detect low levels of beryllium in urine, using a simple but highly sensitive method

A historical account of Talbot's contributions to spectroscopy

ICP-OES can provide assistance in setting up an EPA 200.7 soil analysis method.

How to reduce plasma-, matrix-, and solvent-induced polyatomic interference by bleeding a collision–reaction gas into the tip of the interface skimmer cone

This tutorial on the chemical principles involved in dissolution, stability, and matrix components will help you successfully analyze a broad spectrum of metal analytes with ICP-MS using liquid introduction or flow injection.

For any given spectrometric system with a defined resolution and excition results, the background equivalent concentration is a characteristic of spectral lines.

Wastewater from coal-fired power plants is linked to a wide range of environmental and human health concerns. Measuring low levels of toxic trace metals in these wastewaters is complicated, however, by high levels of interfering matrix elements. A new EPA method using ICP-MS addresses this analytical challenge.

The advantages and disadvantages of measuring mercury with cold vapor atomic absorption spectroscopy, cold vapor atomic fluorescence spectroscopy, and direct analysis by thermal decomposition are explained.

Here are nine suggestions for improving this valuable technique.

Most analytical measurements performed by either inductively coupled plasma–optical emission spectrometry (ICP-OES) or ICP–mass spectrometry (MS) require accuracy and precision, which are essential for obtaining correct answers. However, all modern ICP-OES and ICP-MS instruments have the ability to perform semiquantitative analyses. This seems strange since accuracy is important, but semiquantitative analysis does have a role in analytical measurements. This article will explore why semiquantitative analysis is important and will look at various ways it can be performed and implemented.

The USP proposes the use of analytical techniques capable of measuring impurities at the specified limits with optimal selectivity, sensitivity, simplicity, and robustness.

ICP-MS is powerful technique capable of measuring very low levels in a wide variety of sample types, limited only by cleanliness and the presence of interences. This article will examine the types of interferences that are encountered and various ways of dealing with them using a quadrupole ICP-MS instrument: mathematical correction equations, matrix removal, and cell-based ICP-MS. The strengths and limitations of each method will be discussed.

While viewed as a mature technology, atomic absorption is still an attractive choice, particularly in the area of food safety.

Guest authors Steve Wilbur and Ed McCurdy discuss the role of qualifier ions in ICP-MS research in this month's installment of "Atomic Perspectives."

This article is a follow-up to an earlier "Atomic Perspectives" column on the spectral lines of hydrogen (1).

Speciation analysis by LC-ICP-MS has been growing rapidly in popularity and application over the past several years. Not only have people begun looking at different elements and species, but there has also been an increase in the variety of matrices that speciation analysis is being performed on.

One of the most difficult tasks in any laboratory is the validation and assurance of all data being reported. Whether or not this is being mandated by a regulating agency, it is imperative that the quality of data from any analysis be controlled. How do the laboratory workers ensure the quality of their reported analyses and how do they demonstrate this quality?

Volker Thomsen takes a look at the impact that the discovery of X-rays by Wilhelm Röntgen in 1895 has had on the world.

Guest columnist Steven Wilbur discusses the elemental nature of ICP-MS and its strength as a universal quantifier, an aspect of the technique he believes has not received enough attention.

The authors discuss speciation analysis methods that enable scientists to identify and measure the quantities of one or more individual chemical species in a sample.

A short history of the early scientific developments related to the optical emission lines of hydrogen is presented. These were crucial to the development of the quantum theory. Balmer's empirical formula was an important milestone. Rydberg and others provided additional work, especially for higher atomic numbers. However, it remained for Bohr to provide the physical reasoning.

While inductively coupled plasma-mass spectrometry (ICP-MS) is capable of part-per-quadrillion (ppq) detection limits under ideal conditions, most applications do not require this level of sensitivity and do not justify the cost associated with achieving it. Practical sensitivity in ICP-MS is determined not by instrument signal-to-noise ratio, but rather by controlling interferences and matrix effects in real samples. Understanding the sources of these effects and their management is critical in determining the most practical way to achieve specific data quality objectives.

Speciation analysis has grown rapidly and has expanded to a variety of markets, including environmental, clinical, food, nutraceutical, and bioanalytical. This growth has resulted from the realization that knowing the total amount of an element does not always provide adequate information for assessing health and environmental effects, but knowing which form of the element is present presents a much more comprehensive picture.

Simple, fast, and reliable on-site hydraulic oil analysis should be an integral part of any preventative maintenance program. Since the majority of machine failures are contamination related, it is important to analyze the hydraulic fluid to monitor equipment condition and identify machine wear. Significant cost savings can result from early identification of machine failure, oil quality, handling and other problems. Oil analysis can detect changes in oil quality, contamination, wear and chemical differences. Benefits of this information include prolonged equipment life, reduced equipment downtime, and reduced overall maintenance costs. In addition, plants can increase intervals between oil changes, thus reducing waste oil, maintenance, and oil purchase costs.

The RoHS/WEEE directive requires the electronics industry to certify that products comply with maximum concentration amounts of particular elements and compounds (Cr VI, Pb, Cd, Hg, Br PBB/PBDE) by July 2006. Instrumentation must be developed to perform the certification.