Column: Atomic Perspectives

Our Daily Dose of Poison: A Look at Lead in the Food Supply

October 01, 2017

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.

Using XRF as an Alternative Technique to Plasma Spectrochemistry for the New USP and ICH Directives on Elemental Impurities in Pharmaceutical Materials

July 01, 2017

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

Laser Ablation and Inductively Coupled Plasma–Time-of-Flight Mass Spectrometry—A Powerful Combination for High-Speed Multielemental Imaging on the Micrometer Scale

May 01, 2017

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.

Single-Particle ICP-MS: A Key Analytical Technique for Characterizing Nanoparticles

March 01, 2017

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.

New Approaches in Sample Preparation and Precise Multielement Analysis of Crude Oils and Refined Petroleum Products Using Single-Reaction-Chamber Microwave Digestion and Triple-Quadrupole ICP-MS

October 01, 2016

John Casey
Yongjun Gao
Weihang Yang

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.

Optimization of ED-XRF Excitation Configuration Parameters to Determine Trace-Element Concentrations in Organic and Inorganic Sample Matrices

July 01, 2016

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.

The Importance of Method Development for Trace-Element Analysis by Inductively Coupled Plasma–Optical Emission Spectroscopy

May 01, 2016

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.

Replacing Traditional Heavy Metals Testing with Modern Plasma-Based Spectrochemical Techniques

March 01, 2016

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.

Approaches to Maximize Performance and Reduce the Frequency of Routine Maintenance in ICP-MS

October 01, 2015

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

Handheld X-ray Diffraction for Remote, Field-Based Applications

July 01, 2015

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.