Sample Preparation

Which key efficiency techniques can maximize your analytical goals? This instalment of the LCGC Blog begins by describing the principles and optimization of liquid-liquid extraction (LLE).

It is important to develop analytical methods to detect crude MCHM components in environmental water samples. This article describes two microextractive methods based on solid-phase microextraction (SPME) in fibre format and thin film microextraction (TFME) that were developed and validated for 4-MCHM and other constituents of crude MCHM.

This article reviews how nanomaterials are being used in a variety of sample preparation techniques, such as dispersive solid-phase extraction (dSPE), solid-phase microextraction (SPME), stir-bar sorptive extraction (SBSE), and matrix solid-phase dispersion (MSPD).

The analysis of contaminants found in environmental waters and originating from personal care products using metalorganic frameworks (MOFs) combined with liquid chromatography (LC) is described. This work expands the use of MOFs from gas chromatography to LC and also meets the requirements of green analytical chemistry.

A simple method for the analysis of leachables using solid-phase microextraction (SPME) and comprehensive two-dimensional gas chromatography, coupled to mass spectrometry (GCxGC–MS). This fully automated method bypasses the use of solvents and excessive sample handling. Four potential leachables were tentatively identified.

Douglas E. Raynie explores formal and informal training opportunities that may be available to educate all chemists in the fundamentals of necessary laboratory sample preparation skills.

Oliver Napoleon Hill (1883– 1970) was an American self-help author once described as ”the most famous conman you’ve probably never heard of” (1 ). Conman maybe, but there is a quote of his that I believe to be particularly true when considering sample preparation for chromatography techniques; ”The one who tries to get something for nothing generally winds up getting nothing for something.”

In electromembrane extraction (EME), the target analyte is extracted from an aqueous sample across a supported liquid membrane (SLM) and analyzed using LC. Through the study presented here, we demonstrate the principles of the technique and test its performance.

When working with complex samples, we need effective approaches to deal with matrix interferences. Here, we outline methods of sample preparation, on-line sample treatment, and instrument tools that can help. We also provide examples of applications and guidance for how to evaluate the best option for your complex sample.

This selection of influential recent papers on chromatographic sample preparation gives us a sense of important developments.

A top-down approach to quantifying intact proteins from biological fluids using liquid chromatography–triple quadrupole–mass spectrometry (LC–MS/MS) offers the potential for more absolute quantitation than bottom-up approaches. To make this broadly viable, however, commercial sample preparation tools are needed.

Paper-based sorptive phases are promising tools in sample preparation because of their high surface-to-volume ratio, porosity, and versatility. This article discusses the synthesis of paper-based sorptive phases by dip coating. This procedure has allowed a wide variety of phases coated with polymers, nanoparticles, and their combination to be synthesized. This article presents the synthesis, types of coatings, and extraction devices, to highlight the versatility and potential of these materials to the analytical community, particularly for sample preparation.

Sampling can be the most demanding part of an analysis. Anybody in charge of sampling needs a good understanding of the composition of the material to be investigated, its heterogeneity (or homogeneity, in simple cases), and the chemical properties of the analytes. Sampling procedures must be described in detail. Detecting the bias of a sampling procedure can be difficult; this fact is trivial, but it must not be forgotten.

Click the title above to open The Chromatography & Sample Preparation Terminology Guide special issue in an interactive PDF format.

The improved performance of chromatographic detectors, most notably mass spectrometers (MS), has enabled many advances in analytical science, however, one such advance may be given less prominence than perhaps it should.

A new technique, ICE concentration linked with extractive stirrer (ICECLES), provides highly efficient isolation of trace compounds from aqueous samples. ICECLES combines freeze concentration with stir-bar sorptive extraction into a seamless analytical extraction methodology.

Proper sample preparation is vital. We look at formal and informal training opportunities to educate chemists in the fundamentals of sample preparation skills.

Bioanalysis with SPME has advanced greatly over the past decade.

Traditional sample preparation method development can often be laborious and costly. Understanding the underlying concepts of the technique can help food and environmental laboratories develop methods in notoriously complex matrices, faster, more efficiently, and provide better chromatography. With the presence of many unique matrices and analytes, methods such as QuEChERS, supported liquid extraction (SLE), or solid-phase extraction (SPE) provide the necessary adaptability for many types of extractions. With customizable methods to work with unique matrices and with the addition of automation, extractions can be improved to save time and provide consistent recoveries.

Whether or not headspace sampling is quantitative depends on the information gleaned from the analysis

Our yearly report on new products covers sample preparation instrumentation, supplies, and accessories. New sample preparation technologies introduced in the past year, while not necessarily disruptive, take giant leaps in that direction.

A snapshot of key trends and developments in the chromatography sector according to selected panellists from companies who exhibited at Analytica 2018.

A look at recent advances in SPME, such as increasing the sorbent surface area available for extraction, accommodating direct analysis by mass spectrometry, and sorbent overcoating to resist fouling by sugars and lipids

Click the title above to open the LCGC North America February 2018 Chromatography and Sample Preparation Terminology Guide, Vol 36 No s2, in an interactive PDF format.

Part I of this series on practical perspectives of data integrity focuses on sample management, transport, and preparation.