Columns | Column: Sample Prep Perspectives

Mary Ellen P. McNalley's latest "Sample Prep Perspectives" column demonstrates that AMGS, AGREE, and SPMS each quantify analytical greenness through distinct but complementary lenses—solvent/instrument energy demand, the full 12-principle GAC framework, and sample-preparation-specific sustainability, respectively—giving chromatographers practical, easy-to-use tools to benchmark and iteratively reduce the environmental footprint of their methods with measurable, reproducible scores.

Because sample preparation uses the most solvents, it is typically the least environmentally friendly step of the process. While completely eliminating sample preparation is the ideal "green" scenario, it is rarely practical. Therefore, over the next few columns, "Sample Prep Perspectives" will evaluate various tools developed over the past decade to gauge the sustainability of these methods, with the ultimate goal of helping the scientific community adopt a universal, practical standard for measuring analytical "greenness."

In recent years, analytical chemists have increasingly adopted a sustainability viewpoint. Yet, at the same time, they still use traditional organic solvents for extractions and other procedures. In this installment of Sample Preparation Perspectives, we will look at solvent selection from green considerations. Trends on solvent use are presented, followed by a discussion on what makes a green solvent. Finally, the CHEM21 Solvent Selection Guide is examined as representative of tools for selecting green solvents for use in analytical methods and other chemical processes.

This article reports on new products introduced at Pittcon this year and in the preceding year related to sample preparation instruments, supplies, and accessories.

This article describes the current highlights of using molecular imprinted polymers (MIPs) in sample preparation.

This installment examines a sample preparation survey, focusing on sample sizes, laboratory techniques used, automation, the use of solid-phase extraction (SPE) devices (cartridges, disks, plates, tips), SPE chemistries and selection criteria, and problems encountered in SPE.

In this article, the author reports the results from a survey of trends in sample preparation techniques.

An examination of the principles behind “salting out,” and when it can be applied in analytical extractions to enhance the extraction yield.

Here's the scoop on the latest offerings in sample preparation.

On a fundamental level, equilibrium and diffusion define chemical separations. Practical applications of partition coefficients to chromatographic sample preparation illustrate this point.

Continued development of needle-trap extraction (NTE) has expanded its versatility in applications such as disease diagnosis, aerosol-bound analytes, and breath analysis.

Test your knowledge of octanol-water partition coefficients and practical applications of sample preparation.

Can you pass this test of chromatographic sample preparation concepts?

We assess the landscape of new sample preparation instrumentation, supplies, and accessories introduced over the past 12 months.

The QuPPe method expands on QuEChERS to tackle highly polar compounds.

QuEChERS has been updated to suit modern instrumentation. Now also “efficient and robust,” QuEChERSER is a “mega-method” that covers a wider polarity range.

We explore the aspects of sampling that are of highest importance in an analytical scheme. Devices and processes for obtaining appropriate samples outside of the laboratory are presented.

We look at five modern treatments of chromatographic sample extraction, explaining their initial conception and development to shed light on their current roles as analytical tools.

These seven case studies capture and expand on lessons presented at ChromTalks.

We assess the landscape of new sample preparation instrumentation, supplies, and accessories introduced over the past 12 months.

Sorbent-based extractions using metal-organic frameworks (MOFs) have several advantages, notably selectivity. How do these extractions work, and where are they most useful? We look into the current state of the art.

Temperature is frequently employed to enhance analytical extractions, especially with solid samples or volatile analytes. Using temperature to enhance analytical extractions continues today with more recently developed techniques, which we explore.

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.

Our annual review of the new sample preparation instrumentation products introduced in the past year.

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

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.

To better understand modern sample preparation techniques-such as ultrasound-assisted extraction, microwave-assisted extraction, and pressurized solvent extraction-we should look at the lessons these methods took from Soxhlet extraction.

Our annual report of sample preparation instrumentation, supplies, and accessories for gas and liquid chromatography

Bioanalysis with SPME has advanced greatly over the past decade.