Douglas E. Raynie

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 yearly report on new products introduced in the preceding year, since March 2023, covers sample preparation instrumentation, supplies, and accessories.

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.

Results from our recent survey on sample preparation techniques uncover trends in the field over the last generation and their impact going forwards.

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

On a fundamental level, equilibrium and diffusion define chemical separations.

This yearly report on new products introduced at Pittcon and in the preceding year covers sample preparation instruments, supplies, and accessories.

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.

These questions tend to focus on dealing with octanol-water partition coefficients, as well as more practical applications of sample preparation.

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

As I write this, I’m also grading the final exam from my Chromatography and Separations course. Here’s your opportunity to test yourself; answers are provided.

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.

Sample Preparation Perspectives’s yearly report on new sample prep products introduced in the preceding year.

This month we’ll take a look at Quick Polar Pesticides (QuPPe), comparing and contrasting it with QuEChERS and noting how we can learn from previously developed methods as we strive for improvements.

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

This column has discussed both sample size and homogeneity previously. However, sample collection is just as important. Too often, analysts are dependent on clients bringing the sample to the laboratory. This month, we take a look at devices and processes for obtaining samples outside of the laboratory.

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.

In this column, importance of the knowledge of the fundamental principles underlying sample preparation is emphasized.

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.

This yearly report on new products introduced in the preceding year, since March 2020, covers sample preparation instrumentation, supplies, and accessories.

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

A review of cutting-edge analytical extractions using metal-organic frameworks (MOFs), including a description of what MOFs are, their preparation, principles of use, advantages, and application areas.

The application of temperature is frequently employed to enhance analytical extractions, especially with solid samples or volatile analytes. This article explores the role of temperature in analytical extractions.

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 impacts solubility, diffusion, surface tension, and more. It can potentially lead to solute decomposition. This month we will explore the role of temperature in analytical extractions.