New Sample Preparation Products and Accessories for 2024

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

Our annual review of sample preparation products covers the previous year, since March 2023. It is becoming increasingly more difficult to identify new products. The trend of vendors avoiding exhibiting at general analytical conferences in favor of more focused meetings continues, and they are increasing their marketing via social media or other digital means. In late 2023, the LCGC staff submitted a survey to vendors of sample preparation products. Responses to this survey are compiled in this review, as are new product introductions during the past 12 months noted via direct mailings, email, and other means. Additionally, vendors at the 2023 Eastern Analytical Symposium and Pittcon 2024 were perused. Themes that emerged during sample preparation product development include headspace sampling, solid-phase extraction (SPE) techniques, and approaches toward greener analysis.

In this review, we will discuss instrumentation for sample preparation, SPE, and sample preparation consumables. Tabular summaries for each product category are provided.

Sample Preparation Instrumentation and Accessories

Perhaps the most extensive new product introduction was an extension of green headspace analysis by Entech Instruments, building off its Sorbent Pen line and vacuum-assisted headspace sampling. These are marketed as Vacuum Assisted Sorbent Extraction (VASE), Flash-VASE, and Full Evaporative Vacuum Extraction (FEVE). Combined with the rest of the Entech family of products, the company claims to optimize recovery of volatile compounds (that is, gas chromatography [GC]-compatible compounds) based on the sample matrix of interest (both liquids and solids) and the volatility range of the compounds of interest. VASE allows extractions from ambient temperatures up to 70 °C under static vacuum conditions that are often at full equilibrium. Vial sizes from 20 to 125 mL are used. Meanwhile, Flash-VASE extends the extraction temperature range up to 280 °C and uses 2–20 mL vials to achieve a more rapid extraction. Both techniques may extract compounds up to a boiling point of 500 °C. This analyte boiling range is extended to 600 °C with the FEVE technique. In FEVE, smaller vials (2–6 mL) are utilized with extracts at 30–40 °C to remove the volatile matrix, followed by extraction at 50–280 °C. These conditions allow FEVE to accommodate volatile liquid matrices with low solid content. Depending on the choice of extraction mode, an analyte volatility range of -50 to 600 °C is attained, greater than that found with other headspace methods, with higher recoveries. However, it should be noted that headspace composition varies with applied temperature and pressure, so analysts must diligently consider the goals of their analysis, for example flavor aromas versus more exhaustive compositional analysis. Getting back to Entech’s roots, a SkyCan Autosampler was also introduced for canister sampling in air monitoring studies. Part per trillion detection of airborne compounds may be achieved with 1.4-L canisters.

Continuing with the theme of greener (solventless) thermal desorption and headspace techniques for analysis of volatile and semivolatile organic compounds are new product releases from Markes International and Gerstel. The Markes TT24-7 NRT is introduced for the near real-time determination of airborne chemical warfare agents and toxic industrial chemicals. Two focusing traps in the system work in tandem to create conditions for 100% data capture. Trapping at temperatures as low as -30 °C combine with backflushing and an optimized flow path for quantitative determination of nerve and blister agents and related compounds. The cryogen-free system combines with most standard GC and GC–Mass Spectrometry (GC–MS) systems for monitoring in remote, mobile, or discreet locations. Gerstel also offers cryogen-free trapping, called Dynamic Focusing, with its thermal desorption unit to provide improved accuracy and precision in the analysis of very volatile organic compounds (VVOCs), volatile organic compounds (VOCs) and semivolatile organic compounds (SVOCs). The trap liner of the Dynamic Focusing system uses a weak sorbent at -10 °C for trapping. VVOCs are very weakly retained to allow focusing as a sharp injection band in subsequent GC. VOCs and SVOCs require heating of the trapping sorbent in the second stage of desorption. The Gerstel PYRO-Core system accommodated sample pyrolysis at temperatures up to 1000 °C. Ramped pyrolysis provides additional chemical information from solid and liquid samples.

A more comprehensive sample preparation workstation is delivered in the ePrep ONE system. The workstation provides most liquid handing functions, including sample aliquoting, addition of diluents, reagents, surrogates, and standards, serial dispensing and dilution, and volume adjustment, as well as magnetic stirring, SPE, and liquid-liquid extraction (LLE). The system handles five to 200 samples with transfer to autosampler racks.

Ancillary sample preparation accessories are also featured in 2023. Two systems address sample comminution. The newest in Fritsch’s Pulverisette cutting mills, the Pulverisette 29 Mini Cutting Mill, is designed for fast milling of small sample volumes (up to 100 mL) down to 0.25 to 6 mm. Easy cleaning helps maintain sample integrity for processing of medium-hard, soft, brittle, tough, fibrous, tough-elastic, and temperature-sensitive samples. The PreOmics BeatBox provides tissue homogenization and cell lysis of 1–50 mg samples in a 96-well format. Maximum protein release in ten minutes renders the system compatible with subsequent liquid chromatography–MS (LC–MS) analysis. A BeatBox Bead Remover accessory removes the GYUTO beads for downstream liquid handling.

Table I summaries the newly introduced sample preparation instrumentation and accessories.

TABLE I: Sample preparation instrumentation and systems.

Solid-Phase Extraction

Since last year’s review of solid-phase extraction products, the largest focus of new developments has been in the direction of preparation techniques for proteomics and biological samples.

Last year, CDS Analytical introduced micropipette tips using the Empore technology. Since then, the product line has expanded significantly, not only offering the pipet tips in 10- and 200-µL sizes but also a 500-µL spin column, a 3-mL cartridge, and a 1.2-mL 96-well plate. These products offer the diversity to handle a wide variety of sample types in terms of volume, quantity, and size. Labeled as the E3 series, the glass bead-based technology has the capability to do sample preparation in a single vessel, including filter-based sample processing, general shotgun proteomics, clinical proteomics, and biomarker discovery. CDS Analytical also announced a new centrifuge-ready spin column series for proteins and peptide applications, consistent with their other Empore products. They are made of a low-binding polypropylene material and are chemically resistant to organic solvents as well as acid and base conditions. The sorbents are high density C8 and C18 phases, cation and anion exchange phases, and mixed-mode styrene-divinyl benzene phases.

MAC-MOD Analytical launched a new line of SPE products for omics clean-up, LC-UV background improvement, and high-throughput assays, called MemBrain. These products also come in cartridges, extraction tips, disks, and 96-well extraction plates. A touted feature of these products is that there is no silica bed to disrupt. Instead, because these are membranes, uniform distribution of analytes of interest is achieved. The membranes can be mixed and matched to optimize the extraction for a particular application, and the plate format allows for high-throughput screening for unknown mixtures. The choice of bonded phase is broad; beyond reversed-phase and ion-exchange, chelating phases are also available. PreOmics GmbH launched sample preparation kits for proteomic sample preparation for high through-put LC–MS analysis. This new line of products includes ENRICH-iST 8x, ENRICH-iST 96x, and ENRICH-iST 96x HT. These ENRICH-iST kits contain all the core components to perform a complete proteomic sample preparation: protein enrichment, alkylation, reduction, digestion, and peptide clean-up. The enrichment phase of the workflow uses EN-Beads, a paramagnetic bead, to take low-abundant proteins while conserving proteome coverage. The kits are focused on the use of mammalian plasma or serum samples and are optimized for low input, 20-µL samples, large-scale proteomic studies.

Two new SPE products for proteomics and biologicals were announced by Waters Corporation. The first, developed to purify, desalt, and buffer exchange proteins above MW 5000, is designed especially for desalting of denatured, reduced, and alkylated proteins prior to tryptic digestion. These conventional SPE cartridges have a cross-linked dextran base and can be used in a manual or automated workflow stream. The cartridges, part of the well-known and established SEP-Pak family of cartridges, are simply called SEC Desalting Cartridges, are 1 cc in size, and have been quality tested to obtain greater than 80% protein recovery. The second product introduced by Waters is the OligoWorks SPE Microplate Kit. This kit is in a standard 96-well plate format and is a detergent-free proteinase K sample pretreatment system which uses a weak anion exchange extraction phase. The resultant concentrated low-volume eluate produced can be directly injected into an LC–MS.

From a sustainable perspective, CTC Analytics has developed a new PAL system for Micro-SPE cartridges, a miniaturized and robust automated SPE system that uses less sample and less solvent with equivalent performance to conventional-size SPE cartridges. The PAL tool which sits on top of the cartridge consists of a syringe and a needle guide. The cartridge is two parts, the inert polymer material and the sorbent material. The bottom outlet of the cartridge is designed to penetrate pre-slit septa of a GC or deliver directly into an LC injection port. The cartridge can withstand high pressure, up to 10 bar, and prevent leakage around the syringe needle. Currently, it is only designed to inject into the PAL system liquid injection ports. The applications of this can be widespread. However, as of this writing, only QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) and strong anion-exchange phase µSPE cartridges are available.

As an alternative to traditional QuEChERS technology use of dispersive solid-phase extraction (dSPE) clean-up, Biotage advanced the methodology with the use of column solid-phase extraction (cSPE). Compared to QuEChERS clean-up, these cSPE cartridges offer a simplified procedure with fewer manual steps, cleaner extracts, and improved reproducibility along with automated processing options for improved accuracy. Since the QuEChERS method is considered landmark in pesticide residue analysis, it should come to no one’s surprise that developments will continue to be made to make it faster and more reliable. These cSPE cartridges are registered under the name ISOLUTE. Also, from Biotage, the Extrahera HV-5000 is a high-volume sample prep workstation, Good Laboratory Practice (GLP)-capable, and positive pressure-driven. It is dedicated to column-based SPE and supported-liquid extraction (SLE) consumable formats, and therefore goes hand in hand with the cSPE for QuEChERS clean-up described above. It caters to large sample volume cartridges of 3, 6, 10, and 15 mL and is capable of dispensing volumes from 250 to 5000 µL (0.25 to 5 mL) through four individual pipet tips. From a sustainability viewpoint, the instrument offers three-channel waste segregation for organic, aqueous, and chlorinated solvents. The instrument supports 12, 24, and 48 sample cartridge positions and has a collection carousel that allows for not only multiple waste, but also multiple elution, positions. Manual refilling can be eliminated with the five automatically refillable 40-mL solvent reservoirs. The applications of this system are broad; beyond QuEChERS, the application of EPA Method 1633 for 40 PFAS (per- and polyfluoroalkyl substances) in various environmental matrices via liquid-solid extraction analysis has also been demonstrated.

Another automated solid phase extraction elution unit, the EL870, has been presented this past year by GL Sciences. This instrument is equipped with a high-precision and reliable syringe pump that improves efficiency and accuracy via automation. It is equipped with a user-friendly key controller and accommodates up to six SPE columns while compatible with most organic solvents. This simple instrument aids in the obtaining high precision analysis in SPE for effective clean-up of biological, food, and environmental matrices prior to analysis by GC or LC.

The new product introductions in SPE are summarized in Table II.

TABLE II: Solid-phase extraction products.

Sample Preparation Consumables

Powered by microbubbles, the new Agilent Viral DNA/RNA wastewater prep kit has been created specifically for the purpose of the analysis of viral DNA and RNA in wastewater samples. The functionalized microbubbles break down the cell walls using nucleic acid binding to extract nucleic acids. No pasteurization or filtration is required with the use of the microbubbles, and shorter processing times can be achieved. The microbubbles themselves, provided by Akadeum Life Sciences, can be made of a variety of materials but generally have a shell constructed of polymers, lipids, or proteins, with a gas center. Microbubbles are nanometers, nm, to micrometers, µm, in size, so they are small, simple, and efficient. Using the principles of physics, microbubble sorting relies on buoyancy. The microbubbles allow for gentle transport of extremely small cells or particles. Where other sorting methods can alter or damage cells, microbubbles do not. Advantages of this microbubble technology include increased sensitivity to track a viral load within a community, smaller sample volumes which limit the infectious agents in the laboratory, and quicker turnaround times. The Viral DNA/RNA wastewater prep kit can capture SARS-CoV-2 viral RNA.

A released N-glycan labeling kit was created by Waters called the GlycoWorks RapiFluor-MS N-glycan Eco Labeling Kit. An application note defines the objective of this kit is to replace N,N-dimethylformamide (DMF) with the more environmentally friendly dimethyl sulfoxide (1). This has been suggested by the 2023 European Chemical Agency (ECHA) because of the detrimental effects of DMF on both the analyst and the environment. The report demonstrated a one-to-one equivalence of DMSO for DMF both as a solvent and a co-solvent in a manual and automated procedure of the GlycoWorks RapiFluor-MS N-glycan Eco Labeling Kit.

PeptideWorks Tryptic Protein Digest Kits were also presented by Waters since the last new product review. These kits for peptide mapping of biotherapeutic proteins can be used in both manual and automated procedures, yielding peptide fragments to further characterize specific peptide regions and modifications. They yield high-efficiency, reproducible peptide maps in less than 2.5 h. They can achieve a 78% reduction in missed cleavages as well as a 98% reduction in contaminated autolysis peaks. In addition, the kits aid in maximizing sensitivity while minimizing metal adsorption of acidic deamidated peptides in liquid chromatography with both UV and MS detection.

New from Sartorius are Safetyspace filter tips. Their uniqueness is simply the larger space between the sample and the filter than conventional filter tips. This space prevents the risk of sample absorption into the filter and avoids cross-contamination between samples and the pipette. Compatible with most commercial pipettes, they are certified to be free of DNase, RNase, and endotoxins. The tips are made of virgin polypropylene and the filters are polyethylene without any self-sealing additives. They are available in 10- to 5000- µL volumes.

Smart SPME (solid-phase microextraction) Arrows and fibers introduced this past year by Restek offer the same application, performance and longevity of other SPME formats (non-Smart Arrows and conventional fibers) with the added feature of a smart chip which tracks usage history, parameters, and ranges. While not all instruments are compatible with this new Smart SPME technology, they are however backward compatible with any generation of PAL3 systems. The Smart SPME Arrows and fibers require a different manual holder then the holder for non-Smart SPME devices. There are two diameter sizes for the SPME Smart Arrows, 1.1 mm, and 1.5 mm, distinguishable by color, as represented in Figure 1. Table III summarizes these sample preparation accessories.

FIGURE 1: Smart SPME Arrows and fibers from Restek with a smart chip which tracks usage history, parameters, and ranges. SPME Smart Arrows are available in two sizes, 1.1 and 1.5 mm, distinguishable by color.

TABLE III: Sample preparation accessories and related products.

Conclusions

In our recent survey of the state of sample preparation (2), we noted a strongly increasing trend toward greener approaches to sample preparation. This trend is observed in the new products introduced this year. Thermal desorption and headspace analysis eliminate the need for potentially hazardous solvents, while other improvements minimize solvent use or replace particularly objectionable solvents. When applied to emerging areas in bioanalysis and environmental analysis, we look for future sample preparation innovations to continue this trend.

References

(1) Koza, S. M.; Addepalli, B.; Hanna, C. M.; Lauber, M. A.; Shiner, S. Replacing DMF with DMSO in the Eco GlycoWorks™ RapiFluor-MS™ Labeled N-Glycan Sample Preparation; Application Note 720008157; Waters Corporation: Milford, MA, 2023. https://www.waters.com/nextgen/us/en/library/application-notes/2023/replacing-dmf-with-dmso-in-the-eco-glycoworks-rapifluor-ms-labeled-n-glycan-sample-preparation.html (accessed 2024-04-24).

(2) Raynie, D. E. Trends in Sample Preparation, Part II: Sample Considerations and Techniques. LCGC International 2024, 1 (3), 12–21. DOI: 10.56530/lcgc.int.mn3284n6

ABOUT THE AUTHORS

“Sample Prep Perspectives” editor Douglas E. Raynie is Professor Emeritus at South Dakota State University. His research interests include green chemistry, alternative solvents, sample preparation, high-resolution chromatography, and bioprocessing in supercritical fluids. He earned his PhD in 1990 at Brigham Young University under the direction of Milton L. Lee. Raynie is a member of LCGC’s editorial advisory board. Direct correspondence to: douglas.raynie@sdstate.edu

Mary Ellen McNally is an FMC Fellow at the Stine Research Center for FMC Corporation. Dr. McNally was named to the Analytical Scientist Power List as one of the Top 50 most influential women in the analytical sciences, has received the American Microchemical Society Steyermark Award in the field of microanalysis, the Chromatography Forum of Delaware Valley Award for contributions to the field of chromatography, and has been recognized for her contributions to the field of supercritical fluids by the Midwest SFC Discussion and the Tri-State Analytical Supercritical Fluid Discussion Groups.