Per- and poly-fluoroalkyl substances (PFAS) are a family of potentially thousands of synthetic compounds that have long been used in the manufacture of a variety of common products with stain-repellent and nonstick properties. Their signature strong fluorine and carbon bonds make them difficult to break down and, as a result, they are among the most persistent of today’s environmental pollutants. Alarmingly, PFAS can be found in drinking water and have been shown to accumulate in the body with the potential to cause multiple health problems, such as hormone disruption and cancer. Advances in mass spectrometry have facilitated the detection of known PFAS contaminants as well as the identification of poorly studied and novel compounds in watersheds. This article explores the detection of known and novel PFAS contaminants in aqueous film-forming foams and raw drinking water sources in North Carolina, using new advances in mass spectrometry and data acquisition to improve identification and quantitation.
The author configured a purge-and-trap GC-MS system that simultaneously improved chromatographic resolution and reduced analysis time.
Quantification of European Union (EU)-priority polycyclic aromatic hydrocarbons (PAHs) in plant matrices is a crucial task. Various methods for enrichment and preconcentration, such as the preloaded-pipette tip solid‑phase extraction (SPE) (1), are available. Nevertheless, analyte recovery as a result of homogenization, sample preparation, and extraction are rarely discussed in the field of phytopharmacy. This study deals with the recovery in dry plant extracts, which are typically used in phytopharmaceuticals and reflect the actual polycyclic aromatic hydrocarbon content in the commercially available end product (2). The aim of this study was to monitor benzo[a]pyrene, benzo[a]anthracene, chrysene, and benzo[b]fluoranthene loss of spiked samples as a result of commonly-used sample pretreatment, extraction, filtering, and evaporating techniques in 1:1 (v/v) cyclohexane–ethyl acetate primulae flos and sambuci flos dry extracts. Results showed that improper sample preparation can lead to false results. In the case of benzo[a]pyrene with a deviation of 155% from the theoretical true value.
Given the increasing number of chiral samples and the time constraints under which chromatographers work, choosing an appropriate chiral stationary phase for the resolution of enantiomers can be challenging. In this article, the authors describe a screening approach for chiral HPLC method development.
Separation and Characterization of Macromolecules 11 (SCM-11) will take place from 22–24 January 2025 in Amsterdam, The Netherlands.
GC and TLC methods are demonstrated for quantification of stigmasterol 3-O-β-D-glucopyranoside (S3G), the main active component in the herbal nutraceutical Balanites aegyptiaca, an antihyperglycemic in Egyptian folk medicine.
The efficiencies of microbore-2 columns, which are prepared from blanks that have a wide variety of inner surface roughness, drop sharply when the size of individual surface roughness features approaches the particle size of the packing material. The results suggest that two categories of packed column structure relate to the surface features and yield high and low efficiency columns. This installment of "Column Watch" discusses this conclusion in terms of the stability of an agglomerated layer of packing particles on the blank wall when subjected to shear forces during column packing.
We explore the impact of two different stationary phases and ion-pair reagents on the retention behavior of a therapeutic peptide using reversed-phase liquid chromatography. This information is of fundamental importance for the development of reliable, selective, and fast analytical methods able to separate and identify the target peptide.
A novel LC–MS/MS method, with a dual ESI and APCI source using simple solvent extraction for sample preparation, was validated for analysis of 102 pesticides and 5 mycotoxins regulated by Colorado state in dried hemp.
This paper proposes a new method of flash qualitative identification (FQI) to qualitatively identify a certain target component from a mixture within half a second by disusing the analytical column, which is a time-consuming unit in current chromatography instruments. First, a Noised Spectrum Identification (NSI) model was constructed for the data set generated directly by diode array detector (DAD) without the process in an analytical column. Then, a method called vector error algorithm (VEA) was proposed to generate an error according to the DAD data set for a mixture and a specific spectrum for the target component to be identified. A criterion based on the error generated by the VEA is used to give a judgement of whether the specific spectrum exists in the DAD data set. Several simulations demonstrate the high performance of the FQI method, and an experiment for three known materials was carried out to validate the effectiveness of this method. The results show that the NSI model concurs with the real experiment result; therefore, the error generated by the VEA was an effective criterion to identify a specific component qualitatively, and the FQI method could finish the identification task within half a second.
Reduce sample prep time by filtering your water samples in an auto sampler ready Thomson filter vial. These vials help reduce sample prep time and reduced materials needed.
A validated method was developed for screening short to long chain PFAS in industrial water, using direct injection with no sample preparation.
A new method has been developed to provide a sensitive, accurate and convenient GC–MS method to align with the new European regulation in relation to the introduction of the new Accutrace Plus marker for fuels.
The authors explore computer-aided workflows and machine learning, aimed at optimizing LC parameters, focusing on kinetic and thermodynamic aspects, and proposes closed-loop optimization strategies.
In this paper, two adeno-associated virus (AAV) genome integrity analysis workflows are introduced; a standard sample preparation protocol and an accelerated procedure, both utilizing capillary gel electrophoresis with laser induced fluorescent detection (CGE–LIF) to analyze the released nucleic acids.
The success of screening column and mobile phase combinations that generate dissimilar selectivity is highlighted in a typical method development strategy.
The incorporation of a post-column reaction using a 3D-printed, two-stage microreactor is showing groundbreaking performance improvements for flame ionization detection in many gas chromatography applications—and delivers carbon universal response.
The authors describe a method of reductive chlorination that enables the determination of total PCB content by gas chromatography with flame ionization detection.
There are many benefits of using high-resolution mass spectrometry (HRMS) in analyzing PFAS accumulating in living organisms. This article shows how HRMS, when combined with exposure-relevant mixtures, can help elucidate more about PFAS toxicity and exposure.
High-resolution mass spectrometry (HRMS) is an increasingly critical tool for identifying, characterizing, and monitoring attributes of protein-based therapeutics.
Online SPE–LC–MS/MS combined with the method presented enabled automated cleanup of food extracts and determination of PFAS compounds in the ng/kg range.
The advantages provided by the implementation of ion mobility spectrometry (IMS), and in particular travelling wave ion mobility spectrometry (TWIMS), in traditional liquid chromatography–mass spectrometry (LC–MS) systems are discussed.
The article discusses the classification and characterization of GC×GC column sets based on polarity and orthogonality, introducing a standardized approach using a reference mixture called the Century Mix to evaluate the selectivity and performance of these column sets.
Analysis of the compositional variation in living cells is essential for understanding biological processes. Single-cell elemental analysis by triple-quadrupole ICP-MS is emerging as a selective, highly sensitive, and potentially high-throughput technique for the study of constitutive elements, and uptake of metallodrugs (or metal-containing nanomaterials) in single cells.
As 2D-LC becomes used more widely and in regulated laboratory environments, development and implementation of SSTs will be critical for successful routine use of the 2D-LC technique.
Analyzing representative standard mixtures, APIs, and synthetic impurities shows that when TRLC is combined with RPLC in 2D-LC, separation performance is improved. We explain why.
Non-targeted analysis of small molecules with ambient ionization mass spectrometry (AI-MS) is enabled by new mass spectral libraries and algorithms, such as the inverted library search algorithm (ILSA) developed at NIST.
An overview of different approaches for the qualitative and quantitative analysis of polysorbates.