A novel mass spectrometric method for formaldehyde in children's personal-care products and water via derivatization with acetylacetone

Simple and fast microderivatization method for determining formaldehyde using narrow-bore liquid chromatography with UV detection

Formaldehyde is a harmful substance that can cause sick building syndrome and other diseases, such as contact allergy, asthma, leukemia, cancer, and brain/neuron disorders. Formaldehyde is a ubiquitous chemical owing to its use in many common products, including as a preservative in household and personal care products. To prevent overexposure to formaldehyde, a simple method for determining and controlling the formaldehyde content in commercial products is required. In this study, 3-aminoquinoline (3-AQ) was used to derivatize formaldehyde under mild conditions (2 min at 30 °C) without the use of catalysts or activators. The derivatized sample solutions were separated using narrow-bore liquid chromatography with an ultraviolet (UV) detector in a run time of only 5 min. All sample extraction and derivatization protocols were performed on the microliter scale to reduce the use of organic solvents. The linear range for the determination was 5-1000 μg mL-1, with a detection limit of approximately 1 μg mL-1 (2 ng per 2 μL injection). The proposed microscale method was successfully applied to the analysis of formaldehyde in commercial household products.

Applications of mass spectrometry in cosmetic analysis: An overview

Mass spectrometry (MS) is a crucial tool in cosmetic analysis. It is widely used for ingredient screening, quality control, risk monitoring, authenticity verification, and efficacy evaluation. However, due to the diversity of cosmetic products and the rapid development of MS-based analytical methods, the relevant literature needs a more systematic collation of information on this subject to unravel the true potential of MS in cosmetic analysis. Herein, an overview of the role of MS in cosmetic analysis over the past two decades is presented. The currently used sample preparation methods, ionization techniques, and types of mass analyzers are demonstrated in detail. In addition, a brief perspective on the future development of MS for cosmetic analysis is provided.

Reactivity of Formaldehyde during 4-Hydroxy-2-butanone Synthesis in Supercritical State

4-Hydroxy-2-butanone, an important intermediate for vitamin A and fragrances, is usually produced by aldol condensation of acetone and formaldehyde. Noncatalytic synthesis of 4-hydroxy-2-butanone in supercritical state, which was fast and had high production yield, was widely applied. Previous research on 4-hydroxy-2-butanone synthesis in the supercritical state focused on the formation and dehydration of 4-hydroxy-2-butanone while ignoring side reactions involving formaldehyde, which were studied in this paper. A reaction pathway of 4-hydroxy-2-butanone supercritical synthesis containing formaldehyde side reactions was proposed. The cross-disproportionation of formaldehyde and formic acid was found to be the main consumption of formic acid. The effects of initial formaldehyde and formic acid mass fractions in the feed on side reactions were studied. Based on the experiments conducted from 523.15 K to 563.15 K and 17 MPa, a kinetic model was suggested. The relative deviations between experimental and simulated data were less than 10%.

Progress and Challenges in Quantifying Carbonyl-Metabolomic Phenomes with LC-MS/MS

Carbonyl-containing metabolites widely exist in biological samples and have important physiological functions. Thus, accurate and sensitive quantitative analysis of carbonyl-containing metabolites is crucial to provide insight into metabolic pathways as well as disease mechanisms. Although reversed phase liquid chromatography electrospray ionization mass spectrometry (RPLC-ESI-MS) is widely used due to the powerful separation capability of RPLC and high specificity and sensitivity of MS, but it is often challenging to directly analyze carbonyl-containing metabolites using RPLC-ESI-MS due to the poor ionization efficiency of neutral carbonyl groups in ESI. Modification of carbonyl-containing metabolites by a chemical derivatization strategy can overcome the obstacle of sensitivity; however, it is insufficient to achieve accurate quantification due to instrument drift and matrix effects. The emergence of stable isotope-coded derivatization (ICD) provides a good solution to the problems encountered above. Thus, LC-MS methods that utilize ICD have been applied in metabolomics including quantitative targeted analysis and untargeted profiling analysis. In addition, ICD makes multiplex or multichannel submetabolome analysis possible, which not only reduces instrument running time but also avoids the variation of MS response. In this review, representative derivatization reagents and typical applications in absolute quantification and submetabolome profiling are discussed to highlight the superiority of the ICD strategy for detection of carbonyl-containing metabolites.

Simple click chemistry-based derivatization to quantify endogenous formaldehyde in milk using ultra-high-performance liquid chromatography/tandem mass spectrometry in selected reaction monitoring mode

RATIONALE

Formaldehyde (FA) exposure via environmental pollution or through the food chain poses a serious threat to human health, especially in developing countries like India. Although the addition of FA to food is proscribed, it is often illegally added to foods such as milk to increase the shelf-life. There are challenges in differentiating the endogenous FA content in milk from externally added FA.

METHOD

We have developed a simple method using ultra-high-performance liquid chromatography/tandem mass spectrometry in selected reaction monitoring mode (UHPLC/MS/SRM) for the absolute quantification of endogenous FA in milk. The steps include fat removal, protein precipitation using acid, and spiking with labelled FA (FA*), followed by simple click chemistry-based derivatization using Girard P reagent (GP) and final analysis.

RESULTS

A standard curve with FA* was constructed and used for the calculation of endogenous FA in milk. The optimal conditions for the derivatization reaction using 500 μL of milk were: GP, 50 μg; temperature, 37°C; time, 60 min; and 0.1% HCl. The validation parameters such as accuracy (95.84 to 99.73%), precision (2.84 to 8.02%) and spiked recovery (>95%) are within the FDA guidelines. This method is highly sensitive [limit of detection (LOD) of 1 ng/mL] with a dynamic range of 3.12 to 200 ng/mL. The endogenous FA level in pasteurized cow milk is 70 ng/mL (n = 60). The FA content in raw milk samples from cow, goat and buffalo (each n = 10) varied from 134 to 255 ng/mL.

CONCLUSIONS

This method is precise and sufficiently sensitive to quantify endogenous FA in milk samples using a minimal sample volume. As it involves simple sample preparation steps, it can be used routinely to quantify endogenous FA.

TP-FRET-Based Fluorescent Sensor for Ratiometric Detection of Formaldehyde in Real Food Samples, Living Cells, Tissues, and Zebrafish

Formaldehyde (FA, HCHO) is a highly reactive carbonyl species, which is very harmful to humans and the environment as a tissue fixative and preservative. Therefore, developing some highly sensitive, selective, and rapid detection methods is significant for human health in food safety and environmental protection. Herein, a two-photon (TP) ratiometric sensor, CmNp-CHO, has been constructed by conjugating a TP donor (Π-push-pull-structure) with a FA off-on acceptor (functioned with hydrazide moiety) via a nonconjugated linker through the fluorescence resonance energy transfer mechanism. Such a scaffold affords CmNp-CHO a reliable and specific probe for detecting FA with two well-resolved emission peaks separated by 124 nm. Also, it responds to FA rapidly with high selectivity and sensitivity during 1.0 min and a large ratio enhancement at I₅₅₀/I₄₂₆ with addition of 0-20μM FA, exhibiting ∼4-fold ratio increase and a fairly low LOD of 8.3 ± 0.3 nM. Moreover, CmNp-CHO has been successfully employed for detecting FA in live cells, onion tissues, and zebrafish, exhibiting that CmNp-CHO can serve as a useful tool for investigating FA in real food application and offering strong theoretical support and technical means for investigation of physiological and pathological functions of FA.