Approaches to Formaldehyde Measurement: From Liquid Biological Samples to Cells and Organisms

The Importance of Tracking "Missing" Metabolites: How and Why?

Technologies currently employed to find and identify drug metabolites in complex biological matrices generally yield results that offer a comprehensive picture of the drug metabolite profile. However, drug metabolites can be missed or are captured only late in the drug development process. This could be due to a variety of factors, such as metabolism that results in partial loss of the molecule, covalent bonding to macromolecules, the drug being metabolized in specific human tissues, or poor ionization in a mass spectrometer. These scenarios often draw a great deal of attention from chemistry, safety assessment, and pharmacology. This review will summarize scenarios of missing metabolites, why they are missing, and associated uncovering strategies from deeper investigations. Uncovering previously missed metabolites can have ramifications in drug development with toxicological and pharmacological consequences, and knowledge of these can help in the design of new drugs.

Negative formaldehyde release from textiles washed with a formaldehyde-containing laundry soap according to manufacturer instructions: An application of chromotropic acid testing

BACKGROUND

Formaldehyde is a common preservative used to prevent microbial growth in water. It can be found in personal care products and household cleaning products, including laundry detergents. Formaldehyde has frequently been recognised as a cause of allergic contact dermatitis, but whether it remains present in textiles washed with formaldehyde-containing laundry detergents is unknown.

OBJECTIVES

This study aimed to utilise the chromotropic acid method (CAM) to assess formaldehyde release from textiles washed with a laundry detergent known to contain formaldehyde.

MATERIALS AND METHODS

Textiles were laundered with a detergent containing calcium formate at four concentrations (0×, 0.5×, 1× and 5× the recommended amount per manufacturer label) and kept wet or allowed to dry. Select textiles were subjected to an additional rinse cycle. Textiles were then tested utilising the CAM. A sample of the pure laundry detergent was also tested using the CAM.

RESULTS

The CAM was positive only for wet textiles washed at 5× the recommended concentration of detergent and pure detergent. All dry textiles were negative.

CONCLUSIONS

Formaldehyde release was not detected from any textiles washed following the manufacturer's recommendations. Once dry, it is likely safe for formaldehyde-allergic patients to wear textiles washed with formaldehyde-containing detergents.

Quantitative detection of formaldehyde using solid phase microextraction gas chromatography-mass spectrometry coupled to cysteamine scavenging

Formaldehyde (HCHO) is a toxic and carcinogenic pollutant and human metabolite that reacts with biomolecules under physiological conditions. Quantifying HCHO is essential for ongoing biological and biomedical research on HCHO; however, its reactivity, small size and volatility make this challenging. Here, we report a novel HCHO detection/quantification method that couples cysteamine-mediated HCHO scavenging with SPME GC-MS analysis. Our NMR studies confirm cysteamine as an efficient and selective HCHO scavenger that out-competes O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine, the most commonly used scavenger, and forms a stable thiazolidine amenable to GC-MS quantification. Validation of our GC-MS method using FDA and EMA guidelines revealed detection and quantification limits in the nanomolar and micromolar ranges respectively, while analysis of bacterial cell lysate confirmed its applicability in biological samples. Overall, our studies confirm that cysteamine scavenging coupled to SPME GC-MS analysis provides a sensitive and chemically robust method to quantify HCHO in biological samples.

Reversible Near-Infrared Fluorescent Probe for Rapid Sensing Sulfur Dioxide and Formaldehyde: Recognition and Photoactivation Mechanism and Applications in Bioimaging and Encryption Ink

A novel near-infrared (NIR) fluorescent Probe 1 was successfully developed for the reversible detection of sulfur dioxide derivatives and formaldehyde. The purple solution of Probe 1 faded to colorless in 1.8 s with the addition of HSO₃^-. Meanwhile, its fluorescence signal disappeared instantaneously with a 39 nM detection limit. The probe exhibited excellent selectivity toward HSO₃^- over other potential interfering agents. Then, its absorption and fluorescence bands were able to effectively recover in response to formaldehyde. Remarkably, this reverse process was able to accelerate 84 times under UV light in 122 s and achieved a recovery rate of 98% by UV light, the photoactivation mechanism was fully determined by HRMS and theoretical calculation. Furthermore, we demonstrated that Probe 1 was successfully applied for the detection of sulfur dioxide derivatives and formaldehyde in living cells and data encryption.