Determination of formaldehyde in single cell by capillary electrophoresis with LIF detection

A sensitive fluorometric-colorimetric dual-mode intelligent sensing platform for the detection of formaldehyde

Excess formaldehyde (FA) is a strong carcinogen, so the development of a rapid visualized and portable formaldehyde detection platform is of great research importance. A multi-color fluorescence sensing system constituted of model compound (NAHN) and red-emitting InP/ZnS QDs was constructed herein, which can simultaneously realize fluorometric-colorimetric dual-mode sensing when exposed to FA environment. Its preparation process was simplified, the detection process was green, and the limits of detection (LOD) were 0.623 μM and 0.791 μM, respectively. The high recoveries of FA in actual water samples indicated that the sensor had broad application prospects. The prepared fluorescent film can be utilized for rapid visual simulation analysis of FA on the surface of various fruits and vegetables. In addition, a serial logic gate was designed to quickly semi-quantitatively assess FA concentration, which promoted the realization of on-site intelligent evaluation of FA.

Novel Method of Analysis for the Determination of Residual Formaldehyde by High-Performance Liquid Chromatography

Formaldehyde is commonly used as an alkylating agent in the pharmaceutical industry. Consequently, its residual level in drug substances and/or their intermediates needs to be accurately quantified. Formaldehyde is a small, volatile molecule with a weak chromophore (the carbonyl group), and its direct analysis by GC-FID and HPLC-UV is difficult. For these reasons, the majority of papers found in the literature are based upon a derivatisation process (most commonly using the desensitised explosive 2,4-dinitrophenylhydrazine) prior to the analysis of formaldehyde. A novel high-performance liquid chromatography (HPLC) method with UV detection for its quantification in a pharmaceutical is described in this paper. The method proposed herein is based upon a derivatisation reaction between formaldehyde and 4-methylbenzenesulfonohydrazide (MBSH) before analysis by HPLC-UV. Selectivity, linearity, limit of quantification, accuracy, repeatability, intermediate precision, and solution stability were successfully assessed as per ICH guideline Q2(R1), and the method has also been validated in a good manufacturing practice (GMP) laboratory in the UK.

A benzothiazole-based ratiometric fluorescent probe for detection of formaldehyde and its applications for bioimaging

We presented a new benzothiazole-based fluorescent probe for ratiometric sensing of formaldehyde. Upon treatment with formaldehyde, the alkylamine-functionalized probe can be converted to its aldehyde analogue via the target-mediated 2-aza-Cope rearrangement, which led to significant shifts in both absorption (from 392 to 452 nm) and emission (from 492 to 552 nm) bands. The sensing mechanism was confirmed by HPLC, UV/Vis and fluorescence spectroscopy. The probe is capable of sensing formaldehyde under physiological conditions with high selectivity over potentially competing biological analytes. The probe also displayed sensitive ratiometric fluorescence response (up to 35.7 fold) for formaldehyde with a low limit detection of 0.58 μM. Furthermore, the probe was successfully employed for ratiometric imaging of formaldehyde in living cells as well as in zebrafish.