Derivatization Step Research Articles

Alternative Method for Glyphosate Determination in Unroasted Green Coffee Beans by Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS).

This research proposes an alternative method to detect and quantify glyphosate residues in unroasted green coffee beans by LC-MS/MS. The sample preparation was conducted without derivatization steps, with integrated cleanup, which improves the analytical method's frequency. Validation results were consistent with the requirements of the regulatory guidelines employed. Specificity, linearity (r2 = 0.9991), precision (RSD ≤ 9%), and recovery (92-112%) were ensured, with a satisfactory limit of quantification (LOQ = 0.48 mg kg-1). These data demonstrate that the method is suitable for monitoring glyphosate residues in unroasted coffee beans while offering simplicity and speed in sample preparation. The method was applied to analyze authentic unroasted coffee bean samples, in which two of them were contaminated with glyphosate (<LOQ). These results exhibit the importance of glyphosate monitoring in coffee samples and enhance that the method can be successfully implemented as a tool to guarantee food quality and safety.

Quantification of Epoxyeicosatrienoic acids Enantiomers: The development of reliable and practical liquid chromatography mass Spectrometry assay

Epoxyeicosatrienoic acids (EETs) are increasingly recognized as key metabolites in the arachidonic acid (AA) metabolic pathway. EETs are epoxy derivatives of AA with two chiral centers formed by cytochrome P450 (CYP) enzymes. EETs have reported biological activities as racemates; however, knowledge on specific optical isomers of EET is lacking. A main reason is the absence of practical assay to quantify EETs isomers associated with specific pathological conditions and enzymes. The reported underivatized chiral LC-MS/MS assays utilize different mobile phases and flow rates or required long run times to achieve separation of EET stereoisomers. Others incorporated a derivatization step before the separation of EETs in their assays. Therefore, the objective of this study was to develop and validate a stereoselective assay for the simultaneous quantitation of underivatized EET enantiomers using Liquid Chromatography Mass Spectrometry (LC-MS/MS) with an optimum baseline separation using binary mobile phase and gradient elution. Herein, we report the development and validation of an LC-MS/MS assay, and its application to quantify the formation of EET enantiomers mediated by human liver microsomes. Assay linearity extends over 10–600 ng/mL with r2 > 0.99 for all EETs enantiomers. The inter-run accuracy was within ± 15 %, and precision was ≤ 15 %, and < 20 % for the LLOQ. The matrix effect for the current assay was within ≤ ±20 %, and the mean recovery for quantitative methods was 70–125 %. The assay proved to be reliable and practical for chiral analysis.

Regarding Bioanalysis Lasting a Few Minutes: Automated Cooling-SPME and Fast-GC for Urinary 2-Phenyl-2-Propanol Monitoring.

An innovative SPME head space GC-MS method, in cooling mode, using a fully automated routine, was developed to detect 2-phenyl-2-propanol, a representative urinary metabolite of cumene. Following an acid hydrolysis and derivatization step with lowered quantities of reagents, acetic anhydride and pyridine, a 30 μm polydimethylsiloxane SPME fiber was used to sample derivatized 2-phenyl-2-propanol, such as benzenemethanol,α,α-dimethyl-acetate, from the headspace. Performances of the method, optimized through experimental design, provide an LOD of 0.034 mg/L and an LOQ 0.10 mg/L, with a short sampling time necessary per sample. The method, developed on standard solutions, will be applied to both occupationally exposed and non-exposed populations.

One-pot derivatization/magnetic solid-phase extraction combined with high-performance liquid chromatography-fluorescence detection for rapid analysis of biogenic amines in alcoholic beverages

The determination of biogenic amines (BAs) in alcoholic beverages is crucial for assessing their health impact, ensuring beverage quality, and guaranteeing safety. Herein, a rapid one-pot derivatization/magnetic solid-phase extraction (OPD/MSPE) method was proposed using 6-aminoquinolinyl-N-hydroxysuccinimide carbamate as the derivatization reagent and magnetic hydroxyl-functionalized multi-walled carbon nanotubes as the extraction material. Integration of derivatization and extraction steps simplifies the sample preparation process, taking only three minutes and eliminating the need for centrifugation by utilizing magnetic sorbent. The resulting desorption solution was directly analyzed by high-performance liquid chromatography-fluorescence detection (HPLC-FLD) without any evaporation or reconstitution steps. The integrated OPD/MSPE-HPLC-FLD method demonstrates excellent linearity (R2 > 0.992), accuracy (relative recoveries: 85.1–109.2%), precision (RSDs≤9.7%) and detection limits (limits of detection: 0.3–2 ng/mL). It has been successfully applied to determine free BAs in various alcoholic beverages, including red wine, Baijiu, Huangjiu, and beer. This method enables rapid, sensitive and precise analysis of BAs in alcoholic beverages.

Efficient derivatization-free monitoring of glycosyltransferase reactions via flow injection analysis-mass spectrometry for rapid sugar analytics

The widespread application of enzymes in industrial chemical synthesis requires efficient process control to maintain high yields and purity. Flow injection analysis-electrospray ionization-mass spectrometry (FIA-ESI–MS) offers a promising solution for real-time monitoring of these enzymatic processes, particularly when handling challenging compounds like sugars and glycans, which are difficult to quickly analyze using liquid chromatography-mass spectrometry due to their physical properties or the requirement for a derivatization step beforehand. This study compares the performance of FIA-MS with traditional hydrophilic interaction liquid chromatography (HILIC)-ultra high-performance liquid chromatography (UHPLC)-mass spectrometry (MS) setups for the monitoring of the enzymatic synthesis of N-acetyllactosamine (LacNAc) using beta-1,4-galactosyltransferase. Our results show that FIA-MS, without prior chromatographic separation or derivatization, can quickly generate accurate mass spectrometric data within minutes, contrasting with the lengthy separations required by LC–MS methods. The rapid data acquisition of FIA-MS enables effective real-time monitoring and adjustment of the enzymatic reactions. Furthermore, by eliminating the derivatization step, this method offers the possibility of being directly coupled to a continuously operated reactor, thus providing a rapid on-line methodology for glycan synthesis as well.Graphical

Development of a capillary electrophoresis method with laser-induced fluorescence detection for the characterization of oligosaccharides in human milk

Breast milk is the most appropriate food for an infant in the first months of life - it provides the essential nutrients required for proper growth, with breast milk oligosaccharides (HMOs) being the third most abundant component. HMO concentrations vary based on factors like lactation stage and maternal health. They play crucial roles in infant health, acting as prebiotics, antimicrobials, and immune modulators. Analytical methods like capillary electrophoresis and liquid chromatography are the most often used in HMOs qualitative and quantitative analysis. Continuing research aims to enhance analytical techniques for comprehensive HMOs analysis, this work presents the development of a capillary electrophoresis method with laser-induced fluorescence detection along with derivatization and solid-phase extraction steps for the characterisation of major oligosaccharides in colostrum samples. Validation parameters, such as linearity (0.9949–0.9989), limits of detection (5.49–16.40 ng cm−3) and quantification (18.30–54.67 ng cm−3), intra- and inter-day precision (2.41–9.78% and 1.27—14.5%, respectively), trueness (− 8.4 to − 2.0%), and recovery (70.02–113.5%) and repeatability (2.22–10.58%) for solid-phase extraction stage were assessed. The method was evaluated using RGB additive colour model regarding the analytical and practical effectiveness and greenness of the method (achieving a brilliance score of 67.1%). Moreover, the developed method was successfully applied to determine three oligosaccharides (DSLNT, 3’SL, and 6’SL) in colostrum samples. Considering its effectiveness, the method has promise for this type of application.Graphical abstract

Determination of capsaicin at trace levels in different food, biological and environmental samples by quadruple isotope dilution-gas chromatography mass spectrometry after its preconcentration

Despite the therapeutic properties of capsaicin for some diseases, it shows some side effects for human health. The goal of this study was to develop a precise and accurate analytical strategy for the trace determination of capsaicin in different food, biological and environmental samples including pepper, saliva and wastewater by gas chromatography–mass spectrometry (GC–MS) after spraying-based fine droplet formation-liquid phase microextraction (SFDF-LPME) and quadruple isotope dilution (ID4) method. Acetic anhydride was used as derivatizing agent, and the extraction method was used to enrich the analyte derivative to reach low detection limits. Under the optimum conditions, limit of detection (LOD) and limit of quantitation (LOQ) were determined to be 0.33 and 1.10 µg/kg, respectively. Percent recoveries calculated for SFDF-LPME-GC-MS method ranged between 84.1 and 131.7 %. After the application of ID4-SFDF-LPME-GC-MS method, percent recoveries were obtained in the range of 94.9 and 104.0 % (%RSD ≤ 2.8) for the selected samples. It is obvious that the isotope dilution-based method provided high accurate and precise results due to the elimination of errors during the derivatization, extraction and measurement steps.

In Migratio Noncovalent Fluorophore Labeling of Proteins by Propidium Iodide in Sodium Dodecyl Sulfate Capillary Gel Electrophoresis.

Sodium dodecyl sulfate capillary gel electrophoresis is one of the frequently used methods for size-based protein separation in molecular biology laboratories and the biopharmaceutical industry. To increase throughput, quite a few multicapillary electrophoresis systems have been recently developed, but most of them only support fluorescence detection, requiring fluorophore labeling of the sample proteins. To avoid the time-consuming derivatization reaction, we developed an on-column labeling approach utilizing propidium iodide for the first time in SDS-CGE of proteins, a dye only used before for nucleic acid analysis. As a key ingredient of the gel-buffer system, the oppositely migrating positively charged propidium ligand in migratio complexes with the SDS-proteins, therefore, supports in situ labeling during the electrophoretic separation process, not requiring any extra pre- or postcolumn derivatization step. A theoretical treatment is given to shed light on the basic principles of this novel online labeling process, also addressing the influence of propidium iodide on the electroosmotic flow, resulting in reduced retardation. The concept of propidium labeling in SDS-CGE was first demonstrated using a commercially available protein sizing ladder ranging from 6.5 to 200 kDa with different isoelectric points and post-translational modifications. Considering the increasing number of protein therapeutics on the market next, we focused on the labeling optimization of a therapeutic monoclonal antibody and its subunits, including the addition of the nonglycosylated heavy chain. Peak efficiency and resolution were compared between noncovalent and covalent labeling. The effect of ligand concentration on the effective and apparent electrophoretic mobility, the resulting peak area, and the resolution were all evaluated in view of the theoretical considerations. The best detection sensitivity for the intact monoclonal antibody was obtained by using 200 μg/mL propidium iodide in the separation medium (LOD 2 μg/mL, 1.35 × 10-8 M) with excellent detection linearity over 3 orders of magnitude. On the other hand, the resolution between the biopharmaceutical protein test mixture components containing the intact and subunit fragments of the therapeutic monoclonal antibody was very good in the ligand concentration range of 50-200 μg/mL, but using the local maximum at 100 μg/mL for the nonglycosylated/glycosylated heavy chain pair is recommended. The figures of merit, including precision, sensitivity, detection linear range, and resolution for a sample mixture in hand, can be optimized by varying the propidium iodide concentration in the gel-buffer system, as demonstrated in this paper.

Solid‐contact ion‐selective sensor for the direct determination of procyclidine HCl and application of in‐line dissolution profiling of its tablets

AbstractThe ability to obtain accurate analytical results without sample pre‐treatment or derivatization is a key element for an eco‐friendly method of analysis. In this work, green electro analytical method was developed and evaluated for the selective determination of the anti‐cholinergic drug Procyclidine Hydrochloride in both pure and dosage forms as well as in dissolution medium without sample pre‐treatment. Firstly, screening of four ionophore‐doped polyvinyl chloride‐based membranes were conducted to detect the one with highest affinity towards the studied drug. Accordingly, calix[4]arene‐doped membrane exhibited the optimum results. Then optimization was carried out by designing screen‐printed and glassy carbon solid‐contact ion‐selective electrodes with multiwall carbon nanotube and graphene nanocomposite as ion to electron transducers. The fabricated screen‐printed sensor with graphene nanocomposite was characterized according to IUPAC recommendations. It acquired the fastest and most stable response, along with thermal stability up to 30 °C. It also displayed a slope of 43.9±0.2 mV/decade in a pH range of 2–5. The proposed sensor successfully obtained a linear range of 1×10−5–1×10−2 M and the theoretical limit of detection was 6.3×10−6 M. Finally, it was used in applications such as in‐line dissolution monitoring and quantification of procyclidine in its dosage form without prior sample pre‐treatment or derivatization steps. Furthermore, the graphene nanocomposite transducer has been imaged by Scanning Electron Microscope (SEM).

Low-field NMR spectroscopic study of e-cigarettes: Is determination of only nicotine and organic carrier solvents possible?

Electronic cigarettes (e-cigarettes) have become popular worldwide with the market growing exponentially in some countries. The absence of product standards and safety regulations requires urgent development of analytical methodologies for the holistic control of the growing diversity of such products. An approach based on low-field nuclear magnetic resonance (LF-NMR) at 80 MHz is presented for the simultaneous determination of key parameters: carrier solvents (vegetable glycerine (VG), propylene glycol (PG) and water), total nicotine as well as free-base nicotine fraction. Moreover, qualitative and quantitative determination of fourteen weak organic acids deliberately added to enhance sensory characteristics of e-cigarettes was possible. In most cases these parameters can be rapidly and conveniently determined without using any sample manipulation such as dilution, extraction or derivatization steps. The method was applied for 37 authentic e-cigarettes samples. In particular, eight different organic acids with the content up to 56 mg/mL were detected. Due to its simplicity, the method can be used in routine regulatory control as well as to study release behaviour of nicotine and other e-cigarettes constituents in different products.

A validated reverse-phase LC-MS/MS method for the analysis of haloacetic acids in drinking water: supporting the transition from HAA5 to HAA9

ABSTRACT Haloacetic acids (HAAs) are potentially toxic by-products formed from interactions between organic matter and chlorine during disinfection of drinking water, with brominated HAAs forming when bromide is present. Some countries require monitoring of drinking water for five HAAs, but there is increasing health concern related to the more toxic brominated HAAs and monitoring of nine HAAs (HAA9) is becoming more widespread. However, existing methods of analysis for HAA9 are often sub-optimal, involving complex derivatisation steps and/or long analytical run times. This article presents an improved methodology utilising reverse-phase liquid chromatography mass spectrometry (LC-MS/MS) for which sample preparation involves simple pH adjustment and the analytical run takes 10 min. The efficacy of the method was demonstrated by a full validation across four drinking water matrices with good sensitivity (&amp;lt;0.8 μg/L), precision (&amp;lt;7%), and bias (&amp;lt;10%) observed. A direct comparison using real water samples was performed against the widely used existing gas chromatography method. The new LC-MS/MS method was significantly quicker and easier and demonstrated improved performance in terms of accuracy and precision. This has implications for understanding the risk posed by HAAs in chlorinated water by eliminating the possible historical under-estimates of the levels of the more toxic brominated compounds.

Simultaneous determination of eight organic amines in desulfurization solution by ion chromatography

The applications of organic-amine desulfurization have steadily increased owing to its high efficiency, low cost, and low energy consumption. Different proportions of organic amines exert different effects on sulfur dioxide removal. Therefore, the accurate determination of different organic amines in the desulfurization solution is of great importance. The ion-chromatographic method for the detection of organic amines does not require a derivatization step, has simple pretreatment procedures, and allows for the simultaneous determination of many types of organic amines. In this study, a method based on ion chromatography was developed for the simultaneous determination of ethanolamine (MEA), diethylethanolamine (DEEA), n-methyldiethanolamine (MDEA), 2-amino-2-methyl-1-propanol (AMP), hydroxyethylethylenediamine (AEEA), piperazine (PZ), n-hydroxyethylpiperazine (HEPZ), and diethylenetriamine (DETA). The separation efficiency of the eight organic amines in different types of columns, leaching solutions, and column temperatures were compared. The determination was performed using an IonPac CS17 column with column temperature of 35 ℃ and gradient leaching with methyl sulfonic acid (MSA) solution via the inhibition conductance method. Samples of the desulfurization solution were analyzed using ultrapure water filtered through a 0.22 μm nylon microporous filter membrane and an OnGuard Ⅱ RP column; thus, the pretreatment steps are simple. The eight organic amines showed a good linear relationship within a certain concentration range, and the coefficient of determinations (R2) were greater than 0.998. The limits of detection (LODs) and quantification (LOQs) were determined from the mass concentrations of the organic amines corresponding to signal-to-noise ratios (S/N) of 3 and 10, respectively. LODs of 0.02-0.08 mg/L and LOQs of 0.07-0.27 mg/L were determined from a 1.0 μL sample injection. The actual recoveries ranged from 93.0% to 111%, and the relative standard deviations (RSDs, n=5) ranged from 0.31% to 1.2%. The results indicated that the proposed method has good accuracy and precision; thus, it is suitable for the determination of various organic amines in desulfurization solution.

Structural characterization of fatty acid anions via gas-phase charge inversion using Mg(tri-butyl-terpyridine)2 2+ reagent ions.

Free fatty acids and lipid classes containing fatty acid esters are major components of lipidome. In the absence of a chemical derivatization step, FA anions do not yield all of the structural information that may be of interest under commonly used collision-induced dissociation (CID) conditions. A line of work that avoids condensed-phase derivatization takes advantage of gas-phase ion/ion chemistry to charge invert FA anions to an ion type that provides the structural information of interest using conventional CID. This work was motivated by the potential for significant improvement in overall efficiency for obtaining FA chain structural information. A hybrid triple quadrupole/linear ion-trap tandem mass spectrometer that has been modified to enable the execution of ion/ion reaction experiments was used to evaluate the use of 4,4',4″-tri-tert-butyl-2,2':6',2″-terpyridine (ttb-Terpy) as the ligand in divalent magnesium complexes for charge inversion of FA anions. Mg(ttb-Terpy)2 2+ complexes provide significantly improved efficiency in producing structurally informative products from FA ions relative to Mg(Terpy)2 2+ complexes, as demonstrated for straight-chain FAs, branched-chain FAs, unsaturated FAs, and cyclopropane-containing FAs. It was discovered that most of the structurally informative fragmentation from [FA-H + Mg(ttb-Terpy)]+ results from the loss of a methyl radical from the ligand followed by radical-directed dissociation (RDD), which stands in contrast to the charge-remote fragmentation (CRF) believed to be operative with the [FA-H + Mg(Terpy)]+ ions. This work demonstrates that a large fraction of product ions from the CID of ions of the form [FA-H + Mg(ttb-Terpy)]+ are derived from RDD of the FA backbone, with a very minor fraction arising from structurally uninformative dissociation channels. This ligand provides an alternative to previously used ligands for the structural characterization of FAs via CRF.

Chiral analysis of amphetamine, methamphetamine, MDMA and MDA enantiomers in human hair samples.

A novel analytical method was developed for the simultaneous quantification of the R/S-enantiomers of amphetamine, methamphetamine, MDA and MDMA in hair samples using liquid chromatography-tandem mass spectrometry (LC-MS-MS). This method involved a straightforward derivatization step with dansyl chloride and the use of a chiral column, enabling the separation and quantification of all eight enantiomers in a single analysis. The method exhibited excellent linearity across a concentration range of 0.03-3.00 ng/mg for each enantiomer. Precision and accuracy were within acceptable limits, with bias and relative standard deviation (RSD) values consistently below 6% and 9%, respectively. Selectivity and specificity assessments confirmed the absence of any interference from contaminants or co-extracted drugs. The method demonstrated high sensitivity, with limits of detection (LOD) below 8 pg/mg and limits of quantification (LOQ) below 19 pg/mg for all analytes. Extraction recovery exceeded 79%, and matrix effects were minimal for all analytes. Processed sample stability evaluations revealed consistent results with deviations below 11% for all analytes. Application of the method to 32 authentic human hair samples provided valuable insights into amphetamine use patterns, allowing differentiation between medical amphetamine consumption and illicit use based on enantiomeric composition. Additionally, the method detected co-use of methamphetamine, MDA or MDMA in some samples, highlighting its applicability in drug monitoring and real-life case scenarios within a forensic institute. This innovative analytical approach offers a sensitive and selective method for enantiomeric differentiation of amphetamine, methamphetamine, MDA and MDMA in human hair samples, providing a valuable tool for forensic and clinical investigations.

Simultaneous Determination of D and L Enantiomers of 2-Hydroxyglutarate by UHPLC-MS/MS Method in Human Biological Fluids and its Clinical Application.

2-hydroxyglutarate has limited abundance in normal tissues but a high level under certain pathologic conditions. To clarify the diagnostic value of two chiral isomers of 2-hydroxyglutarate in plasma and urine of Chinese cancer patients, an ultra-high performance liquid chromatography-tandem mass spectrometric method was developed for simultaneous quantification of D-/L-2-hydroxyglutarate. The selected D-/L-2-hydroxyglutarate-d5 as internal standards were added to samples before the SPE on Waters Oasis® MAX 96-Well plate (30μm, 60mg). A derivatization step with (+)-O,O'-diacetyl-L-tartaric anhydride permitted the chromatography separation of D-/L-2-hydroxyglutarate on an ACQUITY UPLC-HSS T3 column (50 × 2.1mm, i.d. 1.8μm) with acetonitrile and water (containing 0.1% formic acid and 10mmol ammonium acetate) as the mobile phase. The calibration curves showed good linearity (R ≥ 0.99) over the concentration ranges of 200-5,000ng/mL and 500-20,000ng/mL for analysis of D-/L-2-hydroxyglutarate in plasma and urine samples, respectively. Intra- and inter-run precision were ≤ 12.33%, and the accuracy was within the range of -10.44 to 13.90%. This method was further successfully applied to clinical sample analysis in isocitrate dehydrogenase 1/2 mutated Chinese cancer patients.

Kinetics and Thermodynamics of Lactose Mutarotation through Chromatography.

The mutarotation kinetics and thermodynamics of the reaction α-lactose ⇌ β-lactose have been measured in dilute solutions using liquid chromatography without any derivatization step, using a C18 column and pure water as the mobile phase. The effect of temperature (0.5-45 °C) of the starting powder composition (α-lactose-rich or β-lactose-rich powder) and of the solvent composition (water with up to 35% weight fraction of seven organic solvents) has been experimentally investigated. Increasing the temperature leads to faster kinetics, following an Arrhenius model, and to slightly decreasing concentration-based equilibrium ratio. Conversely, increasing the weight fraction of organic solvent at 25 °C resulted in slower kinetics and smaller concentration-based equilibrium ratio. The starting powder composition is shown not to influence the kinetics or thermodynamics of the process. The corresponding parameter estimation problem is thoroughly discussed, taking into account the small difference in response factors of the lactose diastereomers.

Development and validation of a UPLC-PDA method for simultaneous nitrate and nitrite determination in vegetable, fruit and meat-based baby foods

With a notable rise in the consumption of commercial baby foods in recent years, there is a pressing need for a rapid and efficient method to analyze the levels of nitrate and nitrite in these products. In the present study, we have successfully developed, validated, and applied a UPLC-PDA method for the quantification of nitrate and nitrite in various samples. This method involves an extraction procedure, followed by a straightforward derivatization step using sulfanilamide for nitrite determination. After derivatization, nitrate was directly quantified based on its corresponding peak, and nitrite was determined through its derivative response. The validation process demonstrated good linearity and specificity over a range of 25–400 mg/kg, along with satisfactory precision, accuracy, and excellent recoveries. Furthermore, the detection and quantification limits were found to be very satisfactory. The effectiveness of the method was confirmed through the analysis of various matrices, showcasing its rapidity, and reliability.

Calibration of a passive sampling device for the determination of nitrogen dioxide in ambient air

Nitrogen dioxide (NO2), a common air pollutant, has been widely admitted to be harmful to both the environment and human health, demanding its well-control procedure and corresponding quantification. In this study, NO2 in ambient air was collected by a passive sampling method using the Willems badge diffusive sampler, followed by a derivatization step with the Griess-Saltzman solution, and analyzed by ultraviolet-visible (UV–vis) spectroscopy at 543 nm. The device can be utilized for 168 h of continuous field sampling. The experimental sampling rate (Ke) of (4.02 ± 0.29) × 10−3 m3h−1 with a relative standard deviation (% RSD) of 9.6 % was determined by conducting parallel experiments between an active sampling method (ISO 6768:1998) and the Willems samplers. After exposure time, samplers could be stored for two weeks in a refrigerator at 4 °C before analyzing. The studied passive diffusive sampler was simple, low-cost, easy to reuse; permitted determining the average concentration of NO2 in ambient air. The average NO2 concentrations for 2-hour to 4-hour sampling periods at different studied sampling sites in Ho Chi Minh city (Vietnam) were ranged from 11.5 to 189 μg m−3.

Determination of nitrofuran metabolites in muscle by LC-MS/MS and LC-MS/MS/MS: Alternative validation according to Commission Implementing Regulation (EU) 2021/808

Nitrofurans are banned in food of animal origin in the European Union. A rugged liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) and LC-MS/MS cubed (LC-MS/MS/MS) analytical method allowing the confirmation of five metabolites of nitrofuran antibacterial agents, furaltadone, furazolidone, nifursol, nitrofurantoin and nitrofurazone in animal muscle tissue was developed and validated. The validation of 1-aminohydantoin (AHD), 3-amino-5-methyl-morpholino-2-oxazolidinone (AMOZ), 3-amino-2-oxazolidinone (AOZ), 3,5-dinitrosalicylic acid hydrazide (DNSH) and semicarbazide (SEM) was carried out according to Commission Implementing Regulation (EU) 2021/808, by the adoption of a matrix-comprehensive in-house validation concept and the standard addition calibration. Validation was successfully performed, starting from 0.4 µg kg−1. Decision limit (CCα), recovery, repeatability, within-laboratory reproducibility and uncertainty of measurement were determined together with a factorial effect analysis. The procedure was verified through the analysis of two certified reference materials. The sample preparation consisted in acid hydrolysis and derivatization steps, followed by a liquid-liquid extraction of the analytes with ethylacetate.

One-pot derivatization/magnetic solid-phase extraction coupled with liquid chromatography-fluorescence detection for the rapid determination of sulfonamide residues in honey

Consuming foods with excess sulfonamide residues threatens human health, underscoring the importance of their detection in food. This study presents an innovative one-pot derivatization/magnetic solid-phase extraction (OPD/MSPE) method for sulfonamides analysis. This approach integrates the derivatization and extraction steps into a single process. The sample solution, along with the derivatization reagent fluorescamine and the sorbent magnetic hydroxyl multi-walled carbon nanotubes, is mixed and vortexed for 3 min. This procedure simultaneously conducts derivatization and extraction, with easy phase separation using an external magnet. This streamlined sample preparation method is completed in only 5 min and, when combined with liquid chromatography-fluorescence detection (LC-FLD), demonstrates excellent linearity (R2 > 0.99) and satisfactory detection limits (0.004–0.04 ng/g) for the quantification of nine sulfonamides in honey samples. The proposed OPD/MSPE-LC-FLD method is distinguished by its simplicity, rapidity, high sensitivity, and specificity, making it an outstanding advancement in the field of food safety analysis.