RESUMO
Bacterial spores in materials and equipment pose significant biosecurity risks, making effective disinfection crucial. This study evaluated Ortho-phthalaldehyde (OPA) and a quaternary ammonia-glutaraldehyde solution (AG) for inactivating spores of Bacillus thuringiensis (BT), B. cereus (BC), and two strains of B. velezensis (BV1 and BV2). Spores of BV1 and BT were treated with 22.5 mg/m3 OPA by dry fumigation or 1 mg/mL AG by spray for 20 min, according to the manufacturer's recommendation. As no sporicidal effect was observed, OPA was tested at 112.5 mg/m3 for 40 min, showing effectiveness for BT but not for BV1. Minimum bactericidal concentration (MBC) tests revealed higher MBC values for glutaraldehyde, prompting an overnight test with 112.5 mg/m3 OPA by dry fumigation and 50 mg/mL AG by spray, using formaldehyde as a control. AG reduced all Bacillus strains, but with limited sporicidal effect. OPA was sporicidal for BT and BV1 but not for BC and BV2, indicating a strain-dependent effect. Formaldehyde performed better overall but did not completely inactivate BV2 spores. Our findings suggest that OPA and AG have potential as formaldehyde replacements in wet disinfection procedures.
Assuntos
Bacillus thuringiensis , Bacillus , Desinfetantes , Glutaral , Esporos Bacterianos , Desinfetantes/farmacologia , Esporos Bacterianos/efeitos dos fármacos , Bacillus/efeitos dos fármacos , Bacillus/fisiologia , Glutaral/farmacologia , Bacillus thuringiensis/efeitos dos fármacos , Bacillus thuringiensis/fisiologia , Testes de Sensibilidade Microbiana , o-Ftalaldeído/farmacologia , Bacillus cereus/efeitos dos fármacos , Viabilidade Microbiana/efeitos dos fármacos , Desinfecção/métodosRESUMO
Aspartame is an artificial sweetener used in drinks and many foods. International Agency for Research on Cancer classified aspartame as possibly carcinogenic to humans (IARC Group 2B). In this study, a sensitive and selective spectrofluorimetric method was developed to detect aspartame. The method is based on switching on the fluorescence activity of aspartame upon its condensation with O-phthalaldehyde (Roth's reaction) in the presence of 2-mercaptoethanol. The reaction product was detected fluorometrically at λem of 438 nm after λex of 340 nm. All reaction conditions required to yield the optimal fluorescence intensity were observed and investigated. Furthermore, the approach was validated according to ICH guidelines. Upon plotting the concentrations of aspartame against their associated fluorescence intensity values, the relationship between the two variables was linear within the range of 0.5-3.0 µg/mL. Furthermore, the method was employed to analyze the quantity of aspartame in commercial packages and soft drinks with an acceptable level of recovery. In addition, the Green Solvents Selecting Tool, Complementary Green Analytical Procedure Index, and the Analytical Greenness Metric tool were used to evaluate the sustainability and the greenness of the developed methodology.
Assuntos
Aspartame , Bebidas Gaseificadas , Espectrometria de Fluorescência , Edulcorantes , Comprimidos , Aspartame/análise , Edulcorantes/análise , Espectrometria de Fluorescência/métodos , Comprimidos/análise , Bebidas Gaseificadas/análise , o-Ftalaldeído/química , Química Verde , Mercaptoetanol/químicaRESUMO
Glutathione has long been considered a key biomarker for determining the antioxidant response of the cell. Hence, it is a primary marker for reactive oxygen species studies. The method utilizes Ortho-phthalaldehyde (OPA) to quantify the cellular concentration of glutathione(s). OPA conjugates with reduced glutathione (GSH) via sulfhydryl binding to subsequently form an isoindole, resulting in a highly fluorescent conjugate. To attain an accurate result of both oxidized glutathione (GSSG) and GSH, a combination of masking agents and reducing agents, which have been implemented in this protocol, are required. Treatments may also impact cellular viability. Hence, normalization via protein assay is presented in this multiparametric assay. The assay demonstrates a pseudo-linear detection range of 0.234 - 30µM (R2=0.9932±0.007 (N=12)) specific to GSH. The proposed assay also allows for the determination of oxidized glutathione with the addition of the masking agent N-ethylmaleimide to bind reduced glutathione, and the reducing agent tris(2-carboxyethyl) phosphine is introduced to cleave the disulfide bond in GSSG to produce two molecules of GSH. The assay is used in combination with a validated bicinchoninic acid assay for protein quantification and an adenylate kinase assay for cytotoxicity assessment.
Assuntos
Glutationa , Oxirredução , o-Ftalaldeído , o-Ftalaldeído/química , Glutationa/análise , Glutationa/química , Glutationa/metabolismo , Humanos , Animais , Dissulfeto de Glutationa/análise , Dissulfeto de Glutationa/metabolismo , Dissulfeto de Glutationa/química , Fosfinas/químicaRESUMO
OBJECTIVES: The American Conference of Governmental Industrial Hygienists recommends a threshold limit value-ceiling (TLV-C) of 0.1 ppb for occupational exposure to ortho-phthalaldehyde (OPA) used in washing endoscope probes. To adhere to this extremely low exposure limit, this case study aimed to reduce OPA exposure concentrations of workers during immersion washing of an endoscope probe body. This was achieved by attaching a new duct and hood to the existing ceiling exhaust system. METHODS: The type of hood was determined by calculating and comparing the capture velocity obtained by assuming either an exterior or an enclosing hood. Additionally, the effect on improving the working environment was tested before and after the installation of the hood by measuring the OPA vapor concentration. RESULTS: The calculated capture velocities of the exterior and enclosing hoods were 0.05 m/s and 0.19 m/s, respectively. Considering the operability, the exterior hood was more appropriate; however, the calculated capture velocity indicated potential inadequacy in meeting the TLV-C requirement, leading to the adoption of the enclosing hood. The OPA vapor concentration in ceiling value measurements taken after the enclosing hood was fitted was reduced to 0.2 ppb, that is, 1/10 of the original concentration. CONCLUSIONS: Although the environmental concentration after the improvement still exceeded the TLV-C of 0.1 ppb, this study's findings indicate that even substances with extremely low occupational exposure limits can be managed with appropriate local exhaust ventilation.
Assuntos
Poluentes Ocupacionais do Ar , Exposição Ocupacional , Ventilação , o-Ftalaldeído , Exposição Ocupacional/análise , Exposição Ocupacional/prevenção & controle , Humanos , Poluentes Ocupacionais do Ar/análise , Níveis Máximos Permitidos , Desenho de EquipamentoRESUMO
Herein, a new, direct paper-based fluorimetric method is described for the quantitative determination of glutathione (GSH) molecules in nutritional supplements. Briefly, the proposed analytical method is based on the fluorescence emission resulting from the direct and selective chemical reaction of GSH molecules with the derivatization reagent that is o-phthalaldehyde (OPA) in acidic conditions at room temperature. The intensity of the emitted fluorescence on the surface of the analytical paper devices after irradiation with a lamp at 365 nm is proportional to the concentration of GSH and is measured using a smartphone as the detector. This methodology, which is suitable for measurements in laboratories with limited resources, does not require specialized instrumentation or trained personnel. The protocol governing the proposed method is simple and easily applicable. Essentially, the chemical analyst should adjust the value of pH on the surface of the paper by adding a minimal amount of buffer solution; then, after adding a few microliters of the derivatization reagent, wait for the surface of the paper to dry and, finally, add the analyte. Subsequently, the irradiation of the sensor and the measurement of the emitted fluorescence can be recorded with a mobile phone. In the present study, several parameters affecting the chemical reaction and the emitted fluorescence were optimized, the effect of interfering compounds that may be present in dietary supplements was examined, and the stability of these paper sensors under different storage conditions was evaluated. Additionally, the chemical stability of these paper devices in various maintenance conditions was studied, with satisfactory results. The detection limit calculated as 3.3 S/N was 20.5 µmol L-1, while the precision of the method was satisfactory, ranging from 3.1% (intra-day) to 7.3% (inter-day). Finally, the method was successfully applied to three different samples of dietary supplements.
Assuntos
Suplementos Nutricionais , Fluorometria , Glutationa , Papel , o-Ftalaldeído , o-Ftalaldeído/química , Suplementos Nutricionais/análise , Fluorometria/métodos , Glutationa/análise , Glutationa/química , Espectrometria de Fluorescência/métodosRESUMO
Gizzerosine [2-amino-9-(4-imidazolyl)-7-azanonanoic acid] is a toxic amino acid formed from histamine and lysine at high temperatures, and may be present in foodstuffs (e.g., fishmeal and meat-bone meal) for animals including cats and dogs. Here we developed a simple, rapid, sensitive, specific, and automated method for the analysis of gizzerosine in foodstuffs by high-performance liquid chromatography (HPLC) involving pre-column derivatization with o-phthaldialdehyde (OPA) in the presence of N-acetylcysteine (instead of the usual 2-mercaptoethanol or ethanethiol reagent). OPA reacted immediately (within 1 min) with gizzerosine in an autosampler at room temperatures (e.g., 20-25 °C), and their derivative was directly injected into the HPLC column. The highly fluorescent gizzerosine-OPA derivative was well separated from the OPA derivatives of all natural amino acids known to be present in physiological fluids (e.g., plasma), proteins and foodstuffs, and was detected at an excitation wavelength of 340 nm and an emission wavelength of 450 nm. The total time for chromatographic separation (including column regeneration) was 20 min per sample rather than 40 min and longer in previous HPLC methods. The detection limit for gizzerosine was at least 6 pmol/ml in an assay solution (HPLC vial) or at least 0.09 pmol per injection into the HPLC column. The analysis of gizzerosine was linear between 1 and 100 pmol per injection. When gizzerosine was extracted from foodstuffs, its detection limit was at least 875 pmol/g foodstuff or at least 0.21 mg/kg foodstuff. Our routine HPLC technique does not require any cleanup of samples or the OPA derivatization products (including the OPA-gizzerosine adduct), and is applicable for the analysis of gizzerosine in both foodstuffs and animal tissues.
Assuntos
Imidazóis , o-Ftalaldeído , Animais , Gatos , Cães , Cromatografia Líquida de Alta Pressão , Histamina , AminoácidosRESUMO
In the pharmaceutical industry, effective risk management and control strategies for potential genotoxic impurities are of paramount importance. The current study utilized GC-MS to evaluate a precise, linear, and accurate analytical method for quantifying ethylenediamine present in tripelennamine hydrochloride using phthalaldehyde as a derivatizing agent. When phthalaldehyde is sonicated for 10 min at room temperature, it reacts with ethylenediamine to form (1z,5z)-3,4-dihydrobenzo[f][1,4]diazocine. This approach minimizes matrix interference issues and resolves sample preparation difficulties encountered during ethylenediamine identification in GC-MS. In this method, helium serves as the carrier gas, while methanol acts as the diluent. The stationary phase consists of a DB-5MS column (30 m × 0.25 mm × 0.25 µm) with a flow rate of 1.5 mL/min. The retention time of (1z,5z)-3,4-dihydrobenzo[f][1,4]diazocine was determined to be 6.215 min. The method validation demonstrated limits of detection and quantification for (1z,5z)-3,4-dihydrobenzo[f][1,4]diazocine at 0.4 and 1.0 ppm, respectively, with a linearity range spanning from 1 to 30 ppm concentration with respect to the specification level. System suitability, precision, linearity, and accuracy of the current method were assessed in accordance with guidelines, yielding results deemed suitable for the intended use.
Assuntos
Contaminação de Medicamentos , Etilenodiaminas , Cromatografia Gasosa-Espectrometria de Massas , Limite de Detecção , o-Ftalaldeído , Cromatografia Gasosa-Espectrometria de Massas/métodos , Etilenodiaminas/química , Reprodutibilidade dos Testes , o-Ftalaldeído/química , Modelos LinearesRESUMO
Flavipin, a fungal lower molecular weight biomolecule (MW 196.16 g/mol), has not been yet extensively studied for beneficial preclinical and clinical applications. In recent years, various preclinical mouse models including adjuvant-induced arthritis (AIA) were employed to understand mechanisms associated with Rheumatoid arthritis (RA) and to develop new therapeutic drugs. In the current study, we studied the inhibitory effect of Flavipin on major signaling molecules involved in the inflammatory response during RA using both in-silico virtual interaction and in vivo mouse model of AIA. Our in-silico results clarified that Flavipin interacts with the tumor necrosis factor alpha (TNF-α) through conventional hydrogen binding (H-H) at one of TNF-α critical amino acids tyrosine residues, Tyr119, with binding energy (b.e.) -5.9. In addition, Flavipin binds to ATP-binging sites of the Jesus kinases, JAK1, JAK2 and JAK3, through H-H (b. e. between -5.8 and -6.1) and then it may inhibit JAKs, regulators of RA signaling molecules. Moreover, our molecular dynamics stimulation for the docked TNF-α/Flavipin complex confirmed the specificity and the stability of the interaction. In vitro, Flavipin is not toxic to normal cells at doses below 50 µM (its IC50 in normal fibroblast cell line was above 100 µM). However, in vivo, the arthritis score and hind paw oedema parameters were modulated in Flavipin treated mice. Consistent with the in-silico results the levels of the TNF-α, the nuclear transcription factor kappaB (NF-κB) and the signal transduction and activator of transcription (STAT3, downstream of JAKs) were modulated at joint tissues of the hind-paw of Flavipin/AIA treated mice. Our data suggest Flavipin as a potential therapeutic agent for arthritis can inhibit RA major signaling molecules.
Assuntos
Artrite Experimental , Artrite Reumatoide , o-Ftalaldeído/análogos & derivados , Camundongos , Animais , Fator de Necrose Tumoral alfa/farmacologia , Transdução de Sinais , Artrite Reumatoide/metabolismo , NF-kappa B/metabolismo , Fungos/metabolismo , Artrite Experimental/metabolismoRESUMO
Polysaccharide-based vaccines cannot stimulate long-lasting immune response in infants due to their inability to elicit a T-cell-dependent immune response. This has been addressed using conjugation technology, where conjugates were produced by coupling a carrier protein to polysaccharides using different conjugation chemistries, such as cyanylation, reductive amination, ethylene diamine reaction, and others. Many glycoconjugate vaccines that are manufactured using different conjugation technologies are already in the market for neonates, infants and young children (e.g., Haemophilus influenzae type-b, Streptococcus pneumoniae and Neisseria meningitidis vaccines), and all of them elicit a T-cell dependent immune response. To manufacture glycoconjugate vaccines, the capsular polysaccharide is first activated by converting its hydroxyl groups to aldehyde-, cyanyl-, or cyanate ester groups, depending on the conjugation chemistry selected. The oxidized and reduced aldehyde functional groups of the polysaccharides are subsequently reacted with the amino groups of carrier protein by reductive amination to form a stable amide bond. In CDAP-based conjugation, the polysaccharide -OH groups are activated to form cyanyl-, or cyanate ester groups to react with the amino groups of carrier protein and forms an isourea bond. Understanding the extent of polysaccharide activation/modification is essential since it directly influences the molar mass of the conjugate, its stability, and the immunogenicity of the product. Reported methods are available to estimate the aldehyde groups of polysaccharides generated by reductive amination. However, no method is available to quantify the cyanyl or cyanate ester (-OCN) groups generated by cyanylation with 1-cyano-4-dimethylaminopyridinium tetrafluoroborate (CDAP). We report a novel strategy using an O-phthalaldehyde (OPA) derivatization process followed by size-exclusion chromatography (SEC) high-performance liquid chromatography (HPLC) separation and UV detection. The cyanate ester groups on the activated polysaccharide directly reveal the extent of polysaccharide activation/modification and the residual activated groups in the purified conjugates. This method would be useful for conjugate vaccine manufacturing using CDAP chemistry.
Assuntos
Polissacarídeos Bacterianos , o-Ftalaldeído , Lactente , Criança , Recém-Nascido , Humanos , Pré-Escolar , Vacinas Conjugadas/química , Proteínas de Transporte , Glicoconjugados , Cianatos , Ésteres , Anticorpos AntibacterianosRESUMO
Herein, a step-by-step protocol for simultaneous detection of 20 amino acids commonly present in cell culture media is described. The protocol facilitates detection of both primary and secondary amino acids through a two-step precolumn derivatization strategy using ortho-phthalaldehyde and 9-fluorenylmethyl chloroformate as derivatizing agents. The separation of derivatized amino acids with varying hydrophobicity is achieved through reverse-phase chromatography. The amino acids are simultaneously detected in a single workflow through the use of Variable Wavelength Detector at 338 and 262 nm. The protocol is applicable for both mammalian and bacterial cell culture matrices with an option for automation of precolumn derivatization.
Assuntos
Aminoácidos , Produtos Biológicos , Animais , Cromatografia Líquida de Alta Pressão/métodos , Aminoácidos/química , o-Ftalaldeído/química , Aminas , MamíferosRESUMO
Homotaurine (HOM) is considered a promising drug for the treatment of Alzheimer's and other neurodegenerative diseases. In the present work, a new high-performance liquid chromatography with fluorescence detection (HPLC-FLD) (λex. = 340 nm and λem. = 455 nm) method was developed and validated for the study of substance permeability in the central nervous system (CNS). Analysis was performed on a RP-C18 column with a binary gradient elution system consisting of methanol-potassium phosphate buffer solution (pH = 7.0, 0.02 M) as mobile phase. Samples of homotaurine and histidine (internal standard) were initially derivatized with ortho-phthalaldehyde (OPA) (0.01 M), N-acetylcysteine (0.01 M) and borate buffer (pH = 10.5; 0.05 M). To ensure the stability and efficiency of the reaction, the presence of different nucleophilic reagents, namely (a) 2-mercaptoethanol (2-ME), (b) N-acetylcysteine (NAC), (c) tiopronin (Thiola), (d) 3-mercaptopropionic acid (3-MPA) and (e) captopril, was investigated. The method was validated (R2 = 0.9999, intra-day repeatability %RSD < 3.22%, inter-day precision %RSD = 1.83%, limits of detection 5.75 ng/mL and limits of quantification 17.43 ng/mL, recovery of five different concentrations 99.75-101.58%) and successfully applied to investigate the in vitro permeability of homotaurine using Franz diffusion cells. The apparent permeability (Papp) of HOM was compared with that of memantine, which is considered a potential therapeutic drug for various CNSs. Our study demonstrates that homotaurine exhibits superior permeability through the simulated blood-brain barrier compared to memantine, offering promising insights for enhanced drug delivery strategies targeting neurological conditions.
Assuntos
Acetilcisteína , Memantina , Acetilcisteína/química , Cromatografia Líquida de Alta Pressão/métodos , o-Ftalaldeído/química , Indicadores e Reagentes , Tiopronina , Reprodutibilidade dos TestesRESUMO
A high-throughput fluorimetric assay for histidine was developed, using a 96-well plates platform. The analyte reacts selectively with o-phthalaldehyde under mild alkaline conditions to form a stable derivative. Instrumental-free detection was carried out using a smartphone after illumination under UV light (365 nm). The method was proved to be linear up to 100 µM histidine, with an LLOQ (lower limit of quantification) of 10 µM. The assay was only prone to interference from glutathione and histamine that exist in the urine samples at levels that are orders of magnitude lower compared to histidine. Human urine samples were analyzed following minimum treatment and were found to contain histidine in the range of 280 to 1540 µM. The results were in good agreement with an HPLC corroborative method.
Assuntos
Ensaios de Triagem em Larga Escala , Histidina , Smartphone , Fluorometria/métodos , Histidina/urina , Humanos , o-Ftalaldeído/químicaRESUMO
A new automated, generic analytical approach for determining the clinical disinfectant o-phthalaldehyde (OPA) is reported in this study. The proposed sequential injection analysis (SIA) is based on the online reaction of the OPA with glycine/N-acetylcysteine (NAC) in a neutral medium (pH = 7.0) to form a highly fluorescent isoindole derivative. All critical flow and reaction variables were investigated, while validation was carried out in the linearity detection range (0.0075-0.02%). As a result, excellent linearity (R2 > 0.99) and precision (1.5-2.4% for repeatability and 0.7-2.2% for reproducibility) were achieved for the reference OPA solutions. Furthermore, reasonable concentration verification of OPA disinfection (0.2-0.6%) in healthcare institutes can be achieved using the developed fluorescent SIA due to its good sensitivity (0.111 V/%) and precision (1.0-2.3% for intermediate precision) around the minimum effective concentration (MEC) of 0.3% for Cidex-OPA disinfectant.
Assuntos
Desinfetantes , o-Ftalaldeído , o-Ftalaldeído/análise , Reprodutibilidade dos Testes , Glutaral , CorantesRESUMO
Injectable antibacterial hydrogels have attracted considerable attention in wound management. However, the development of injectable hydrogels with excellent antibacterial activity, good biocompatibility, and strong tissue adhesion remains a challenge. In this study, an antibacterial tissue-adhesive hydrogel was developed based on a catalyst-free o-phthalaldehyde (OPA)/amine reaction by simply mixing OPA-terminated four-arm poly(ethylene glycol) (4aPEG-OPA) and ε-poly-l-lysine (ε-PLL) solutions. The hydrogel showed tunable gelation time, storage moduli, and degradation rate depending on the polymer concentration and 4aPEG-OPA/ε-PLL mass ratio. The hydrogel exhibited nearly 100% bacterial inhibition rates in-vitro against Gram-negative E. coli and Gram-positive S. aureus, while maintaining good biocompatibility. The hydrogel matched well in shape and tightly adhered to the tissue after in-situ formation at the wound sites. Following the treatment of rat models of full-thickness skin incisions and round wounds, the hydrogel effectively closed the wounds and promoted wound healing. Moreover, after administering to S. aureus infected full-thickness skin wounds, the hydrogel exhibited remarkable efficacy in inhibiting wound infection with a bacterial inhibition rate over 99.94%, achieving a significantly accelerated wound healing compared with the commercially available Prontosan® gel. Therefore, the hydrogel exhibits great potential as a wound dressing for infection prevention and promotion of healing.
Assuntos
Adesivos Teciduais , Infecção dos Ferimentos , Ratos , Animais , Hidrogéis/farmacologia , o-Ftalaldeído/farmacologia , Adesivos Teciduais/farmacologia , Escherichia coli , Staphylococcus aureus , Bactérias , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Infecção dos Ferimentos/tratamento farmacológicoRESUMO
OBJECTIVE: To compare the effectiveness of disinfection protocols utilizing a ultraviolet (UV) Smart D60 light system with Impelux™ technology with a standard Cidex ortho-phthalaldehyde (OPA) disinfection protocol for cleaning flexible fiberoptic laryngoscopes (FFLs). METHODS: Two hundred FFLs were tested for bacterial contamination after routine use, and another 200 FFLs were tested after disinfection with one of four methods: enzymatic detergent plus Cidex OPA (standard), enzymatic detergent plus UV Smart D60, microfiber cloth plus UV Smart D60, and nonsterile wipe plus UV Smart D60. Pre- and post-disinfection microbial burden levels and positive culture rates were compared using Kruskal-Wallis ANOVA and Fisher's two-sided exact, respectively. RESULTS: After routine use, approximately 56% (112/200) of FFLs were contaminated, with an average contamination level of 9,973.7 ± 70,136.3 CFU/mL. The standard reprocessing method showed no positive cultures. The enzymatic plus UV, microfiber plus UV, and nonsterile wipe plus UV methods yielded contamination rates of 4% (2/50), 6% (3/50), and 12% (6/50), respectively, with no significant differences among the treatment groups (p > 0.05). The pre-disinfection microbial burden levels decreased significantly after each disinfection technique (p < 0.001). The average microbial burden recovered after enzymatic plus UV, microfiber plus UV, and nonsterile wipe plus UV were 0.40 CFU/mL ± 2, 0.60 CFU/mL ± 2.4, and 12.2 CFU/mL ± 69.5, respectively, with no significant difference among the treatment groups (p > 0.05). Micrococcus species (53.8%) were most frequently isolated, and no high-concern organisms were recovered. CONCLUSION: Disinfection protocols utilizing UV Smart D60 were as effective as the standard chemical disinfection protocol using Cidex OPA. LEVEL OF EVIDENCE: NA Laryngoscope, 133:3512-3519, 2023.
Assuntos
Laringoscópios , Humanos , Laringoscópios/microbiologia , Glutaral , Detergentes , Desinfecção/métodos , o-Ftalaldeído , Contaminação de Equipamentos/prevenção & controleRESUMO
Ortho-phthalaldehyde (OPA) is used as a high-level disinfectant for reusable medical devices in healthcare settings. The ACGIH recently adopted a Threshold Limit Value-Surface Limit (TLV-SL; 25 µg/100 cm2) for OPA surface contamination to prevent induction of dermal and respiratory sensitization following dermal exposure. However, there is no current validated method to measure OPA surface contamination. This study aimed to develop a standardized approach for sample collection and quantitative determination of OPA from work surfaces for use in risk assessment practices. The reported method utilises readily available commercial wipes to collect surface samples coupled with direct detection of OPA via liquid chromatography time of flight mass spectrometry (LC-ToF-MS). This approach avoided complex derivatization steps commonly required for the analysis of aldehydes. Method evaluation was conducted in accordance with the Occupational Safety and Health Administration (OSHA) surface sampling guidelines. Overall recoveries of 25 µg/100 cm2 of OPA from stainless steel and glass surfaces were 70% and 72%, respectively. The reported LOD for this method was 1.1 µg/sample and the LOQ was 3.7 µg/sample. OPA remained stable on the sampling medium for up to 10 days, when stored at 4 °C. The method was demonstrated in a workplace surface assessment at a local hospital sterilising unit, successfully detecting OPA on work surfaces. This method is intended to supplement airborne exposure assessment and provide a quantitative assessment tool for potential dermal exposure. When used in conjunction with a thorough occupational hygiene program that includes hazard communication, engineering controls, and personal protective equipment, skin exposure and consequent sensitization risks in the workplace can be minimized.
Assuntos
Desinfetantes , Exposição Ocupacional , Estados Unidos , Humanos , o-Ftalaldeído/análise , Exposição Ocupacional/análise , Desinfetantes/análise , Aldeídos , Espectrometria de MassasRESUMO
In the present study, naphthalene-2,3-dicarboxaldehyde (NDA) was used in on-line post column derivatization (PCD) coupled to liquid chromatography under the new concept of Pulsed-PCD. In Pulsed-PCD, the reagents are introduced into the flowing stream of the mobile phase under precise timing overlapping the eluted analyte. The consumption of the reagents is minimized to a few microliters, resulting in a significant advantage, that is the use of expensive reagents in PCD. For this reason, NDA-CN chemistry was used for the determination of histamine in food samples, such as eggplant and spinach. Two additional methods were developed based on the reaction of histamine with o-phthalaldehyde (OPA), namely the classic OPA - nucleophilic compound reaction and the specific OPA - histamine reaction in alkaline medium. The chromatographic conditions and the Pulsed-PCD conditions were investigated, while the analytical figures of merit were satisfactory. In all three methods, a pulse of 50 µL was used (OPA/NDA + Buffer), reducing dramatically the consumption of PCD reagents.
Assuntos
Histamina , o-Ftalaldeído , Histamina/análise , o-Ftalaldeído/química , Indicadores e Reagentes , Cromatografia Líquida de Alta Pressão/métodosRESUMO
The study proposes an o-phthalaldehyde (OPA) sensor for rapid and reliable detection of OPA in healthcare disinfection practices, based on a hydrogel-modified screen-printed carbon electrode strip. The hydrogel film, which contains glycine and N-acetylcysteine, reacts with OPA to produce a reductive isoindole derivative. The derivative is then oxidized for OPA determination using cyclic voltammetry. The proposed sensor achieves an optimal detection time of 20-30 s and requires only a small analyte volume of 5 µL. It exhibits good precision (10%) and sensitivity (3.3 µA/cm2 mM) in a phosphate-buffered solution (pH 7.6), with excellent linearity (R2 > 0.97) and precision (<3%) in the detection range (0.2-0.6%) required for clinical OPA solutions. Moreover, the sensor demonstrates good concentration verification of Cidex-OPA disinfection in healthcare institutes, with high sensitivity (18.28 µA/cm2 mM) and precision around the minimum effective concentration (0.3%). Overall, the proposed sensor offers a promising and practical solution for accurate and reliable OPA detection in clinical disinfection practices.
Assuntos
Desinfetantes , o-Ftalaldeído , Hidrogéis , Técnicas Eletroquímicas , EletrodosRESUMO
BACKGROUND: Prevention of spread of Streptococcus equi subspecies equi (S. equi) after an outbreak is best accomplished by endoscopic lavage of the guttural pouch, with samples tested by culture and real time, quantitative polymerase chain reaction (qPCR). Disinfection of endoscopes must eliminate bacteria and DNA to avoid false diagnosis of carrier horses of S. equi. HYPOTHESIS/OBJECTIVES: Compare failure rates of disinfection of endoscopes contaminated with S. equi using 2 disinfectants (accelerated hydrogen peroxide [AHP] or ortho-phthalaldehyde [OPA]). The null hypothesis was that there would be no difference between the AHP and OPA products (based on culture and qPCR results) after disinfection. METHODS: Endoscopes contaminated with S. equi were disinfected using AHP, OPA or water (control). Samples were collected before and after disinfection and submitted for detection of S. equi by culture and qPCR. Using a multivariable logistic regression model-adjusted probability, with endoscope and day as controlled variables, the probability of an endoscope being qPCR-positive was determined. RESULTS: After disinfection, all endoscopes were culture-negative (0%). However, the raw unadjusted qPCR data were positive for 33% AHP, 73% OPA, and 71% control samples. The model-adjusted probability of being qPCR-positive after AHP disinfection was lower (0.31; 95% confidence interval [CI], -0.03-0.64) compared to OPA (0.81; 95% CI, 0.55-1.06), and control (0.72; 95% CI, 0.41-1.04). CONCLUSION AND CLINICAL IMPORTANCE: Disinfection using the AHP product resulted in significantly lower probability of endoscopes being qPCR-positive compared to the OPA product and control.
Assuntos
Desinfetantes , Streptococcus equi , Animais , Cavalos , Desinfetantes/farmacologia , Desinfecção/métodos , Endoscópios/microbiologia , o-Ftalaldeído , Peróxido de Hidrogênio/farmacologiaRESUMO
Dipeptidyl peptidase-4 enzyme suppressant is a unique category of oral antidiabetic medication. Sitagliptin (STG) is a perfect member of this category and is pharmaceutically marketed alone or in combination with metformin. Here, the ideal application of an isoindole derivative for STG assay was developed using a feasible, easy-to-use, economic, and affordable method. STG as an amino group donor can form a luminescent derivative: isoindole on interaction with o-phthalaldehyde and the existence of (2-mercaptoethanol) 0.02% (v/v) as a thiol group donor. Excitation (339.7 nm) and emission (434.6 nm) wavelengths were used to monitor the isoindole fluorophore yield; moreover, each experimental variable was carefully investigated and adjusted. The calibration graph was constructed by plotting fluorescence intensities against STG concentrations, and controlled linearity was observed at concentrations ranging from 50 to 1000 ng/ml. The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use guidelines were analyzed in depth to prove the technique validation. The implementation of the present technique was extended successfully to the evaluation of various types of STG dose forms and spiking samples of human plasma and urine. The developed technique was shown to be an effective, simple, and quick replacement for quality control and clinical study evaluation of STG.