Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 69
Filtrar
1.
Cancer Med ; 13(2): e6976, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38379327

RESUMO

BACKGROUND: International bodies recommend that melanoma risk assessment should be integrated into skin cancer care provision, but evidence to support implementation is lacking. AIM: To explore the acceptability and feasibility of implementing personalised melanoma risk assessment and tailored patient education and skin surveillance within routine clinical care. METHODS: This prospective qualitative implementation study was informed by the Theoretical Framework of Acceptability (TFA). Personalised, systematic melanoma risk assessment was implemented in the dermatology clinic at the Melanoma Institute Australia, Sydney, Australia February-May 2021. Pre- and post-implementation observations and semi-structured interviews with patients and staff were conducted (September 2020-March 2021). Observational notes and interview transcript data were analysed thematically using the TFA as a classifying framework. RESULTS: A total of 37 h of observations were made, and 29 patients and 12 clinic staff were interviewed. We found that the delivery of personalised melanoma risk estimates did not impact on patient flow through the clinic. Dermatologists reported that the personalised risk information enhanced their confidence in assessing patient risk and recommending tailored surveillance schedules. Most patients reported that the risk assessment and tailored information were a beneficial addition to their care. Among patients whose risk deviated from their expectations, some reported feeling worried, confused or mistrust in the risk information, including those at lower risk who were recommended to decrease surveillance frequency. CONCLUSIONS: It is feasible and acceptable to patients and clinic staff to calculate and deliver personalised melanoma risk information and tailored surveillance as part of routine clinical care within dermatology clinics.


Assuntos
Dermatologia , Melanoma , Neoplasias Cutâneas , Humanos , Melanoma/diagnóstico , Melanoma/epidemiologia , Estudos de Viabilidade , Estudos Prospectivos , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/epidemiologia , Medição de Risco
2.
J Chromatogr A ; 1316: 78-91, 2013 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-24120027

RESUMO

A new, rapid, selective and sensitive ultrahigh performance liquid chromatography with diode array detection coupled to electrospray ionization and quadrupole time-of-flight mass spectrometry (UHPLC-DAD-ESI-Q-ToF-MS) strategy using automatic and simultaneous acquisition of exact mass at high and low collision energy, MS(E), has been developed to obtain polyphenolic profile of apples, apple pomace and apple juice from Asturian cider apples in a single run injection of 22 min. MS(E) spectral data acquisition overcomes chromatographic co-elution problems, performing simultaneous collection of precursor ions as well as other ions produced as a result of their fragmentation, which allows resolving complex spectra from mixtures of precursor ions in an unsupervised way and eases their interpretation. Using this technique, 52 phenolic compounds of five different classes were readily characterized in these apple extracts in both positive and negative ionization modes. The spectral data for phenolic compounds obtained using this acquisition mode are comparable to those obtained by conventional LC-MS/MS as exemplified in this work. Among the 52 phenolic compounds identified in this work, 2 dihydrochalcones and 3 flavonols have been tentatively identified for the first time in apple products. Moreover, 2 flavanols, 4 dihydrochalcones, 9 hydroxycinnamic acids and 4 flavonols had not been previously reported in apple by ToF analysis to our knowledge.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Flavonoides/análise , Malus/química , Fenóis/análise , Extratos Vegetais/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Cromatografia Líquida de Alta Pressão/instrumentação , Flavonoides/química , Íons/análise , Íons/química , Fenóis/química , Sensibilidade e Especificidade
3.
Anal Chim Acta ; 771: 56-64, 2013 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-23522113

RESUMO

A chemometric method for the treatment of ion mobility coupled to mass spectrometry (IMS/MS) data is proposed as a complementary tool for obtaining experimental evidence for the study of MS fragmentations, which can provide a direct and automatable methodology for characterising ionic series and the hierarchy of all product ions of an MS spectrum. Two MS/MS with ion mobility experiments have been designed: in the first, the intrinsic mobility of each ion is estimated, and in the second experiment, distributions of the ionic intensity of product ions fragmented after IMS separations are recorded. These mobilograms are aligned using the coshift algorithm and mathematically fitted using Classical Least Squares (CLS) to determine the mobility contributions from their precursor ions. Despite some limitations when studying low intensity ions and ions with similar ion mobility, CLS fitting improves the usage of IMS coupled with accurate mass spectrometry as a complementary tool in the study of MS fragmentation mechanisms and more notably, it offers an automatable and efficient alternative to MS3 experiments.


Assuntos
Flavonoides/química , Glicosídeos/química , Informática/métodos , Espectrometria de Massas/métodos , Prótons
5.
Talanta ; 88: 303-10, 2012 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-22265503

RESUMO

The feasibility of using Fourier Transform Mid-Infrared Spectroscopy (FT-MIR) combined with Partial Least Squares Regression (PLS-R) for the determination of 12 anthocyanins (3-O-glucosides of delphinidin, cyanidin, petunidin, peonidin and malvidin, as well as acetic acid esters and p-coumaric acid esters of petunidin, peonidin and malvidin and caffeic acid ester of malvidin) and three sums (sum of non-acylated anthocyanins, sum of acetylated anthocyanins and sum of coumaroylated anthocyanins), in red wines has been tested. Reference values of anthocyanin concentrations by reverse-phase High Performance Liquid Chromatography with Diode Array Detection (HPLC-DAD) were used to calibrate the models. A Principal Component Analysis (PCA) was applied to these reference values and a differentiation of wine samples by wine type (young wines of 2005, young wines of 2004 and crianza and reserva wines) has been possible. A calibration model using PLS-R was built with 153 samples of Rioja wines and the prediction of the anthocyanin concentrations using this model was evaluated by internal and external validation sample sets. Most of the anthocyanins and their sums have been predicted with a Standard Error of Prediction (SEP) of 15-30% for young wines recently bottled. However, for young wines after one year of being bottled, and for crianza and reserva wines, these errors were unacceptable. The obtained results suggest that the model built for FT-IR instrument calibration is a useful tool for a quick determination of the anthocyanin content of young wines of the current vintage, but a careful robust external validated calibration of the technique is necessary in order to maintain the prediction errors within controlled limits.


Assuntos
Antocianinas/análise , Glucosídeos/análise , Vinho/análise , Acetatos/análise , Acetilação , Ácidos Cafeicos/química , Calibragem , Cromatografia Líquida de Alta Pressão , Ácidos Cumáricos/química , Ésteres/análise , Estudos de Viabilidade , Análise dos Mínimos Quadrados , Análise de Componente Principal , Valores de Referência , Espectroscopia de Infravermelho com Transformada de Fourier , Estudos de Validação como Assunto
6.
Meat Sci ; 86(3): 859-64, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20696532

RESUMO

Records of cattle slaughtered at two Chilean slaughterhouses (SLH1 and SLH2) were used to determine prevalence and risk factors for carcasses with bruises. Bruise prevalence amounted to 12.3% but differed between slaughterhouses (20.8% for SLH1 and 8.6% for SLH2 respectively). Bruise severity grade 1 (mild) was most frequently recorded. The type of the animal, source of animal, the level of fat cover and lairage time were associated with the presence of bruises. Older categories of animals and animals that pass through a market before being moved to the slaughterhouse are more prone to show bruises. The results also indicate that under the reported Chilean circumstances animals that have longer lairage times (over 12 h) have a significantly reduced risk for bruises, except for oxen. Presence of bruises is also significantly associated with increased carcass pH values.


Assuntos
Criação de Animais Domésticos , Contusões , Carne , Matadouros , Tecido Adiposo , Animais , Bovinos , Chile , Concentração de Íons de Hidrogênio , Prevalência , Fatores de Risco , Índice de Gravidade de Doença
7.
J Mass Spectrom ; 44(7): 1017-25, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19283783

RESUMO

Fifteen flavonoid O-diglycosides with different interglycosidic linkage isomery and glycosylation position have been studied in order to analyze their fragmentation patterns. Initial separation was carried out using high performance liquid chromatography with diode array detection (HPLC/DAD) coupled to an electrospray ionization (ESI) interface and a triple quadrupole mass spectrometer. Some useful differences in their MS spectra have been found and discussed. As it has already been reported, [Y*]+/[Y0]+ ratio for flavanones and [Y1]+/[Y0]+ ratio for other flavonoids is specific for each isomeric interglycosidic linkage. In this work it has also been observed that the abundance of these ions is dependent on the position of glycosylation. On the basis of these differences, systematic guidelines for our experimental conditions have been proposed for the differentiation of not only isomeric interglycosidic linkage but also glycosylation position using collision-induced dissociation MS/MS (CID-MS/MS) spectra in positive mode. These results have been successfully applied for the characterization of three diglycosyl flavonoids found in Citrus fruit juices and these conclusions have also been extrapolated for characterizing two triglycosides in the same fruits.


Assuntos
Bebidas/análise , Flavonoides/análise , Frutas/química , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida de Alta Pressão/métodos , Citrus/química , Flavanonas/análise , Glicosilação , Isomerismo , Quercetina/análise , Rutina/análise
8.
Rev. Méd. Clín. Condes ; 19(4): 323-329, sept. 2008. tab
Artigo em Espanhol | LILACS | ID: lil-504164

RESUMO

El Helicobacter pylori es una bacteria que ha revolucionado la Gastroenterología en los últimos 25 años. Hasta mediados de los 80 la úlcera péptica era considerada una enfermedad sicosomática asociada a una hiperacidez gástrica en el caso de la úlcera duodenal (UD), o a una alteración de la barrera mucosa en el caso de la úlcera gástrica. Al descubrirse su relación con esta bacteria la enfermedad ulcero-péptica pasó a ser una enfermedad infecciosa con un muy alto índice de curación, y una muy baja tasa de recurrencia, lo que era la regla hasta ese entonces. No en vano este notable descubrimiento les valió a dos científicos australianos obtener el Premio Nóbel de Medicina en 2005. Revisaremos aspectos generales de este germen, su asociación con diversas patologías gastro-duodenales, los métodos de estudio clínico y su tratamiento de erradicación.


The Gastroenteroly has been dramatically impacted in last 25 years by a bacterium named helicobacter pylori. Until the eighties, peptic ulcer was considered as a psychosomatic disease related to high gastric acidity in duodenal ulcer (DU) or an impaired gastric mucosa in gastric ulcer. The helicobacter pylori-peptic ulcer relationship has changed the way we consider this disease, now it is an infectious disease with very high rate of clinical resolution and no more recurrences one of its more characteristic features. This outstanding medical discovery has deserved in 2005 the Nobel Prize to the Australian scientific investigators who made possible this medical breakthrough. This is a review on this bacterium, the diseases associated to it, the diagnostic clinical tests and its treatment.


Assuntos
Humanos , Helicobacter pylori/patogenicidade , Infecções por Helicobacter/diagnóstico , Infecções por Helicobacter/patologia , Infecções por Helicobacter/terapia , Helicobacter pylori/isolamento & purificação , Neoplasias Gástricas/microbiologia , Úlcera Gástrica/microbiologia
10.
Arq. bras. med. vet. zootec ; 60(3): 663-666, jun. 2008.
Artigo em Inglês | LILACS | ID: lil-487912

RESUMO

The occurrence of Amphiorchis caborojoensis Fischthal & Acholonu 1976 and Carettacola stunkardi Martin & Bamberger 1952 in a young specimen of Hawksbill sea turtle Eretmochelys imbricata Linnaeus 1758 in Brazil was reported. Five A. caborojoensis trematodes were found in the small intestine (n=2) and liver (n=3), and two adult C. stunkardi specimens were collected from body wash. This is the first report of parasites of E. imbricata in Brazilian waters and Southwestern Atlantic Ocean and the second report of members of the Spirorchiidae family in that region. In addition, E. imbricata is a new host recorded for C. stunkardi.


Relata-se a ocorrência de Amphiorchis caborojoensis Fischthal & Acholonu 1976 e Carettacola stunkardi Martin e Bamberger 1952, em um exemplar juvenil de tartaruga marinha de pente Eretmochelys imbricata Linnaeus 1758 no Brasil. Foram coletados cinco trematódeos da espécie A. caborojoensis, dois no intestino delgado e três no fígado e dois exemplares adultos de C. stunkardi no lavado corporal. Destes apenas a espécie A. caborojoensis já tinha sido relatada como parasita dessa espécie de quelônio marinho. Esta é a primeira descrição de parasitas em E. imbricata em águas brasileiras e na área do Atlântico Sul Ocidental, e o segundo relato de membros da família Spirorchiidae na mesma região.


Assuntos
Animais , Doenças Parasitárias/epidemiologia , Helmintos/isolamento & purificação , Fauna Marinha , Tartarugas
12.
Neurology ; 70(15): 1244-9, 2008 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-18391156

RESUMO

OBJECTIVE: High-frequency subthalamic nucleus deep brain stimulation (STN-DBS) is an established treatment for patients with advanced Parkinson disease (PD). To date, intraoperative monitoring of parkinsonian symptoms, such as tremor and bradykinesia, is largely based on subjective strategies. We conducted a pilot study to evaluate short-term intraoperative outcomes of unilateral macrostimulation of the STN-DBS in PD patients using a neuromotor symptom registration device (CATSYS 2000 System). METHODS: We studied 12 consecutive PD patients who received staged unilateral STN-DBS implants and 10 male control subjects free of neurologic deficits using a simple portable system with two sensors: a tremor pen and a touch recording plate. Results revealed excellent test-retest reliability for postural tremor in control subjects. PD patients were evaluated preoperatively during "off" state and intraoperatively for rest, postural tremor intensity, and frequency of finger tapping. Comparisons between premacrostimulation and postmacrostimulation were made using analysis of variance for repeated measures. RESULTS: Electronic rest tremor registration revealed a mean improvement of x 12.5 in tremor intensity measurements in the stimulated/contralateral side (p = 0.002). An overall x 3.8 improvement was registered on the nonstimulated/ipsilateral side. Significant improvements after STN-DBS were also recorded for postural tremor and frequency of finger tapping. CONCLUSION: Using a noninvasive, simple, and sensitive electronic recording method of intraoperative motor symptom registration, we were able to supplement short-term clinical observation by objectively quantifying the characteristics of tremor and finger tapping in response to subthalamic nucleus deep brain macrostimulation.


Assuntos
Estimulação Encefálica Profunda/métodos , Eletrodiagnóstico/métodos , Hipocinesia/diagnóstico , Doença de Parkinson/fisiopatologia , Doença de Parkinson/cirurgia , Tremor/diagnóstico , Adulto , Idoso , Braço/inervação , Braço/fisiopatologia , Encéfalo/fisiopatologia , Encéfalo/cirurgia , Eletrodos Implantados , Eletrodiagnóstico/instrumentação , Feminino , Dedos/inervação , Dedos/fisiopatologia , Lateralidade Funcional/fisiologia , Humanos , Hipocinesia/etiologia , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/métodos , Projetos Piloto , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Resultado do Tratamento , Tremor/etiologia
13.
J Chromatogr A ; 1154(1-2): 87-96, 2007 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-17449048

RESUMO

A solvent extraction procedure of freeze-dried aliquots followed by the analysis of phenolic compounds by reversed-phase high-performance liquid chromatography (RP-HPLC) with photodiode array detection (DAD) has been developed for the analysis of polyphenolic compounds in fruit juices. This methodology is focussed on the characterization of fruit juices, mainly for quality control purposes. The effects of experimental variables, such as solvent composition and volume and time and temperature on extraction, have been studied. A unique gradient program for the separation of several phenolic classes (hydroquinones, hydroxybenzoic acids, flavan-3-oles, hydroxycinnamic acids, coumarins, flavanones, flavones, dihydrochalcones and flavonols) has been optimized, using standards of 55 commercially available phenolic compounds present in fruits, as well as representative real extracts from fruit juices. All phenolic compounds showed a high repeatability within-day (n=5) and between days (n=3) in peak area (RSD<8%) and excellent stability of their retention times. High precision was also observed in calibration slopes (RSD<8%). Detection limits ranged between 0.005 and 0.03 microg/mL for the different detected polyphenols. Complete recoveries (98-100%) were obtained for the majority of the phenolic structures of all representative phenolic families present in fruits. The method was successfully employed to measure diverse phenolic families in juices from 18 different fruits and consequently could be used for evaluate the quality of fruit juices.


Assuntos
Bebidas/análise , Cromatografia Líquida de Alta Pressão/métodos , Flavonoides/análise , Frutas/química , Fenóis/análise , Citrus/química , Fragaria/química , Malus/química , Polifenóis , Reprodutibilidade dos Testes
14.
Arq. bras. med. vet. zootec ; 58(4): 550-555, ago. 2006. ilus, tab
Artigo em Inglês, Português | LILACS | ID: lil-438724

RESUMO

This study reports the occurrence of Learedius learedi Price 1934 (Digenea, Spirorchiidae) in Chelonia mydas Linnaeus 1758 (Testudines, Chelonidae) in Brazil. Eleven animals were included in this study, 54.6 percent of them were parasitized. Two hundred and fifty five parasite specimens were recovered from heart, liver, spleen, lungs, kidneys, mesenterium, and body wash. Results contribute to the knowledge about the helminthofauna of marine chelonian and their geographical distribution. This is the first report of L. learedi in the Southwestern Atlantic.


Relata-se a ocorrência de Learedius learedi Price 1934 (Digenea, Spirorchiidae) em Chelonia mydas Linnaeus 1758 (Testudines, Chelonidae) no Brasil. Onze animais foram examinados e destes, 54,6 por cento estavam parasitados. Duzentos e cinqüenta e cinco exemplares de L. learedi foram recuperados de órgãos (coração, fígado, baço, pulmões, rins, mesentério) e do lavado corporal dos animais. Os resultados contribuem para o conhecimento da helmintofauna de quelônios marinhos e sua distribuição geográfica. Este é o primeiro registro da ocorrência de L. learedi na região do Atlântico Sul Ocidental.


Assuntos
Epidemiologia/tendências , Répteis/parasitologia , Trematódeos/isolamento & purificação
15.
Bone Marrow Transplant ; 35(10): 991-5, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15806126

RESUMO

The purpose of this study was to identify risk factors for hypothyroidism after bone marrow transplantation (BMT) for high-risk or relapsed acute lymphoblastic leukaemia (ALL) in children. In all, 388 children with acute lymphoblastic leukaemia underwent allogeneic bone marrow transplantation between 1984 and 1994. Overall 5-year survival was 54.6%. Thyroid function was assessed in the 153 patients with more than 5 years of follow-up. In total, 16 patients developed uncompensated hypothyroidism (UH) and 46 compensated hypothyroidism (CH) a median of 2.9 and 2.7 years, respectively, after BMT. Thyroid dysfunction-free survival rates were 73.2% after 5 years and 59.2% after 10 years. Three factors were significantly associated with the onset of hypothyroidism, namely age, bone marrow transplantation in second remission, and single-dose total body irradiation (TBI). Ultrasonography of the thyroid showed nodules in 10 of 35 patients. The median time from BMT to nodule detection was 7.8 years. Cytology (n=5) and surgery (n=4) showed no evidence of thyroid cancer. Four of the 14 patients who received cytoreduction without TBI but with busulphan and cyclophosphamide developed UH (n=2) or CH (n=2). We concluded that children who undergo BMT for ALL are at a high risk of subsequent thyroid dysfunction.


Assuntos
Transplante de Medula Óssea/efeitos adversos , Hipotireoidismo/etiologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicações , Fatores de Risco , Sobreviventes , Transplante Homólogo , Irradiação Corporal Total/efeitos adversos
16.
Anal Bioanal Chem ; 379(3): 464-75, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15118797

RESUMO

Polyphenolic compositions of Basque and French ciders were determined by HPLC-DAD following thiolysis, in order to characterise and differentiate these beverages and then develop a classification system capable of confirming the authenticities of both kinds of cider. A data set consisting of 165 cider samples and 27 measured features was evaluated using multivariate chemometric techniques, such as cluster analysis and principal component analysis, in order to perform a preliminary study of data structure. Supervised pattern recognition techniques such as linear discriminant analysis (LDA), K-nearest neighbours (KNN), soft independent modelling of class analogy (SIMCA), and multilayer feed-forward artificial neural networks (MLF-ANN) attained classification rules for the two categories using the chemical data, which produced satisfactory results. Authentication systems obtained by combining two of these techniques were proposed. We found that SIMCA and LDA or KNN models achieved 100% hit-rates, since LDA and KNN permit the detection of every Basque cider and SIMCA provides a model for Basque cider that excludes all French ciders. Polyphenolic profiles of the ciders provided enough information to be able to develop classification rules for identifying ciders according to their geographical origin (Basque or French regions). Chemical and organoleptic differences between these two types of cider are probably due to the original and distinctive cidermaking technologies used for their elaboration. Using polyphenic profiles, about 80% of French ciders could be distinguished according to their region of origin (Brittany or Normandy). Although their polyphenolic profiles did not provide enough information to achieve an authentication system for Breton and Norman ciders.

17.
J Food Prot ; 67(12): 2786-91, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15633687

RESUMO

The levels of polycyclic aromatic hydrocarbons (PAHs) were determined by reversed-phase high-performance liquid chromatography with fluorescence detection in different fatty foods from a Spanish market. The average concentration of the sum of total PAHs in edible vegetable oils was below 25 ng/g, whereas the sum of heavy PAHs did not surpass 5 ng/g. Olive pomace oils obtained before the summer of 2001 were an exception because they were highly contaminated. The effects of different technological processes, such as bleaching, deodorization, and hydrogenation, on PAH concentration in edible oils have been studied. The PAH profiles, as well as the influence of cooking procedures, of other fatty foods (margarine, mayonnaise, and oils from canned fishes) have been examined.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Contaminação de Alimentos/análise , Manipulação de Alimentos/métodos , Hidrocarbonetos Policíclicos Aromáticos/análise , Qualidade de Produtos para o Consumidor , Análise de Alimentos , Humanos , Azeite de Oliva , Óleos de Plantas/análise , Sensibilidade e Especificidade , Espanha
18.
J Chromatogr A ; 988(1): 33-40, 2003 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-12647819

RESUMO

A solid-phase extraction (SPE) method for sample clean-up, followed by reversed-phase high-performance liquid chromatography (HPLC) with fluorescence detection is reported for the determination of polycyclic aromatic hydrocarbons (PAHs) in edible oils. The effects of experimental variables, such as washing and elution solvents, sample solvent and drying time have been studied using C18 cartridges. Recoveries and selectivity using other sorbent materials (C8, C2, CH, PH and NH2) were also examined, with C18 being the best one. The recoveries ranged between 50 and 103% depending on the molecular mass of the PAH. The limits of quantitation were lower than 1 ng/g for most PAHs and good precision was achieved. The method was validated using certified reference materials.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Óleos/química , Compostos Policíclicos/análise , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrometria de Fluorescência
19.
J Food Prot ; 65(1): 161-6, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11808788

RESUMO

An accelerated solvent extraction (ASE) procedure has been optimized for the determination of synthetic acaricides (amitraz, bromopropylate, cymiazole, coumaphos, T-fluvalinate, and flumethrin) and their residues in honey by reversed-phase high-performance liquid chromatography. The effects of experimental variables such as solvent composition, temperature, static extraction time, and solvent flush volume on the ASE efficiency have been studied. The acaricides were extracted by hexane-propanol (1/3, vol/vol) at 95 degrees C and 2.000 psi for 8 min. Recovery values of between 53 and 108% were achieved with the different substances, with coefficients of variation between 2 and 13% and limits of detection from 0.01 to 0.2 microg/g.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Mel/análise , Inseticidas/análise , Resíduos de Praguicidas/análise , Contaminação de Alimentos , Solventes , Espectrofotometria Ultravioleta , Temperatura , Fatores de Tempo
20.
J Agric Food Chem ; 49(12): 5835-42, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11743771

RESUMO

A study on the possible degradation of amitraz, bromopropylate, coumaphos, chlordimeform, cymiazole, flumethrin, and tau-fluvalinate during the storage of honey was carried out by HPLC. Except amitraz, the other acaricides are stable in this medium for at least 9 months. Degradation studies of amitraz in honey and beeswax were carried out; the degradation products detected in both matrices were 2,4-dimethylphenylformamide (DMF) and N-(2,4-dimethylphenyl)-N'-methylformamidine (DPMF). The reaction rate constants and the half-lives of the amitraz degradation in honey and wax were calculated. Amitraz was nearly completely degraded within 1 day in beeswax and within 10 days in honey. When amitraz-spiked combs are recycled into new beeswax, DMF was found to be the principal degradation product left in pure wax.


Assuntos
Mel/análise , Ceras/química , Animais , Abelhas , Biodegradação Ambiental , Cromatografia Líquida de Alta Pressão , Meia-Vida , Inseticidas/farmacocinética , Cinética , Fatores de Tempo , Toluidinas/farmacocinética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA