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2.
Clin Cosmet Investig Dermatol ; 16: 2893-2897, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37869532

RESUMO

Background: Cutaneous metastasis is rare in clinical practice, especially that from primary hepatocellular carcinoma (HCC), which is even rarer. Case Presentation: This report describes a male patient with HCC with cutaneous metastases to the nasal tip. The patient developed a raised nodule at the nasal tip 5 years after surgery for HCC, with surface ulceration and crusting and no obvious symptoms. Abdominal computed tomography (CT) showed an obvious mass in the liver. The skin lesions on the nasal tip were confirmed to be cutaneous metastasis of HCC by histopathological and immunohistochemical examinations. Conclusion: The incidence of cutaneous metastasis of HCC is extremely low, and nasal tip cutaneous metastasis of HCC has no specific clinical manifestations; therefore, it needs to be distinguished from rosacea rhinophyma, fungal and atypical mycobacterial infections, tumours of vascular origin, and tumours of skin appendages that occur in the nasal tip and is prone to misdiagnosis and missed diagnosis, thus requiring clinical dermatologists and otolaryngologists to be aware of such metastasis.

3.
Mol Immunol ; 156: 77-84, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36906987

RESUMO

Asthma often presents with a daily rhythm; however, the underlying mechanisms remain unclear. Circadian rhythm genes have been proposed to regulate inflammation and mucin expression. Here, ovalbumin (OVA)-induced mice and serum shock human bronchial epidermal cells (16HBE) were used in in vivo and in vitro models, respectively. We constructed a brain and muscle ARNT-like 1 (BMAL1) knockdown 16HBE cell line to analyze the effects of rhythmic fluctuations on mucin expression. Serum immunoglobulin E (IgE) and circadian rhythm genes in asthmatic mice showed rhythmic fluctuation amplitude. Mucin (MUC) 1 and MUC5AC expression was increased in the lung tissue of the asthmatic mice. MUC1 expression was negatively correlated with that of the circadian rhythm genes, particularly BMAL1 (r = -0.546, P = 0.006). There was also a negative correlation between BMAL1 and MUC1 expression (r = -0.507, P = 0.002) in the serum shock 16HBE cells. BMAL1 knockdown negated the rhythmic fluctuation amplitude of MUC1 expression and upregulated MUC1 expression in the 16HBE cells. These results indicate that the key circadian rhythm gene, BMAL1, causes periodic changes in airway MUC1 expression in OVA-induced asthmatic mice. Targeting BMAL1 to regulate periodic changes in MUC1 expression may, therefore, improve asthma treatments.


Assuntos
Fatores de Transcrição ARNTL , Asma , Animais , Humanos , Camundongos , Fatores de Transcrição ARNTL/genética , Fatores de Transcrição ARNTL/metabolismo , Asma/induzido quimicamente , Asma/genética , Asma/metabolismo , Encéfalo/metabolismo , Mucina-1/genética , Mucina-1/metabolismo , Mucinas/metabolismo , Músculos/metabolismo , Ovalbumina/metabolismo
4.
BMC Genomics ; 23(1): 696, 2022 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-36207690

RESUMO

BACKGROUND: RING (Really Interesting New Gene) zinc finger (RING-zf) proteins belong to an important subclass of zinc fingers superfamily, which play versatile roles during various developmental stages and in abiotic stress responses. Based on the conserved cysteine and histidine residues, the RING-zf domains are classified into RING-HC (C3HC4), RING-H2 (C3H2C3), RING-v, RING-D, RING-S/T, RING-G, and RING-C2. However, little is known about the function of the RING-zfs of wheat. RESULTS: In this study, 129 (93.5%) of 138 members were found in nucleus, indicating TaRING-zf were primarily engaged in the degradation of transcription factors and other nuclear-localized proteins. 138 TaRING-zf domains can be divided into four canonical or modified types (RING-H2, RING-HC, RING-D, and RING-M). The RING-M was newly identified in T. aestivum, and might represent the intermediate other states between RING-zf domain and other modified domains. The consensus sequence of the RING-M domain can be described as M-X2-R-X14-Cys-X1-H-X2-Cys-X2-Cys-X10-Cys-X2-Cys. Further interspecies collinearity analyses showed that TaRING-zfs were more closely related to the genes in Poaceae. According to the public transcriptome data, most of the TaRING-zfs were expressed at different 15 stages of plant growth, development, and some of them exhibited specific responses to drought/heat stress. Moreover, 4 RING-HC (TraesCS2A02G526800.1, TraesCS4A02G290600.1, TraesCS4B02G023600.1 and TraesCS4D02G021200.1) and 2 RING-H2 (TraesCS3A02G288900.1 and TraesCS4A02G174600.1) were significantly expressed at different development stages and under drought stress. These findings provide valuable reference data for further study of their physiological functions in wheat varieties. CONCLUSIONS: Taken together, the characterization and classifications of the TaRING-zf family were extensively studied and some new features about it were revealed. This study could provide some valuable targets for further studies on their functions in growth and development, and abiotic stress responses in wheat.


Assuntos
Secas , Triticum , Pão , Cisteína/metabolismo , Regulação da Expressão Gênica de Plantas , Histidina/genética , Histidina/metabolismo , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estresse Fisiológico/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Triticum/metabolismo , Zinco/metabolismo , Dedos de Zinco/genética
5.
J Hypertens ; 40(12): 2323-2336, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-35950998

RESUMO

BACKGROUND: Hypertension and angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin receptor blockers (ARBs) have been reported to be associated with the prognosis of COVID-19, but the findings remain controversial. Here, we conducted a systematic review to summarize the current evidence. METHODS: We retrieved all the studies by MEDLINE via PubMed, CENTRAL, and Embase using the MeSH terms until 30 April 2021. A fixed or random effect model was applied to calculate pooled adjusted odds ratio (AOR) with 95% confidence interval (CI). Interactive analysis was performed to identify the interaction effect of hypertension and age on in-hospital mortality. RESULTS: In total, 86 articles with 18 775 387 COVID-19 patients from 18 countries were included in this study. The pooled analysis showed that the COVID-19 patients with hypertension had increased risks of in-hospital mortality and other adverse outcomes, compared with those without hypertension, with an AOR (95% CI) of 1.36 (1.28-1.45) and 1.32 (1.24-1.41), respectively. The results were mostly repeated in countries with more than three independent studies. Furthermore, the effect of hypertension on in-hospital mortality is more evident in younger and older COVID-19 patients than in 60-69-year-old patients. ACEI/ARBs did not significantly affect the mortality and adverse outcomes of COVID-19 patients, compared with those receiving other antihypertensive treatments. CONCLUSION: Hypertension is significantly associated with an increased risk of in-hospital mortality and adverse outcomes in COVID-19. The effect of hypertension on in-hospital mortality among consecutive age groups followed a U-shaped curve. ACEI/ARB treatments do not increase in-hospital mortality and other poor outcomes of COVID-19 patients with hypertension.


Assuntos
COVID-19 , Hipertensão , Humanos , Pessoa de Meia-Idade , Idoso , Anti-Hipertensivos/uso terapêutico , Antagonistas de Receptores de Angiotensina/efeitos adversos , Inibidores da Enzima Conversora de Angiotensina/efeitos adversos , SARS-CoV-2 , Hipertensão/tratamento farmacológico , Prognóstico
6.
Front Plant Sci ; 13: 892105, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35574096

RESUMO

The CCHC-type zinc finger proteins (CCHC-ZFPs) play versatile roles in plant growth, development and adaptation to the environment. However, little is known about functions of CCHC-ZFP gene family memebers in Triticum aestivum. In the present study, we identified a total of 50 TaCCHC-ZFP genes from the 21 wheat chromosomes, which were phylogenetically classified into eight groups based on their specific motifs and gene structures. The 43 segmentally duplicated TaCCHC-ZFP genes were retrieved, which formed 36 segmental duplication gene pairs. The collinearity analyses among wheat and other eight mono/dicots revealed that no gene pairs were found between wheat and the three dicots. The promoter analyses of the TaCCHC-ZFP genes showed that 636 environmental stress-responsive and phytohormone-responsive cis-elements. The gene ontology enrichment analysis indicated that all the TaCCHC-ZFP genes were annotated under nucleic acid binding and metal ion binding. A total of 91 MicroRNA (miRNA) binding sites were identified in 34 TaCCHC-ZFP genes according to the miRNA target analysis. Based on the public transcriptome data, the 38 TaCCHC-ZFP genes were identified as differentially expressed gene. The expression profiles of 15 TaCCHC-ZFP genes were verified by the quantitative real-time PCR assays, and the results showed that these genes were responsive to drought or heat treatments. Our work systematically investigated the gene structures, evolutionary features, and potential functions of TaCCHC-ZFP genes. It lays a foundation for further research and application of TaCCHC-ZFP genes in genetic improvement of T. aestivum.

7.
Se Pu ; 40(6): 584-589, 2022 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-35616204

RESUMO

Ship ballast water can control the roll, trim, and draft of the ship, and thus ensuring the balance and stability of the ship in the course of sailing, and playing a vital role in the safe navigation of ships. The annual discharge of ship ballast water is very large in China. About three to five billion cubic meters of ship ballast water is discharged into offshore or inland waters every year. This water contains plankton, pathogens, and their larvae or spores. If not be handled appropriately, this will have a serious impact on the ecological environment of the discharge waters. Ballast water is usually treated by electrolysis before being discharged. Sodium hypochlorite can be generated, which can kill microorganisms; however, the by-products trihalomethanes (THMs) are cytotoxic and biotoxic. Studies have shown that THMs may cause fetal growth retardation, spontaneous abortion, or death. The concentration of THMs in drinking water is closely related to the risk of bladder cancer death. Hence, it is important to establish a method for the determination of THMs in ship ballast water. The four kinds of THMs are chloroform, dichlorobromomethane, chlorodibromomethane, and tribromomethane. At present, ship ballast water is mostly analyzed by gas chromatography (GC) using an electron capture detector (ECD) or by gas chromatography-mass spectrometry (GC-MS). Given the low boiling point of THMs, headspace injection and purge-and-trap can be used. Gas chromatography-negative chemical ionization-mass spectrometry (GC-NCI-MS), was adopted. NCI is a soft ionization technique that shows special response to compounds bearing electronegative elements or groups. THMs contain electronegative chlorine atoms and bromine atoms. Therefore, NCI is a good choice for their analysis. The samples were processed by the headspace injection technique. The NaCl content in 10 mL sample was optimized in headspace injection. The results showed that 3.0 g NaCl was the most suitable dosage. The analytes were separated on a DB-5MS UI capillary-column (30 m×0.25 mm×1.0 µm). The target compounds were quantified by using the external standard method in selected ion monitoring (SIM) mode. The four THMs were not only well separated but also showed a high response at 0.2 µg/L. The four THMs showed good linear relationships in the range of 0.2-50 µg/L, with correlation coefficients≥0.995. The limits of quantification (LOQs, S/N=10) were 0.1-0.2 µg/L, and the average recoveries of the four THMs were 90.3%-106.8% at the three spike levels of 0.2, 0.5, and 2.0 µg/L. The relative standard deviations were 1.4%-6.2%. The LOQs of the THMs in the GB/T 5750.8-2006 Standard Test Method of Drinking Water Organic Matter Index are 0.3-6.0 µg/L. It can be seen that the LOQs of the THMs are greatly reduced in this study. The proposed method is accurate, stable, and reliable, and it can be used for monitoring the four THMs in ship ballast water. The method was applied for the detection of 36 ship ballast water samples. In all cases, the detection rates of tribromomethane, chlorodibromomethane, dichlorobromomethane, and chloroform were 83.3%, 69.4%, 22.2%, and 19.4%, respectively. The detection values of tribromomethane, chlorodibromomethane, dichlorobromomethane, and chloroform were 34.25-221.5 µg/L, 3.52-41.87 µg/L, 1.52-8.56 µg/L, and 0.02-5.46 µg/L, respectively. Based on the analysis of several ship ballast water samples (electrolytic water), it was concluded that the greater the number of bromine atoms in the THMs, the higher are the detection rate and detection value in ship ballast water. Compared to chloroform, tribromomethane is more harmful to living beings. China has acceded to the International Convention on Ship Ballast Water and Sediment Control and Management. There is an urgent need to establish analysis methods with high sensitivity, good stability, and high accuracy in addition to determining standards and regulations for ship ballast water.


Assuntos
Água Potável , Navios , Bromo/análise , Clorofórmio/análise , Água Potável/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Cloreto de Sódio/análise , Trialometanos/análise , Trialometanos/toxicidade
8.
Se Pu ; 38(5): 595-599, 2020 May 08.
Artigo em Chinês | MEDLINE | ID: mdl-34213245

RESUMO

A method was established for the determination of eight vitamins E (α-, ß-, γ-, δ-tocopherol and α-, ß-, γ-, δ-tocotrienol) in vegetable oils using gas chromatography-mass spectrometry (GC-MS). The targets were extracted with methanol, and analyzed by GC-MS in the selected ion monitoring (SIM) mode after concentration to a constant volume, and quantified using the external standard method. Baseline separation were achieved for all the target compounds. The linearities of all the compounds were between 0.01 and 1 mg/L. The limits of detection (LODs) and limits of quantification (LOQs) were in the range of 0.03-0.25 mg/kg and 0.10-0.83 mg/kg, respectively. The average recoveries of all the targets in sesame oil samples were between 87.5% and 107.4% at three spiked levels (10, 50, and 250 mg/kg), and the RSDs were all less than 7.5%. The tocopherols and tocotrienols contents in sesame oil samples and in six lower-price vegetable oils (soybean, rapeseed, sunflower, peanut, corn and palm oils) were determined by the above mentioned method. The results showed that the vitamin E profiles of sesame oil were significantly different from those of the other six vegetable oils. Therefore, vitamin E can be used as a discriminating parameter for detecting the adulteration of sesame.


Assuntos
Análise de Alimentos , Contaminação de Alimentos/análise , Óleos de Plantas/análise , Tocotrienóis/análise , Vitamina E/análise , Cromatografia Gasosa-Espectrometria de Massas , Óleo de Gergelim/análise
9.
Se Pu ; 37(1): 21-26, 2019 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-30693705

RESUMO

For the determination of organo-tin residues in edible vegetable oil, a method was developed based on gas chromatography-mass spectrometric (GC-MS) with positive chemical ionization (PCI). The edible oil samples were first dissolved by cyclohexane-ethyl acetate (1:1, v/v), and then purified by gel permeation chromatography (GPC). After derivatization by sodium tetraethylborate, the samples were analyzed by GC-MS with PCI source in the single ion monitor (SIM) mode. The seven organo-tin compounds showed good linear relationships in the range of 20-2000 µg/L and the correlation coefficients exceeded 0.99. The limits of quantitation (LOQs) and the average recoveries of the seven organo-tin compounds were 0.3-1.2 µg/kg and 66.2%-103.2%, respectively, and the relative standard deviations were less than 11.5% at three spike levels (0.05, 0.10, and 0.20 mg/kg). The method showed good linearity and high sensitivity and can be used for the determination of organo-tin residues in edible vegetable oil.


Assuntos
Contaminação de Alimentos/análise , Compostos Organometálicos/análise , Resíduos de Praguicidas/análise , Óleos de Plantas/análise , Estanho/análise , Cromatografia em Gel , Cromatografia Gasosa-Espectrometria de Massas , Verduras
10.
Se Pu ; 37(1): 27-31, 2019 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-30693706

RESUMO

A method was established for the determination of five acylpyrazole pesticide residues in edible vegetable oils using gas chromatography-negative chemical ionization-mass spectrometry (GC-NCI-MS). The pesticides were extracted from a sample with acetonitrile under freezing conditions. A simple cleanup step known as QuEChERS was then conducted. After being identified by GC-NCI-MS, the extracts were quantified using an external standard method that employs a matrix correction standard curve. The linearity of the method was good between 20 and 1000 µg/L, and all limits of quantification were less than 2 µg/kg. Recoveries of all pesticides were in the range of 82.7%-112.4% at the three spiked levels of 0.01, 0.02, and 0.05 mg/kg, and all relative standard deviations were not more than 12.3%. Therefore, this method can be used to determine the residues of acylpyrazole pesticides in edible vegetable oils.


Assuntos
Contaminação de Alimentos/análise , Resíduos de Praguicidas/análise , Óleos de Plantas/análise , Cromatografia Gasosa-Espectrometria de Massas , Verduras
11.
Se Pu ; 37(1): 32-39, 2019 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-30693707

RESUMO

A method was developed for the simultaneous determination of 10 perfluorinated carboxylic acid compounds in water by gas chromatography-mass spectrometry coupled with negative chemical ionization (GC-NCI-MS). Perfluorinated carboxylic acid compounds were derivatized by trifluoro-N-methyl-N-(trimethylsilyl) acetamide (MSTFA) as the trimethylsilyl derivatization reagent. The water sample was purified and enriched through a weak anion exchange solid phase extraction column and analyzed via GC-NCI-MS. The sample pretreatment, derivation and instrument conditions were optimized. The results showed that the linearity of the 10 perfluorinated carboxylic acid compounds was good in the range of 0.1-10 mg/L with correlation coefficients of 0.9956-0.9993. The limits of detection (LODs) and limits of quantification (LOQs) were 0.5-1.5 µg/L and 1.5-4.5 µg/L, respectively. The spiked recoveries of the blank samples ranged from 70.2% to 112.6% with the relative standard deviations (RSDs) between 2.1% and 14.5% (n=6). The method is simple, sensitive, accurate and precise, and can be used to detect the 10 perfluorinated carboxylic acid compounds in water.

12.
Se Pu ; 35(11): 1177-1183, 2017 Nov 08.
Artigo em Chinês | MEDLINE | ID: mdl-29372764

RESUMO

A method for the simultaneous determination of fenbutatin oxide, triphenyltin and cyhexatin in apples and cabbages was developed by gas chromatography-mass spectrometry coupled with two different ionization techniques, electron impact (EI) ionization and positive chemical ionization (PCI). At first, the samples were digested by hydrobromic acid, and extracted by acetone-hexane (1:2, v/v). The extracts were derivatized by sodium tetraethylborate as the derivatization reagent, and cleaned up by the Florisil SPE columns. Finally, the samples were analyzed by GC-EI/MS and GC-PCI/MS in selected ion monitoring (SIM) mode. The results showed that good linearities were obtained with correlation coefficients (r2) greater than 0.997 for fenbutatin oxide in the range of 75-500 µg/L in both foods, triphenyltin in the range of 50-1000 µg/L in cabbages and 50-500 µg/L in apples and cyhexatin in the range of 50-1000 µg/L in the two foods. The accuracy was checked at three spiked levels (50, 100 and 200 µg/kg) in cabbages and apples. The limits of detection (LODs, S/N=3) were 0.01-0.05 mg/kg (EI) and 0.01-0.02 mg/kg (PCI), and the limits of quantifications (LOQs, S/N=10) were 0.03-0.16 mg/kg (EI) and 0.02-0.06 mg/kg (PCI). The average recoveries ranged from 59.24%-97.36% (apples) and 50.54%-94.54% (cabbages) in the mode of EI, and the corresponding values were 65.38%-95.86% and 62.56%-90.44% in the mode of PCI. The relative standard deviations (RSDs) were all less than 6.9% (n=6). The PCI method can be used to improve the accuracy in comparing with the EI, in terms of good selectivity and high sensitivity.


Assuntos
Brassica/química , Análise de Alimentos/métodos , Malus/química , Resíduos de Praguicidas/análise , Cromatografia Gasosa-Espectrometria de Massas , Limite de Detecção , Compostos Orgânicos de Estanho , Compostos de Trialquitina
13.
Se Pu ; 35(12): 1224-1228, 2017 Dec 08.
Artigo em Chinês | MEDLINE | ID: mdl-29372771

RESUMO

A method was established for the determination of fipronil and its metabolites in eggs and egg products with gas chromatography-negative chemical ionization-mass spectrometry (GC-NCI-MS). The targets were extracted from samples with acetonitrile, and followed by a simple cleanup step known as dispersive solid-phase extraction QuEChERS. The extracts were determined by GC-NCI-MS, and quantified by external standard method with matrix correction standard curves. The recoveries were in the range of 87.0% to 99.3% at four spiked levels (0.1, 2.0, 4.0 and 20.0 µg/kg), and all RSDs were not more than 12.7% for the four analytes. The linearity of the method was good between 0.005 and 0.10 mg/L, and all LOQs were less than 0.10 µg/kg. So this method can be used to determine the residues of fipronil and its metabolites in eggs and egg products.


Assuntos
Ovos/análise , Resíduos de Praguicidas/análise , Pirazóis/análise , Cromatografia Gasosa-Espectrometria de Massas , Espectrometria de Massas , Extração em Fase Sólida
14.
Se Pu ; 32(7): 741-5, 2014 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-25255567

RESUMO

A method was developed for the determination of four insecticide residues in honey and royal jelly by gas chromatography-negative chemical ionization mass spectrometry (GC-NCI/MS). The honey and royal jelly samples were treated with different preparation methods as the result of the different components. The honey sample was extracted with ethyl acetate and cleaned up with primary second amine, and the royal jelly sample was extracted with acetonitrile-water (1:1, v/v), and cleaned up with a C18 solid-phase extraction column. Finally, the extracts of the honey and royal jelly were analyzed by GC-NCI/MS in selected ion monitoring (SIM) mode separately. External standard calibration method was used for quantification. The linearities of calibration curves of the four insecticides were good with the correlation coefficients greater than 0.99 in the range of 50-500 microg/L. The limits of the detection (LODs) of the four insecticides were in the range of 0.12- 5.0 microg/kg, and the limits of the quantification (LOQs) were in the range of 0.40-16.5 microg/kg. The recoveries of the four insecticides spiked in honey and royal jelly at three spiked levels (10, 15 and 20 microg/kg) were in the range of 78.2 -110.0%, and the relative standard deviations (RSDs) were all below 14%. The sensitivity and selectivity of this method were good with no interfering peaks. The proposed method is simple quick and effective to analyze the four insecticide residues in honey and royal jelly.


Assuntos
Ácidos Graxos/análise , Mel/análise , Inseticidas/análise , Resíduos de Praguicidas/análise , Cromatografia Gasosa , Cromatografia Gasosa-Espectrometria de Massas , Limite de Detecção , Extração em Fase Sólida
15.
Se Pu ; 31(1): 22-6, 2013 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-23667985

RESUMO

A reversed-phase high performance liquid chromatography coupled with tandem mass spectrometric (LC-MS/MS) method was developed for the determination of 4-chlorophenoxyacetic acid, 6-benzylaminopurine, enrofloxacin and norfloxacin residues in sprouts and source beans. The sample was extracted by acetonitrile containing 0.1% acetic acid and concentrated. The chromatographic analysis was carried out on a C18 column with methanol and 0.1% formic acid solution as the mobile phases in gradient elution program. The MS analysis was set in electrospray ionization mode and separated to two segments of positive and negative modes. The precursor ions were m/z 189.9, 226.1, 359.9 and 320.1, while the product ions for quantification were m/z 127.0, 91.2, 315.9 and 276.2 for 4-chlorophenoxyacetic acid, 6-benzylaminopurine, enrofloxacin and norfloxacin, respectively. The calibration curves showed good linearity in the range of 5 - 200 microg/L with correlation coefficients more than 0.995. The limits of detection (LODs) were 1 microg/kg and the limits of quantification (LOQs) were 5 microg/kg for the four compounds spiked in mung bean sprouts and mung beans. The recoveries of the four compounds spiked at three levels of 5.0, 10.0 and 20.0 microg/kg ranged from 70% to 91%, with the relative standard deviations (RSDs) less than 14%. The method established is accurate, sensitive, simple, and has considerable advantages in the analysis of the four kinds of illegal additive residues in sprouts and beans simultaneously.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Fabaceae/química , Contaminação de Alimentos/análise , Espectrometria de Massas em Tandem/métodos , Verduras/química , Ácido 2,4-Diclorofenoxiacético/análogos & derivados , Ácido 2,4-Diclorofenoxiacético/análise , Compostos de Benzil , Enrofloxacina , Fluoroquinolonas/análise , Cinetina/análise , Purinas
16.
Talanta ; 84(1): 141-7, 2011 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-21315911

RESUMO

An analytical method with the technique of QuEChERS (quick, easy, cheap, effective, rugged and safe) and gas chromatography (GC)/mass spectrometry (MS) in negative chemical ionization (NCI) has been developed for the determination of 17 pyrethroid pesticide residues in troublesome matrices, including garlic, onion, spring onion and chili. Pyrethroid residues were extracted with acidified acetonitrile saturated by hexane. After a modified QuEChERS clean-up step, the extract was analyzed by GC-NCI/MS in selected ion monitoring (SIM) mode. An isotope internal standard of trans-cypermethrin-D(6) was employed for quantitation. Chromatograms of pyrethroids obtained in all these matrices were relatively clean and without obvious interference. The limits of detection (LODs) ranged from 0.02 to 6 µg kg(-1) and recovery yields were from 54.0% to 129.8% at three spiked levels (20, 40 and 60 µg kg(-1) for chili, and 10, 20 and 30 µg kg(-1) for others) in four different matrices depending on the compounds determined. The relative standard deviations (RSDs) were all below 14%. Isomerization enhancement of pyrethroids in chili extract was observed and preliminarily explained, especially for acrinathrin and deltamethrin.


Assuntos
Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Resíduos de Praguicidas/análise , Piretrinas/análise , Verduras/química , Análise de Alimentos/economia , Cromatografia Gasosa-Espectrometria de Massas/economia , Limite de Detecção , Modelos Lineares , Resíduos de Praguicidas/química , Piretrinas/química , Reprodutibilidade dos Testes , Fatores de Tempo
17.
Se Pu ; 27(4): 391-400, 2009 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-19938491

RESUMO

A screening method was developed for the determination of 107 pesticide residues in vegetables using off-line dispersive solid-phase extraction (DSPE) and gas chromatography-tandem mass spectrometry (GC-MS/MS). The pesticides interested were extracted from the samples with acetonitrile (saturated by n-hexane) containing 1% acetic acid and simultaneously separated by liquid-liquid partitioning with adding anhydrous magnesium sulfate plus sodium acetate following by a simple cleanup step known as dispersive solid-phase extraction. The extracts were determined by GC-MS/MS using external standard method. The method was reliable and stable that the recoveries of almost all pesticides were in the range from 60% to 130% at the spiked level of 10 microg/kg into four vegetable matrixes (garlic, green bean, radish 8 and spinach) and the relative standard deviations (RSDs) were all not more than 15.3%. The linearity of the method was good between 0.05 mg/L and 1 mg/L, and all limits of quantification (LOQs) less than 10 microg/kg. The method is selective with no interference, especially in the complicated garlic matrix.

18.
Se Pu ; 27(2): 176-80, 2009 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-19626844

RESUMO

A method was developed for the determination of 20 kinds of pesticide residues in soybeans and corn with the technique of offline disperse solid-phase extraction and gas chromatography-negative chemical ionization mass spectrometry (GC-NCI/MS). The pesticides interested were extracted twice from the samples with acetonitrile. The combined extract was concentrated to dryness and redissolved in acetonitrile, then cleaned up by dispersive solid-phase extraction with sorbents of N-propyl ethylene diamine (PSA), graphited carbon black, and C18, and determined and confirmed by GC-NCI/MS. The recoveries of all pesticides were in the range of 70%-130% at three spiked levels (5, 10 and 20 microg/kg), and the relative standard deviations were below than 17%. The linearity of the method was good in the concentration range of 20-400 microg/L, and limits of quantification (LOQs) were no more than 2 microg/kg. The method is selective well with no interference and suitable for the confirmatory of pesticide residues in soybeans and corn.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas/métodos , Glycine max/química , Resíduos de Praguicidas/análise , Extração em Fase Sólida/métodos , Zea mays/química , Contaminação de Alimentos/análise
19.
Se Pu ; 27(1): 91-5, 2009 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-19449549

RESUMO

A confirmatory method is proposed for the determination of 12 azole fungicide residues in beans and corn with the technique of offline disperse solid phase extraction (DSPE) and gas chromatography-negative chemical ionization mass spectrometry (GC-NCI/MS). The pesticides interested were extracted from the samples with acetonitrile containing 1% acetic acid and simultaneous liquid-liquid partitioning formed by adding anhydrous magnesium sulfate plus sodium acetate followed by a simple cleanup step known as dispersive solid-phase extraction. The aliquot was determined and confirmed by GC-NCI/MS using external standard method. The recoveries of all pesticides were between 70% and 130% at the three spiked levels, 10 microg/kg, 20 microg/kg and 40 microg/kg. The relative standard deviations were less than 13.9%. The linearity of method was good from 50 to 1 000 microg/L. The limits of quantification (LOQ) were less than 8 microg/kg. The method is selective with no interference and is suitable for the confirmatory of pesticide residues in beans and corn.


Assuntos
Fabaceae/química , Contaminação de Alimentos/análise , Fungicidas Industriais/análise , Resíduos de Praguicidas/análise , Zea mays/química , Azóis/análise , Cromatografia Gasosa-Espectrometria de Massas , Extração em Fase Sólida
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