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1. Analysis of Food by High Performance Liquid Chromatography Coupled with Coulometric Detection and Related Techniques: A Review

Author:
Noronha, João P.,   et al.   ; Sontag, Gerhard; Pinto, Maria I.; Burrows, Hugh D.;     Show all 4 Authors
Source:
Journal of agricultural and food chemistry 2019 v.67 no.15 pp. 4113-4144
ISSN:
1520-5118
Subject:
batch systems; derivatization; electrochemistry; electrodes; food chemistry; high performance liquid chromatography; mass spectrometry; metabolomics; oxidation; pesticides; pharmacokinetics; phenolic compounds; photochemical reactions; vitamins
Abstract:
... The development of single coulometric cells in combination with high performance liquid chromatography to dual cells and to the coulometric electrode array detector is described. An overview is given about the application of these methods in food chemistry. Easily oxidizable compounds, such as phenolic substances, pesticides, or vitamins, can be determined, as well as substances with high oxidatio ...
DOI:
10.1021/acs.jafc.9b00003

2. Effects of ultrasonic irradiation and direct heating on extraction of priority pesticides from marine sediments

Author:
Noronha, João P.,   et al.   ; Pinto, Maria I.; Vale, Carlos; Sontag, Gerhard;     Show all 4 Authors
Source:
International journal of environmental analytical chemistry 2013 v.93 no.15 pp. 1638-1659
ISSN:
1029-0397
Subject:
HCH (pesticide); alachlor; aldrin; aquatic environment; chlorfenvinphos; chlorpyrifos; coastal water; detection limit; dieldrin; endosulfan; endrin; gas chromatography-mass spectrometry; guidelines; heat; heptachlor; heptachlor epoxide; hexachlorobenzene; information sources; irradiation; lindane; marine sediments; methoxychlor; mirex; monitoring; quality control; quintozene; screening; temperature; terbuthylazine; toxic substances; trifluralin; ultrasonics; water distribution
Abstract:
... Priority pesticides (alachlor, aldrin, γ-chlordane, chlorfenvinphos, chlorpyrifos, dieldrin, 4,4′-DDT, 4,4′-DDD, 4,4′-DDE, α-endosulfan, β-endosulfan, endosulfan sulphate, endrin, α-HCH, β-HCH, γ-HCH, δ-HCH, HCB, HCBD, heptachlor, heptachlor epoxide, isodrin, methoxychlor, mirex, quintozene, terbuthylazine and trifluralin) are a group of toxic substances that are known by their persistency in the ...
DOI:
10.1080/03067319.2013.831409

3. Novel sensory surface for creatine kinase electrochemical detection

Author:
Noronha, João P.,   et al.   ; Moreira, Felismina T.C.; Dutra, Rosa A.F.; Sales, M. Goreti F.;     Show all 4 Authors
Source:
Biosensors & bioelectronics 2014 v.56 pp. 217-222
ISSN:
0956-5663
Subject:
ambient temperature; biomarkers; biosensors; bovine serum albumin; creatine; creatine kinase; cysteamine; detection limit; dielectric spectroscopy; electrochemistry; electrodes; gold; ischemia; isozymes; myoglobin; phosphates; troponin T
Abstract:
... This work describes a novel concept of biosensor for quantifying enzymes, where the substrate is immobilized directly over the working area of a screen printed electrode (Au-SPE). This concept is applied here to creatine kinase isoenzyme (CK-MB), a cardiac biomarker in ischemic conditions. It acts as a phospho-transferase on creatine (Crea), requiring the presence of phosphate. So, the phosphoryla ...
DOI:
10.1016/j.bios.2013.12.052

4. Sarcosine oxidase composite screen-printed electrode for sarcosine determination in biological samples

Author:
Noronha, João P.,   et al.   ; Rebelo, Tânia S.C.R.; Pereira, Carlos M.; Sales, M.Goreti F.; Costa-Rodrigues, J.; Silva, Fernando; Fernandes, M.H.;     Show all 7 Authors
Source:
Analytica chimica acta 2014 v.850 pp. 26-32
ISSN:
0003-2670
Subject:
analytical chemistry; biosensors; carbon; detection limit; diagnostic techniques; electrochemistry; electrodes; hydrogen peroxide; immobilized enzymes; metabolites; neoplasm cells; oxidation; prostatic neoplasms; quantum dots; urine
Abstract:
... As the prostate cancer (PCa) progresses, sarcosine levels increase both in tumor cells and urine samples, suggesting that this metabolite measurements can help in the creation of non-invasive diagnostic methods for this disease. In this work, a biosensor device was developed for the quantification of sarcosine via electrochemical detection of H2O2 (at 0.6V) generated from the catalyzed oxidation o ...
DOI:
10.1016/j.aca.2014.08.005

5. Bioactivity studies and chemical profile of the antidiabetic plant Genista tenera

Author:
Noronha, João P.,   et al.   ; Rauter, Amélia P.; Martins, Alice; Lopes, Rui; Ferreira, Joana; Serralheiro, Luísa M.; Araújo, Maria-Eduarda; Borges, Carlos; Justino, Jorge; Silva, Filipa V.; Goulart, Margarida; Thomas-Oates, Jane; Rodrigues, João A.; Edwards, Emma; Pinto, Rui; Mota-Filipe, Hélder;     Show all 16 Authors
Source:
Journal of ethnopharmacology 2009 v.122 no.2 pp. 384-393
ISSN:
0378-8741
Subject:
medicinal plants; medicinal properties; indigenous species; traditional medicine; diabetes; glycemic effect; hyperglycemia; plant extracts; butanol; antioxidant activity; acetylcholinesterase; enzyme inhibition; cytotoxicity; genotoxicity; mass spectrometry; high performance liquid chromatography; rats; animal disease models; chemical constituents of plants; flavonoids; free radical scavengers; Genista; in vitro studies; Madeira Islands; Portugal
Abstract:
... Aim of the study: Genista tenera is a plant endemic to the island of Madeira and is used in folk medicine to control diabetes. In the present work we evaluate the antihyperglycaemic activity of its n-butanol extract and determine its chromatographic profile. In addition, this extract, the ethyl acetate and diethyl ether plant extracts were studied in order to assess the plant antioxidant and acety ...
DOI:
10.1016/j.jep.2008.10.011