Zobrazeno 1 - 10
of 21
pro vyhledávání: '"Fábio R. P. Rocha"'
Publikováno v:
Journal of Analytical Methods in Chemistry, Vol 2020 (2020)
Salicylic acid (SA) is an important stress signaling phytohormone and plays an essential role in physiological processes in plants. SA fractionation has been carried out batchwise, which is not compatible with the high analytical demand in agronomica
Externí odkaz:
https://doaj.org/article/1221437088dc4b7f967db82bb152ccd3
Autor:
Fábio R. P. Rocha, Elias A. G. Zagatto
Publikováno v:
Molecules, Vol 27, Iss 5, p 1563 (2022)
Chemical derivatization for improving selectivity and/or sensitivity is a common practice in analytical chemistry. It is particularly attractive in flow analysis in view of its highly reproducible reagent addition(s) and controlled timing. Then, meas
Externí odkaz:
https://doaj.org/article/2427f6ab475749489db2b125a5da8c58
Publikováno v:
Química Nova, Vol 38, Iss 7, Pp 992-994 (2015)
AbstractA device comprising a lab-made chamber with mechanical stirring and computer-controlled solenoid valves is proposed for the mechanization of liquid-liquid extractions. The performance was demonstrated by the extraction of ethanol from biodies
Externí odkaz:
https://doaj.org/article/9dbc75b6c26745caaaaf9a23b66417c6
Publikováno v:
Química Nova, Vol 33, Iss 10, Pp 2266-2271 (2010)
It is here discussed the development of a low cost analytical instrument with capacity for metals determination using atomic emission measurements in an electrothermal atomization system with a tungsten coil atomizer. The main goal was to show a new
Externí odkaz:
https://doaj.org/article/94f4f6dcfcfe4801ae44bbef922f1261
Autor:
Marcos S. Gomes, Lilian C. Trevizan, Joaquim A. Nóbrega, Sandro T. Gouveia, Fábio R. P. Rocha
Publikováno v:
Química Nova, Vol 29, Iss 4, Pp 868-871 (2006)
Simple experiments are proposed for measuring molecular absorption of chromate and dichromate ions using an atomic absorption spectrometer. The experiments can help undergraduate students in instrumental analysis courses understand important aspects
Externí odkaz:
https://doaj.org/article/3c1daf70066643988cddfb0b60ab1862
Publikováno v:
Química Nova, Vol 27, Iss 5, Pp 807-812 (2004)
Spectrophotometry is one of the most widespread analytical techniques due to its simplicity, reliability, and low-cost instrumentation for both direct measurements and coupled to other techniques or processes such as chromatography, electrophoresis a
Externí odkaz:
https://doaj.org/article/02cedf03f0034fc18e378a6b3f890300
Publikováno v:
Química Nova, Vol 25, Iss suppl 1, Pp 61-65 (2002)
Externí odkaz:
https://doaj.org/article/9a07b0ddf7f440368d4ea923e2702c8b
Publikováno v:
Química Nova, Vol 31, Iss 2, Pp 427-429 (2008)
A simple and low-cost flow cell with 30 cm optical path for spectrophotometric measurements is described. It presents desirable characteristics such as low attenuation of the radiation beam and internal volume (75 µL) comparable to that of a 1-cm co
Externí odkaz:
https://doaj.org/article/05d82d519d6e4a0a8c88afa5e2b1b2c8
Publikováno v:
Química Nova, Vol 25, Iss 6b, Pp 1191-1193 (2002)
A simple and low cost device (ca. US$ 150) that comprises two photodiodes fixed in lab-made Perspex flow cell is proposed for chemiluminescence measurements. The characteristics of the device (large observation window and reduced thickness) allow max
Externí odkaz:
https://doaj.org/article/2a23cc40a692405bae11861d6c463ab6
Publikováno v:
Química Nova, Vol 27, Iss 2, Pp 313-314 (2004)
Externí odkaz:
https://doaj.org/article/60409bf240f14f0a83f6e39f5a90dcb7