Automatic wet chemical analysis as applied to pesticide residues

Author(s):  
George D. Winter ◽  
Andrés Ferrari
1994 ◽  
Vol 58 (391) ◽  
pp. 307-314 ◽  
Author(s):  
Mizuhiko Akizuki ◽  
Hirotugu Nisidoh ◽  
Yasuhiro Kudoh ◽  
Tomohiro Watanabe ◽  
Kazuo Kurata

AbstractA study of apatite crystals from the Asio mine, Japan, showed sectoral texture related to the growth of the crystal, and with optically biaxial properties within the sectors. Wet chemical analysis gave a composition Ca5(PO4)3(F0.64,OH0.38,Cl0.01)1.03 for the specimen.Additional diffraction spots were not observed in precession and oscillation X-ray photographs and electron diffraction photographs. Since the internal textures correlate with the surface growth features, it is suggested that the internal textures and the unusual optical properties were produced during nonequilibrium crystal growth. The fluorine/hydroxyl sites in hexagonal apatite are symmetrically equivalent in the solid crystal but, at a growth surface, this equivalence may be lost, resulting in a reduction of crystal symmetry. Heating of the apatite to about 850°C results in the almost complete disappearance of the optical anomalies due to disordering, which may be related to the loss of hydroxyl from the crystal.


2020 ◽  
Vol 7 ◽  
Author(s):  
Alexandre Máximo Silva Loureiro ◽  
Simone Patrícia Aranha da Paz ◽  
Rômulo Simões Angélica

One of the most important studies from historic mortars is the binder:aggregate ratio, which is usually obtained through wet chemical analysis. Instrumental techniques and benchtop equipment have become increasingly important tools in the characterization of historic materials. The analysis of such materials has become more practical, faster and more accurate, and the sample preparation methods require less and less material. Thus, this article aims to investigate the validity of the results obtained by some of the methods and techniques used in historic materials analysis and determine the possibility of estimating the binder:aggregate ratio with adequate accuracy and precision. For this purpose, historic mortars from Belém do Pará, in northern Brazil, were selected, and the following quantification techniques were employed: wet chemical analysis, XRD, DSC and XRF. The results showed that the amounts of the components in the mortars could be quantified with the use of approximately 3 g of sample, thus providing one of the main pieces of information needed for the production of a restoration mortar: the binder:aggregate ratio.


1981 ◽  
Vol 44 (333) ◽  
pp. 55-57 ◽  
Author(s):  
S. A. Williams

AbstractProbably first found in Arabia, then Moctezuma, Sonora (the type locality), finally at Tombstone, Arizona. Crystals are cubic, invariably octahedral in habit, up to 2 mm in size. Colour forest green (RHS 136A), H = 3, D = 6.4.Wet chemical analysis gave CuO 11.0%, PbO 33.0, TeO2 50.7, H2O 3.4; soluble in cold dilute acids. The strongest lines are 7.223(5), 4.170(2), 3.614(3), 3.472(4), 3.343(6), 3.036(10), 7.952(3), 2.454(5) Å. The cell indexes as cubic, a = 12.519 Å; for Z = 12, ρcalc = 6.41 g/cm3. May be anisotropic in thin section with birefringence up to 0.011; n = 2.04.


1984 ◽  
Vol 48 (348) ◽  
pp. 397-400 ◽  
Author(s):  
Satoshi Matsubara ◽  
Akira Kato ◽  
Kozo Nagashima

Abstract The first occurrence of mpororoite and anthoinite outside the African Continent has been found in an altered skarn from the Kara mine, Tasmania, forming a white powdery mixture of the two minerals pseudomorphing scheelite. The wet chemical analysis of the mixture shows WO3, Al2O3, and H2O to be the essential constituents, proving the non-essential nature of Fe2O3 in mpororoite; the original mpororoite contained high Fe2O3 substituting for Al2O3. The thermal treatment of the mixture at 100°C for 6 hours in air brings about the conversion of mpororoite into anthoinite, which re-hydrates into mpororoite, although the associated anthoinite does not. The source of Al is ascribed to the decomposition of aluminian andradite in the skarn.


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