But, in , the absence of nitrate ion impurities in fluoride NPs is determined by standard qualitative reaction with diphenylamine (diphenylamine test).
The control of amount of nitrates in colloidal solution of the NPs after each stage of centrifugation was performed by identification test using diphenylamine (diphenylamine test).
Additionally, the diphenylamine test did not reveal presence of nitrates in the NPs colloidal solution after the third stage of centrifugation (Figure 4(a)).
EXD spectroscopy and the diphenylamine test did not reveal any presence of nitrates and other precursors after 4 stages of centrifugation (12,000 revolutions/min 10 min).
Caption: Figure 4: (a) The diphenylamine test data.
The diphenylamine test was performed in elephant grass samples, and consists in adding one drop of the reagent solution (0.5g diphenylamine, 20mL distilled water, and 80mL concentrated sulfuric acid) to three drops from the plant extract on glass slides.
Diphenylamine test and nitrate dosage in elephant grass were performed, and the results of these tests associated with clinical signs and epidemiological data allowed to conclude the diagnosis of nitrate/nitrite intoxication.
At diphenylamine test, a color change from green to deep blue (Figure 1G) occurred in less than ten seconds in sap drops extracted from the plant.
The clinical signs, necropsy findings, histopathological examination, epidemiological data, the positive diphenylamine test and the nitrate dosage in grass confirmed the nitrate/nitrite intoxication.
The presence of nitrates after each stage of centrifugation was controlled via diphenylamine test
. In order to synthesize [Pr.sup.3+]:La[F.sub.3] ([C.sub.Pr] = 12%) NPs, the suitable ratio of [Pr.sub.2][O.sub.3] and [La.sub.2][O.sub.3] was taken.
Compounds interfering in the diphenylamine test
for deoxyribonucleic acid.
The diphenylamine test
for nitrates is easy to run.