A Simple and Rapid in situ Preconcentration Method for Trace Ammonia Nitrogen in Environmental Water Samples Using a Solid-Phase Extraction Followed by Spectrophotometric Determination

Sensitive Method for the Oxidation-determination of Trace Hydroxylamine in Environmental Water Using Hypochlorite Followed by Gas Chromatography

“…We have developed simple and/or sensitive methods for the determination of chemical species, such as dissolved sulfide, [1][2][3] phosphate, 4,5 ammonia, 6,7 nitrite, 8 and hydrazine 9 in environmental water. Dissolved sulfide in environmental water is produced from microbial sulfate reduction.…”

Determination of Trace Hydrazine in Environmental Water Samples by in situ Solid Phase Extraction

“…Therefore, there is no need to bring back a large amount of water samples from the field. We have already developed in situ preconcentration methods for the determination of dissolved sulfide, manganese, iron(II), and ammonia nitrogen in environmental water samples by use of solid-phase extraction technique [12][13][14][15] for field work. In this study, we developed a simple and rapid method for the in situ preconcentration of hydrazine in environmental waters.…”

Collection of Indonaphthol Blue on a Membrane Filter for the Spectrophotometric Determination of Ammonia with 1-Naphthol and Dichloroisocyanurate

“…In these methods, however, the addition of nitroprusside is indispensable for these color development. Methods using thymol, [10][11][12][13][14][15] instead of phenol, were also reported. In these methods, the addition of acetone and the use of solid-phase extraction are performed to obtain high sensitivity.…”

“…The solid-phase extraction was based on the formation of an ion pair between the indophenol blue derivative and a cationic surfactant. 11,[13][14][15] The ion pair with high hydrophobicity could be collected on the solid-phase, which was either a filter, 11,13,15 or a column packed with octadecyl group-bonded silica gel.…”

“…10,11 Or, to reduce the reaction time, nitroprusside had to be used. [12][13][14][15] Modified Berthelot reactions using 1-naphthol, instead of phenol, were developed, [16][17][18][19] including our report which performed flow injection analysis. 19 In the methods, the indophenol blue derivative was formed without nitroprusside in the modified Berthelot reaction; however, it was difficult to apply for the determination of the μg L -1 level as ammonium ion.…”