Determination of nitrite in estuarine waters. Automatic determination using a brucine method

Kahn, Lloyd; Brezenski, Francis T.

doi:10.1021/es60006a008

Cited by 8 publications

(2 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Dissolved inorganic nitrogen (DIN) was analyzed in 1971-1972, nitrate by the brutine procedure (Kahn and Brezenski 1967) and ammonia by the alkaline-phenolhypochlorite method, both as adapted for a Technicon AutoAnalyzer by Kluesner (1972). Organic-N was determined in midsummer 197 1 by autoanalyzer following Kjeldahl digestion (Am.…”

Section: Methodsmentioning

confidence: 99%

Nutrient internal cycling and the trophic regulation of Green Lake, Wisconsin1

Stauffer

1985

Limnology & Oceanography

View full text Add to dashboard Cite

Algal nutrients (Si, N, P) and dissolved oxygen were studied in Green Lake, Wisconsin, in 1971– 1972, and in 1978–1980 following a reduction of about 35% in total external P loading in December 1976. Despite oxic conditions, there is more P in the hypolimnion than would be expected from the dissolved oxygen and from classical Redfield stoichiometry. Because of a metalimnetic dissolved oxygen minimum in late summer, the calculation and interpretation of the hypolimnetic oxygen deficit is affected by turbulent transport of dissolved oxygen. Vertical fluxes of P into the mixed layer are important in late spring and early summer, but, owing to metalimnetic P depletion, negligible between mid‐July and mid‐October. Vertical transport of Si into the mixed layer is negligible in summer and early fall compared with inputs from the land drainage basin. Although P is high at spring turnover, epilimnetic concentrations of P are low and Secchi transparency is high by mid‐to‐late summer. These seasonal changes are caused by sedimentation of P and low seasonal inputs from the drainage basin. This P is recovered in the hypolimnion and recirculated throughout the lake at fall overturn. It causes silica limitation of the diatom bloom each succeeding spring. The total P content of Green Lake and its seasonal partition among the layers were remarkably stable between 1971 and spring 1980, despite the reduction in external loading in 1976. The hypolimnetic oxygen deficit also showed no significant change between the first and eighth decades of this century.

show abstract

Section: Methodsmentioning

confidence: 99%

Nutrient internal cycling and the trophic regulation of Green Lake, Wisconsin1

Stauffer

1985

Limnology & Oceanography

View full text Add to dashboard Cite

show abstract

“…For example, the alkaloid brucine, obtained from the seeds of the Strychnine tree (Strychnos nux-vomica L.), was described as early as 1863 for the determination of nitrate and nitric acid, 6 and was in common usage for nitrate determination until the 1970's. [7][8][9][10] However, it was not until the 1990's that the chemical basis of the brucine-based nitrate determination was thoroughly investigated and explained. Interestingly, the brucine method was largely superseded as a standard method 11,12 by a supposedly better method involving Cd-reduction of nitrate followed by diazotization and coupling with N-1-naphthylethylenediamine dihydrochloride to form a diazo dye (the Griess reaction).…”

Section: Introductionmentioning

confidence: 99%

The case for the use of unrefined natural reagents in analytical chemistry—A green chemical perspective

et al. 2010

View full text Add to dashboard Cite

An important part of the Green Chemistry philosophy is the need to develop and adopt green analytical techniques and procedures. These include the reduction of reagent and solvent usage, the minimization of solid, liquid and gaseous materials produced by analytical processes, the replacement of reagents and solvents of high occupational or environmental toxicity with much more innocuous materials, and the reduction of energy use in analytical processes. One aspect that has received little attention in this context is the use of unrefined natural reagents derived from plant and animal tissues or microbial cells. Crude plant extracts may contain chemical compounds that enable their use as indicators in acid-base or redox titrations, or as chromogenic or fluorogenic agents. Enzymes extracted from plants may be used directly in soluble form, or incorporated in biosensors or solid phase reactors, for analytical measurements, or as a means of removing interferences or performing speciation studies. The use of natural reagents in conjunction with a flow injection system can confer a number of advantages. The enhanced kinetic control that flow analysis offers may assist in avoiding undesirable side reactions that would otherwise occur using unpurified reagents. The lifetime of natural reagents may be prolonged when used in a flow analysis system because their exposure to light or air can be controlled. Any changes in response that do occur may be readily corrected by regular standard checking and recalibration. This article reviews the use of natural reagents with an emphasis on flow-based analytical systems, and makes the case for further research in this latent area of green analytical chemistry.

show abstract