Dinitrophenols, analysis

Fetterer, R.H., Pax, R.A. and Bennett, J.L. (1980) Praziquantel, potassium and 2,4-dinitrophenol analysis of their action on the musculature of Schistosoma mansoni. European Journal of Pharmacology 64, 31-38. 

The procedure of simultaneous extracting-spectrophotometric determination of nitrophenols in wastewater is proposed on the example of the analysis of mixtures of mono-, di-, and trinitrophenols. The procedure consists of extraction concentrating in an acid medium, and sequential back-extractions under various pH. Such procedures give possibility for isolation o-, m-, p-nitrophenols, a-, P-, y-dinitrophenols and trinitrophenol in separate groups. Simultaneous determination is carried out by summary light-absorption of nitrophenol-ions. The error of determination concentrations on maximum contaminant level in natural waters doesn t exceed 10%. The peculiarities of application of the sequential extractions under fixed pH were studied on the example of mixture of simplest phenols (phenol, o-, m-, />-cresols). The procedure of their determination is based on the extraction to carbon tetrachloride, subsequent back-extraction and spectrophotometric measurement of interaction products with diazo-p-nitroaniline. 

Sophisticated isotope experiments were also performed using H2180 (Mildred Cohn) and 32P, and various exchange reactions identified between ATP, ADP, and Pr Analysis of the mode of action of two inhibitors was also relevant. Dinitrophenol (DNP) uncoupled the association between oxidation and ATP generation (Lardy and Elvejhem, 1945 Loomis and Lipmann, 1948). Oligomycin inhibited reaction (ii) above, blocking the terminal phosphorylation to give ATP, but not apparently the formation of A C. 

Toxic nitrophenols (4-nitrophenol, 2-nitrophenol, and 2,4-dinitrophenol) present in air samples are sampled on silica gel or XAD-2 polymeric resin, extracted, and analyzed by the HPLC/DAD technique [240], Nitrophenols are also determined in rain and snow precipitations through HPLC/ UV analysis after SPE [241]. 

Continuous measurements of 2,4-dinitrophenol in River R (see Illustrative Examples 25.1 to 25.4) passing by the GWS show a superposition of sinusoidal diurnal and annual concentration variations (Eq. 25-33). Calculate how much of this variation is observed at one of the wells and determine the phase shift (in days) between the oscillations in the river and in the well. Include into the analysis also a monthly oscillation (t = 30 days). Make all calculations for the three flow regimes. 

The third step is to determine the polypeptide chain end groups. If the polypeptide chains are pure, then only one N-terminal and one C-terminal group should be detected. The amino-terminal amino acid can be identified by reaction with fluorodinitrobenzene (FDNB) (fig. 3.18). Subsequent acid hydrolysis releases a colored dinitrophenol (DNP)-labeled amino-terminal amino acid, which can be identified by its characteristic migration rate on thin-layer chromatography or paper electrophoresis. A more sensitive method of end-group determination involves the use of dan-syl chloride (see Methods of Biochemical Analysis 3B). 

Figure 6.2 demonstrates this in the case of a ground water sample from the former ammunition site in Elsnig (Germany). Many unknown compounds could be identified in the non-target analysis, e.g. 2,4-dinitrobenzoic acid (2,4-DNBA) and 3,5-dinitrophenol (3,5-DNP) which are major components (see Figure 6.2(a) and Table 6.1). 

In the case of pesticides which are not ChE inhibitors, exposure is measured by the analysis of blood and/or urine for the active ingredient or its metabolites. Baseline levels of pesticides and/or metabolites are not usually determined, with the exception of methyl bromide. In this case, a blood sample is taken to check for bromide ion before fumigators use the pesticide. Blood and urine tests are run only in the case of spills or other accidents to assist in identifying the cause of poisoning or to monitor workers in a workplace. Paraquat, chlorinated hydrocarbons, mercury, p-nitrophenol, and dinitrophenol are examples of pesticides or metabolites of pesticides that have been found in the urine of exposed workers. 

The absolute stereochemistry of the aromatic Erythrina alkaloids has been determined. An X-ray analysis of the 2-bromo-4,6-dinitrophenolate... 

The analysis of the organic components in the primers could suffer contamination from the propellant, although the results suggest that this is not the case. Dinitrophenol is probably a breakdown product of DDNP arising from the conditions used in GC/MS. 

Workers in the dinitrophenol plant should be protected in the usual way (i.e. gloves, respirators, chMige of clothes, bath, etc.). Selection of workers hMidling dinitrophenol is also recommended since it has been shown that a great mMiy people are resistant to its toxic effects, Selection is based on 15 days medical observation of each new worker in the dinitrophenol plant, in particular in the analysis of the mine every other day. A test for the presence of Mninonitrophenols is particularly importance. Usually Denien s reaction [33] is used. According to Lazarev [31], the reaction comprises acidification of the mine with 10% sulphuric acid and diazotization with sodium nitrite, followed by shaking up the prepMed solution with an ammoniacal solution of p- naphthol. If a red colour appeMS it indicates the presence of 4-amino-2-nitrophenol in the mine, while a violet shade is evidence for the presence of 2-Mnino-4-nitrophenol. 

Conclusions. The ELISA method may be a promising tool for analysis of several of the nitroaromatic compounds found at NPL hazardous waste sites. Detection of 2,4-dinitrotoluene, 1,3,5-trinitrobenzene, 2,4-dinitrophenol, and 2,4,6-trinitrotoluene at a lower limit of 1 ng/mL under the conditions of this ELISA suggest that direct detection of 10 ng/mL of these nitroaromatics may be accomplished in environmental samples without sample concentration. Investigations are underway to analyze soil and water samples to determine what, if any, matrix effects there will be in these ELISAs. 

The purpose of this chapter is to describe the analytical methods that are available for detecting, and/or measuring, and/or monitoring dinitrophenols, their metabolites, and other biomarkers of exposure and effect to dinitrophenols. The intent is not to provide an exhaustive list of analytical methods. Rather, the intention is to identify well-established methods that are used as the standard methods of analysis. Many of the analytical methods used for environmental samples are the methods approved by federal agencies and organizations such as EPA and the National Institute for Occupational Safety and Health (NIOSH). Other methods presented in this chapter are those that are approved by groups such as the Association of Official Analytical Chemists (AOAC) and the American Public Health Association (APHA). Additionally, analytical methods are included that modify previously used methods to obtain lower detection limits, and/or to improve accuracy and precision. 

Robert TA, Hagardorn AN. 1983. Analysis and kinetics of 2,4-dinitrophenol in tissues by capillary gas chromatography-mass spectrometry. J Chromatogr 276 77-84. 

With the aid of decoupling experiments and the INDOR technique, it was possible to define completely the structure and stereochemistry of erythristemine (1) with the exception of the configuration at C-11." In order to obtain the latter information, recourse was taken to A-ray analysis on the 2-bromo-4,6-dinitrophenolate salt of (1). This constitutes a new method and may be applicable elsewhere. Details of the structural and stereochemical elucidation of the interesting insecticidal alkaloid (2), which may be regarded as a ring-D degraded erythroidine structure, have appeared. ... 

A method of capillary analysis was adapted to determine the pH by Boutaric and Bouchard (1935). The method is only an approximate one, since thqy diluted the wines 1/100. A pH indicator consisting of 2 volumes of saturated (aqueous) benzyl orange, 2 volumes of saturated (aqueous)bromophenol blue was proposed by Marcilla and Feduchy (1943). The range was from 2.8 to 4.6 with colors from orange to brown to gray to blue violet and a sensitivity of about 0.2 pH unit. 

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