Dinitro-ortho-cresol Research Articles

Molecularly Imprinted Polymer Solid-Phase Extraction (MISPE) for the Determination of Dinitro-ortho-cresol (DNOC) and Its Risk Assessment in Tomatoes

In this study, the molecularly imprinted polymer solid-phase extraction (MISPE) method for the determination of dinitro-ortho-cresol (DNOC) before HPLC (High-performance liquid chromatography) analysis was conducted. This study aims to analyze the sorption behavior and the potential use of molecularly imprinted polymers (MIP) for DNOC extraction. MIP was prepared using a combination of methacrylic acid as the functional monomer; ethylene glycol dimethacrylate as the crosslinker, benzoyl peroxide as the initiator, and acetonitrile as the porogen. The results showed that the optimum adsorption of the material was achieved at pH 5 for a contact time of 30 min with an adsorption capacity of 137 mg/g. The ideal eluent for desorption was a mixture of methanol and acetic acid with a ratio of 3:1. The calculations showed that the adsorption process followed the Sips adsorption isotherm model (n = 0.967), which indicated adsorption on both homogeneous and monolayer surfaces. Reusability studies that were conducted via three consecutive adsorption-desorption cycles resulted in recovery values of 109.4%, 108.8%, and 101.1%. The concentration of DNOC obtained from tomato samples was 0.65 mg/kg with a recovery rate of 87.17%; this was within the tolerable range between 80% and 110%. Based on the high recovery and low LoQ, this method can be used to quantify DNOC quickly.

Detection of Anti-viral Drug Riamilovir and Herbicides in Aqueous Media by Using Pyrene-based Fluorescent Chemosensors

Two ethyleneglycol esters of 1-pyrene carboxylic acid were studied as chemosensors for the fluorescence “turn-off” detection of two nitro-containing analytes, such as antiviral drug Riamilovir (Triazavirin ®) and herbicidal agent dinitro-ortho-cresol (DNOC). In both cases the dramatic fluorescence quenching was observed with quenching constants as high as 3·104 M-1 and limits of detection (LOD) as low as 100 ppb.

Effects of Five Substances with Different Modes of Action on Cathepsin H, C and L Activities in Zebrafish Embryos.

Cathepsins have been proposed as biomarkers of chemical exposure in the zebrafish embryo model but it is unclear whether they can also be used to detect sublethal stress. The present study evaluates three cathepsin types as candidate biomarkers in zebrafish embryos. In addition to other functions, cathepsins are also involved in yolk lysosomal processes for the internal nutrition of embryos of oviparous animals until external feeding starts. The baseline enzyme activity of cathepsin types H, C and L during the embryonic development of zebrafish in the first 96 h post fertilisation was studied. Secondly, the effect of leupeptin, a known cathepsin inhibitor, and four embryotoxic xenobiotic compounds with different modes of action (phenanthrene—baseline toxicity; rotenone—an inhibitor of electron transport chain in mitochondria; DNOC (Dinitro-ortho-cresol)—an inhibitor of ATP synthesis; and tebuconazole—a sterol biosynthesis inhibitor) on in vivo cathepsin H, C and L total activities have been tested. The positive control leupeptin showed effects on cathepsin L at a 20-fold lower concentration compared to the respective LC50 (0.4 mM) of the zebrafish embryo assay (FET). The observed effects on the enzyme activity of the four other xenobiotics were not or just slightly more sensitive (factor of 1.5 to 3), but the differences did not reach statistical significance. Results of this study indicate that the analysed cathepsins are not susceptible to toxins other than the known peptide-like inhibitors. However, specific cathepsin inhibitors might be identified using the zebrafish embryo.

Effect of dinitroorthocresol (DNOC) on physiology and morphology of soil fungi. II. Effect of DNOC on uptake of nitrate and contents of some N-organic fractions in the mycelium

The purpose of the investigation was to study the influence of nitrophenol pesticide (DNOC) on nitrogen metabolism measured by growth reduction in the presence of low doses of DNOC. It was established that DNOC (5; 10 mcg/ml) increased the uptake of nitrates from the culture medium which was connected with an increase of the total content of low molecular weight nitrogen compounds and the amine fraction. In the presence of DNOC the quality and quantity of free amino acids was changed On the other hand low concentrations of DNOC decreased the amount of high molecular weight compounds of nitrogen in the mycelium.

Influence of dinitroorthocresol (DNOC) on physiology and morphology of soil fungi. III. The effect of various concentrations of DNOC on spore germination activity and morphology of germ tubes

In the present paper low concentrations (l -10 mcg/ml) of DNOC, in general, were not found to restrain germination of fungal spores. High concentrations (25-200 mcg/ml) were sporostatic and sporocidal Disturbances of fungal spore germination in the presence of DNOC were often accompanied by morphological changes of spores and germ tubes, <i>Mucor mucedo</i> under the influence of DNOC developed budding cels besides hyphae.

Токсикокинетика ДНОК при применении потенциального антидота МИГУ-2

В статье представлены результаты экспериментального исследования эффективности применения антидота МИГУ-2 при отравлении динитроортокрезолом (ДНОК), который используется в промышленности и сельском хозяйстве. На основании сравнительных параметров токсикокинетики и токсикодинамики ДНОК у экспериментальных животных в условиях использования антидота и без него сделан вывод об эффективности и детоксикационных свойствах МИГУ-2.

The toxicity of the dinitrocresols. I. 4:6 Dinitro-ortho-cresol and its simpler derivatives.

The toxicity of the dinitrocresols. I. 4:6 Dinitro-ortho-cresol and its simpler derivatives.

Nitrophenols in precipitation

From 1995 to 1998 the concentrations of 4-nitrophenol, 2-methyl-4-nitrophenol, 3-methyl-4-nitrophenol, dinitro-ortho-cresol (DNOC) and 2,4-di-nitrophenol were measured monthly by HPLC in precipitation at eight different locations in Bavaria (Germany). Samples were collected by purpose-constructed computerised rainwater samplers which record electronically various sensor data each hour and adjust the sample temperature to 4°C. The highest nitrophenol (NP) concentrations were measured for 4-NP. The median at all locations is higher than 1 μg/l. The median of the other NPs ranges between 0.2 and 0.8 μg/l. Considering the rain amounts the highest depositions were calculated for the regions Spessart, Bayerischer Wald and Chiemgauer Alpen. The median of 4-NP depositions extents to 200 μg/(month m 2). The highest medians of the other NP depositions reach approximately 50 μg/(month m 2).

The Contro of Esca : Status and Perspectives

The development of an effective control strategy for esca greatly depends on major progress in understanding the disease biology and epidemiology. Experimental trials were carried out in vineyards and single infected vines in order to evaluate the effectiveness of different fungicides, application methods and cultural practices in controlling esca: experiences with sodium arsenite, dinitro-orthocresol, fosetyl Al, triazoles and first attempts with Trichoderma are discussed. Ongoing trials show promising results with fosetyl Al activity against Phaeoacremonium spp. under laboratory and greenhouse conditions, with the prospect of a favourable effect on esca control. Research is now being focused on the potential of a control strategy to prevent or reduce the establishment and development of the disease. The management of esca should be based on the age of the plant, the stage of the infection as well as the degree of spread of the disease.

Phase partitioning of phenol and nitrophenols in clouds

During five different cloud events at the summit of Great Dun Fell (GDF) the gas and liquid phases of clouds were collected simultaneously. Phenol, 2-nitrophenol (2-NP), 4-nitrophenol (4-NP), 2,4-dinitrophenol (2,4-DNP) and dinitroorthocresol (DNOC) were analysed in both phases and their partitioning between the phases was studied. The Henry constants derived from the field experiments were compared with those calculated from data for water solubility and vapour pressure and with experimentally determined Henry constants. For 4-nitrophenol the observed distribution between cloud water and air shows significantly higher gas-phase values than expected. For 2-nitrophenol an enrichment in the liquid phase was found. The experimental partitioning coefficients of the other phenols are in agreement with the published values. Reasons for the observed deviations from Henry's law are discussed.

Trace analysis of pollutants in water using the photothermal interferometry as HPLC detector.

A new procedure including high performance liquid chromatography in combination with photothermal interference spectroscopy as detection device (HPLC/PIS) has been proposed, optimized and its figures of merit for pesticide residue analysis are shown. The flowing sample under study is set in one arm of a Mach-Zehnder interferometer, and its refractive index is modulated by a periodically chopped continuous wave argon ion laser. As chopper, an acousto optical modulator has been introduced to switch the excitation laser beam between different lines (457 nm, 488 nm, 514 nm) simultaneously. Thus a multi component analysis can be realized either by using an HPLC-system in front of the PIS device or by a multi line Ar(+)-laser, directly. The limit of detection of the HPLC/PIS system reached 71 microg/l of the pesticide di-nitro-ortho-cresol (DNOC).

The limit of detection in transversal photothermal deflection spectroscopy with light scattering samples

The limit of detection for the 4,6 dinitro-orthocresol (DNOC) pesticide, including small latex particles as light scattering samples in water as suspending medium, has been determined for the transversal photothermal deflection technique. The results where compared to conventional spectrophotometry. In the photothermal deflection experiments performed with a continuous Ar+-excitation beam (λ=363.8 nm) a LOD of 0.8 μg/l is achieved for the DNOC in water.

The effect of cyanamide on the release from dormancy of grapevine buds

Cyanamide (H 2CN 2) solutions and calcium cyanamide (CaCN 2) suspensions at 0.25–1.25 M caused a rapid bud opening when applied to dormant intact buds of grapevine ( Vitis vinifera L.). The H 2CN 2 had a more potent effect than the CaCN 2. It is suggested that CaCN 2 undergoes a partial hydrolysis to hydrogen cyanamide and cyanamide ions which can be the active form and react as the H 2CN 2 products. H 2CN 2 and other treatments such as wounding, hot water, dinitro-ortho-cresol (DNOC) and thiourea, increased sprouting of grapevine cuttings. Apart from thiourea, all the treatments enhanced respiration. The involvement of dormancy in blocking respiration and its possible removal is discussed.

Mutagenicity of DNOC in Drosophila melanogaster.

The insecticide/ascaricide dinitro-ortho-cresol (DNOC) was tested for mutagenicity in BASC or Muller-5 test with Drosophila melanogaster. The frequencies of induced sexlinked recessive lethals in premeiotic and postmeiotic germ cell stages of spermatogenesis were determined after exposure of adult wild-type males by oral application of DNOC. Sex-linked recessive lethals were scored in the F2 generation according to standard procedures. The mutagenic activity of DNOC at concentrations of 0.25 to 1.01 mM (50-200 ppm) in postmeiotic germ cell stages (11 lethals/1570 chromosomes tested = 0.70%) > premeiotic stages (3/1001 = 0.29%). The mutations rate in all germ cell stages was 0.59% (18/3140). The lowest effective concentration for the induction of recessive lethals in nature sperm was 0.25 mM which is 1/3 to 1/2 LD50 which is approximately 0.61 mM. The frequency of spontaneously occurring lethality was 0.06 (1/1718). The data presented here show significant differences in Kastenbaum-Bowman test. Dimethylnitrosamine (6.8 mM = 500 ppm) induced a rate of 21.0% of lethals (112/534).

Breaking Bud Rest on Detached Apple Shoots: Interaction of Gibberellic Acid with Some Rest-breaking Chemicals1

Abstract The effectiveness of rest-breaking chemicals on detached shoots of apple (Malus domestica Borkh.) was dependent on the stage of bud rest at the time of chemical application. Thiourea (TU) and dinitro-ortho-cresol (DNOC) improved budbreak on September 9, the addition of gibberellic acid (GA3) to either chemical having no additional effect. On September 23 only DNOC was effective, and its effectiveness was increased with addition of GA3. DNOC + GA3 was the only effective treatment on both October 9 and October 25 at the start of the deep rest period. TU + GA3 improved budbreak on November 11, but no treatments were effective on December 4 and December 20. On January 14, as rest weakened, GA3 alone or in combination with DNOC effectively improved budbreak. By February 5, budbreak on control shoots was good and treatment effects were not significant.

Inhibition of the ferricyanide‐Hill reaction of isolated bean leaf chloroplasts by 3,5‐diiodo‐4‐hydroxybenzonitrile (ioxynil) and related compounds

SUMMARYThe effect of ioxynil and several related compounds on the photoreduction of ferri‐cyanide by isolated bean leaf chloroplasts has been studied.In general, a close correlation was found between the herbicidal activity of these compounds and their capacity to inhibit the photoreduction; ioxynil was highly active. The established weedkiller dinitro‐ortho‐cresol (DNC) which is a less potent contact herbicide than ioxynil, was also much less effective as an inhibitor for this reaction.

Polyneuritis after exposure to dinitro-ortho-cresol.

Polyneuritis after exposure to dinitro-ortho-cresol.

Poisoning by dinitro-ortho-cresol; report of eight fatal cases occurring in Great Britain.

Poisoning by dinitro-ortho-cresol; report of eight fatal cases occurring in Great Britain.

EFFECT OF THYROID ACTIVITY UPON METABOLIC RESPONSE TO DINITRO-ORTHO-CRESOL1

THIOURACIL, thiourea and similar compounds have been shown to lower the metabolism of experimental animals, probably by depressing the ability of the thyroid gland to elaborate its hormone (Franklin, Chaikoff and Lerner, 1944; Salter and McKay, 1944; Astwood, Bissell and Hughes, 1945). However, the animal rendered hypothyroid by these drugs still is able to give an essentially normal calorigenic response to thyroxin or desiccated thyroid substance (Dempsey and Astwood, 1943; Reineke, Mixner and Turner, 1945; Meyer and Ransom, 1945; Barker, 1945). It was thought of value to study the effect of dinitro-ortho-cresol (DNC) in thiouracil-treated rats, inasmuch as the dinitrophenols have been considered to exert their metabolism-stimulating effects directly upon the peripheral tissues (Magne, Mayer and Plantefol, 1932; Tainter and Cutting, 1933).