Fluorimetry of selenium in body fluids after digestion with nitric acid, magnesium nitrate hexahydrate, and hydrochloric acid.

A digestion procedure involving nitric acid, magnesium nitrate hexahydrate, and hydrochloric acid suffices for selenium determinations in whole blood, serum, and urine by molecular fluorescence spectrometry. To test the accuracy of the method we compared the results with those from hydride-generation atomic absorption spectrometry, and we also analyzed reference materials.

Ab Initio Molecular Dynamics Study of Aqueous Solutions of Magnesium and Calcium Nitrates: Hydration Shell Structure, Dynamics and Vibrational Echo Spectroscopy

Ab initio molecular dynamics simulations are performed to study the hydration shell structure, dynamics, and vibrational echo spectroscopy of aqueous Mg(NO3)2 and Ca(NO3)2 solutions. The hydration shell structure is probed through calculations of various ion-ion and ion-water radial and spatial distribution functions. On the dynamical side, calculations have been made for the hydrogen bond dynamics of hydration shells and also residence dynamics and lifetimes of water in different solvation environments.
Subsequently, we looked at the dynamics of frequency fluctuations of OD modes of heavy water in different hydration environments. Specifically, the temporal decay of spectral observables of two-dimensional infrared (2DIR) spectroscopy, three pulse echo peak shift (3PEPS) measurements and also of time correlations of frequency fluctuations are calculated to investigate the dynamics of vibrational spectral diffusion of water in different hydration environments in these solutions.
The OD stretch frequencies of water molecules in the vicinity of both divalent cations are found to be red-shifted and also fluctuating at a slower rate than other water molecules present in the solutions. The Mg2+ ions are found to be strongly hydrated which can be linked to their lower tendency to form contact ion-pairs and essentially no water exchange between the cationic hydration shells and bulk during the time scale of the current simulations.
The stronger hydration of Mg2+ ions make their hydration shells structurally and dynamically more rigid and make the dynamics of hydrogen bonds and vibrational spectral diffusion, as revealed through spectral observables of 2DIR and 3PEPS slower than that for the Ca2+ ions.
The structural and spectral dynamics of water molecules outside the cationic solvation shells in the Mg(NO3)2 solution are also found to be relatively slower than that of the Ca(NO3)2 solution and pure water which show the effects of stronger electric fields of Mg2+ ions extending beyond their first hydration shells. Also, water molecules in the hydration shells of the NO3 ions are found to relax at a slower rate in the Mg(NO3)2 solution which manifests the effect countercations have on anionic hydration shells for divalent metal nitrate solutions.

Effect of molten sodium nitrate on the decomposition pathways of hydrated magnesium hydroxycarbonate to magnesium oxide probed by in situ total scattering

The effect of NaNO3 and its physical state on the thermal decomposition pathways of hydrated magnesium hydroxycarbonate (hydromagnesite, HM) towards MgO was examined by in situ total scattering. Pair distribution function (PDF) analysis of these data allowed us to probe the structural evolution of pristine and NaNO3-promoted HM. A multivariate curve resolution alternating least squares (MCR-ALS) analysis identified the intermediate phases and their evolution upon the decomposition of both precursors to MgO.
The total scattering results are discussed in relation with thermogravimetric measurements coupled with off-gas analysis. MgO is obtained from pristine HM (N2, 10 °C min-1) through an amorphous magnesium carbonate intermediate (AMC), formed after the partial removal of water of crystallization from HM.
The decomposition continues via a gradual release of water (due to dehydration and dehydroxylation) and, in the last step, via decarbonation, leading to crystalline MgO. The presence of molten NaNO3 alters the decomposition pathways of HM, proceeding now through AMC and crystalline MgCO3.
These results demonstrate that molten NaNO3 facilitates the release of water (from both water of crystallization and through dehydroxylation) and decarbonation, and promotes the crystallization of MgCO3 and MgO in comparison to pristine HM. MgO formed from the pristine HM precursor shows a smaller average crystallite size than NaNO3-promoted HM and preserves the initial nano-plate-like morphology of HM.
NaNO3-promoted HM was decomposed to MgO that is characterized by a larger average crystallite size and irregular morphology. Additionally, in situ SEM allowed visualization of the morphological evolution of HM promoted with NaNO3 at a micrometre scale.

Magnesium reduces cadmium accumulation by decreasing the nitrate reductase-mediated nitric oxide production in Panax notoginseng roots.

Panax notoginseng is a traditional medicinal herb in China. However, the high capacity of its roots to accumulate cadmium (Cd) poses a potential risk to human health. Our previous study showed that nitrate reductase (NR)-dependent nitric oxide (NO) production promoted Cd accumulation in P. notoginseng root cell walls.
In this study, the role of Mg in the regulation of NO production and Cd accumulation in P. notoginseng roots was characterized. Exposure of P. notoginseng roots to increasing concentrations of Cd resulted in a linear increase in NO production.
The application of 2 mM Mg for 24 h significantly alleviated Cd-induced NO production and Cd accumulation in roots, which coincided with a significant decrease in the NR activity. Western analysis suggested that Mg increased the interaction between the 14-3-3 protein and NR, which might have been a reason for the Mg-mediated decrease in NR activity and NO production under Cd stress.
These results suggested that Mg-mediated alleviation of Cd-induced NO production and Cd accumulation is achieved by enhancement of the interaction between the 14-3-3 protein and NR in P. notoginseng roots.

Electrochemical nitrate removal with simultaneous magnesium recovery from a mimicked RO brine assisted by in situ chloride ions.

Electrochemical reduction is effective to remove nitrate but byproducts such as ammonia and nitrite would need chloride addition for indirect oxidation to nitrogen gas.
Herein, electrochemical nitrate reduction was investigated to remove nitrate from a mimicked reverse osmosis (RO) brine containing chloride that eliminates the need for external chloride addition. Both Cu/Zn and Ti nano cathodes exhibited the best performance of nitrate removal with >97 % removal in either Na2SO4 or NaCl electrolyte, although with different products.

Magnesium nitrate hexahydrate

from Bio Basic
MB0586 | 500g: 67.40 EUR

Magnesium nitrate hexahydrate

from Glentham Life Sciences
GK0164-1KG | 1 kg: 66.00 EUR

Magnesium nitrate hexahydrate

from Glentham Life Sciences
GK0164-250G | 250 g: 44.00 EUR

Magnesium nitrate hexahydrate

from Glentham Life Sciences
GK0164-500G | 500 g: 54.00 EUR

Magnesium nitrate hexahydrate

from Glentham Life Sciences
GK0164-5KG | 5 kg: 178.00 EUR

isa nitrate

from Consort
ISA31 | ea: 91.00 EUR

nitrate electrode

from Consort
ISE31B | ea: 352.00 EUR

Econazole nitrate

from TOKU-E
E001-100G | 100 g: 499.00 EUR

Econazole nitrate

from TOKU-E
E001-25G | 25 g: 208.00 EUR

Econazole nitrate

from TOKU-E
E001-5G | 5 g: 79.00 EUR

Miconazole nitrate

from TOKU-E
M005-1G | 1 g: 62.00 EUR

Miconazole nitrate

from TOKU-E
M005-5G | 5 g: 173.00 EUR

Barium nitrate

from Bio Basic
BB0119 | 1Kg: 123.08 EUR

Butoconazole (nitrate)

from MedChemExpress
HY-B0293 | 10mM/1mL: 126.00 EUR

Fenticonazole (Nitrate)

from MedChemExpress
HY-B0359 | 10mM/1mL: 134.00 EUR

Econazole (nitrate)

from MedChemExpress
HY-B0453 | 5g: 160.00 EUR

Miconazole (nitrate)

from MedChemExpress
HY-B0454A | 5g: 160.00 EUR

Sertaconazole (nitrate)

from MedChemExpress
HY-B0736A | 10mM/1mL: 113.00 EUR

Pilocarpine (nitrate)

from MedChemExpress
HY-B1006 | 100mg: 133.00 EUR

Oxiconazole nitrate

from MedChemExpress
HY-B1324 | 10mg: 133.00 EUR

Isoconazole (nitrate)

from MedChemExpress
HY-B1444 | 100mg: 158.00 EUR

Sulconazole (nitrate)

from MedChemExpress
HY-B1460A | 100mg: 133.00 EUR

Thiamine nitrate

from MedChemExpress
HY-B2223 | 10mM/1mL: 126.00 EUR

Dehydrocorydaline (nitrate)

from MedChemExpress
HY-N4238 | 1mg: 179.00 EUR

Potassium nitrate

from Bio Basic
PD0444 | 500g: 63.92 EUR

Thiamine nitrate

from Abbexa
20-abx180904 | [ 25 g: 314.00 EUR ] [ 500 g: 759.00 EUR ]

Isoconazole nitrate

from Abbexa
20-abx184134 | [ 25 g: 801.00 EUR ] [ 5 g: 370.00 EUR ]

Miconazole nitrate

from Abbexa
20-abx184229 | [ 1 g: 272.00 EUR ] [ 25 g: 592.00 EUR ] [ 5 g: 314.00 EUR ]

Silver nitrate

from Glentham Life Sciences
GK7224-100G | 100 g: 221.00 EUR
Complete nitrate reduction to nitrogen gas was realized in the RO brine whose complex composition decreased the electrode efficiency, for example from 71.4 ± 0.2%-49.4 ± 0.3 % with the Cu/Zn cathode after 5 cycles of operation.
Magnesium was recovered at the same time of nitrate removal and the purity of Mg(II) could reach 96.8 ± 2.0 % after proper pH pre-treatment. In a preliminary adsorption study, a key byproduct – chlorate was reduced by 49.8 ± 2.7 % after 3-h adsorption by 100 g L-1 activated carbon.
These results have demonstrated the simultaneous electrochemical nitrate removal and resource recovery from a complex water like a RO brine and provided new information such as byproduct management and electrode deterioration.

Determination of volatile phenols in red wines by dispersive liquid-liquid microextraction and gas chromatography-mass spectrometry detection.

A new method was developed for analysing 4-ethylguaiacol and 4-ethylphenol in the aroma of red wines using dispersive liquid-liquid microextraction (DLLME) coupled with gas chromatography-mass spectrometry detection (GC-MS).
Parameters such as extraction solvent, sample volume and disperser solvent were studied and optimised to obtain the best extraction results with the minimum interference from other substances, thus giving clean chromatograms. The response linearity was studied in the usual concentration ranges of analytes in wines (50-1500 microg/L). Repeatability and reproducibility of this method were lower than 5% for both volatile phenols.
Limits of detection and limits of quantification were also determined, and the values found were 28 and 95 microg/L for 4-ethylguaiacol and 44 and 147 microg/L for 4-ethylphenol, respectively.
This new method has been used for the determination of the volatile phenols concentration in different samples of Tannat wine affected by Brettanomyces contamination.

High-performance liquid chromatography method development and validation for simultaneous determination of five model compounds, antipyrine, metoprolol, ketoprofen, furosemide and phenol red, as a tool for the standardization of rat in situ intestinal permeability studies using timed wavelength detection.

A simple, precise, accurate and rugged reversed-phase high-performance liquid chromatography (HPLC) method has been developed and validated for the simultaneous determination of five permeability model compounds, viz. antipyrine, metoprolol, ketoprofen, furosemide and phenol red.
The method was intended to standardize rat in situ single-pass intestinal perfusion studies to assess the intestinal permeability of drugs in the market as well as new chemical entities. Optimum resolution was achieved by gradient elution on a Symmetry Shield C-18 analytical column with the mobile phase consisting of a mixture of aqueous potassium dihydrogen orthophosphate (pH 5.5; 0.01 m) and methanol at a flow rate of 1.5 mL/min.
The retention times of antipyrine, metoprolol, ketoprofen, phenol red and furosemide were about 9, 12, 13, 16 and 17 min, respectively. Data acquisition was carried out using a photo diode array detector in the wavelength range 210-600 nm. Extraction of chromatograms was carried out by timed wavelength.
Data obtained in all studies indicated that the method was suitable for the intended purpose. The validated method was found to be linear and precise in the working range. Suitability of storage under various conditions and freeze/thaw impact at cold temperature were established to ensure complete sample recovery without any stability issues. Recovery very close to the spiked amounts indicated that the method was highly accurate and suitable for use on routine basis.

A simple and rapid high-performance liquid chromatography method for determining furosemide, hydrochlorothiazide, and phenol red: applicability to intestinal permeability studies.

A simple reversed-phase high-performance liquid chromatography (HPLC) method with ultraviolet detection at 280 nm was developed for simultaneous quantitation of furosemide and hydrochlorothiazide along with phenol red as a nonabsorbable marker for in situ permeability studies in anaesthetized rats.
A jejunal segment of approximately 10 cm was isolated and cannulated in both ends for inlet and outlet solution. The perfusate was collected every 10 min, and samples were analyzed using the developed method.
The mobile phase was acetonitrile-water-triethylamine-glacial acetic acid (41.5 + 57.4 + 0.1 + 0.9, adjusted to pH 5.6) at a flow rate of 1 mL/min; the run time was 9 min. The calibration graphs were linear for all 3 compounds (r>> 0.999) across the concentration range of 7.93-125 microg/mL for phenol red and 6.25-100 microg/mL for hydrochlorothiazide and furosemide.
The limits of quantitation were 7.2, 8.9, and 6.8 microg/mL for furosemide, hydrochlorothiazide, and phenol red, respectively. The coefficients of variation for intraassay and interassay precision were less than or equal to 7.6%, and the accuracy was between 93.2-103.4%. Using the single pass intestinal perfusion technique and the suggested HPLC method for sample analysis, mean values of 0.25 x 10(-4) (+/-0.16) cm/s and 0.22 x 10(-4) (+/-0.13) cm/s were obtained for furosemide and hydrochlorothiazide, respectively.

Construction of a colorimetric sensor array based on the coupling reaction to identify phenols

Phenols are harmful to the human body and the environment. Since there are a variety of phenols in actual samples, this requires a sensor which possesses the ability to simultaneously distinguish them. Herein, we report a colorimetric sensor array, which uses two nanozymes (Fe-N-C nanozymes and Cu-N-C nanozymes) as electronic tongues for fingerprint identification of six phenols (2,4,6-trichlorophenol (2,4,6-Tri), 4-nitrophenol (P-np), phenol (Phe), 3-chlorophenol (3-CP), 4-chlorophenol (4-CP), and o-nitrophenol (O-np)) in the environment.
Nanozymes catalyzed the reaction of hydrogen peroxide, different phenols and 4-aminoantipyrine (4-AAP) to produce different color variations. These signal changes as fingerprints encouraged us to develop a pattern recognition method for the identification of phenols by linear discriminant analysis (LDA). The six phenols at 50 nM have their own response patterns, respectively. Surprisingly, this sensor array had distinguished the six phenols in actual samples successfully.

Ultrafast Proton-Transfer Reaction in Phenol-(Ammonia) n Clusters: An Ab Initio Molecular Dynamics Investigation

The ability of phenol to transfer a proton to surrounding ammonia molecules in a phenol-(ammonia)n cluster depends on the relative orientation of ammonia molecules, and a critical field of about 285 MV cm-1 is essential along the O-H bond for the proton-transfer process. Ab initio MD simulations reveal that the proton-transfer process from phenol to ammonia cluster is spontaneous when the cluster has at least eight ammonia molecules, and the proton-transfer event is almost instantaneous (about 20-120 fs).
These simulations also reveal that the rate-determining step for the proton-transfer process is the reorganization of the solvent around the OH group.
During the solvent reorganization process, the fluctuations in the solvent occur until a particular set of configurations projects the field in excess of the critical electric field along the O-H bond which drives the proton-transfer process. Further, the proton-transfer process follows a curvilinear path which includes the O-H bond elongation and out-of-plane movement of the proton and can be referred to as a “bend-to-break” process.

Inhibition studies of bacterial α-carbonic anhydrases with phenols

The α-class carbonic anhydrases (CAs, EC 4.2.1.1) from the bacterial pathogens Neisseria gonorrhoeae (NgCAα) and Vibrio cholerae (VchCAα) were investigated for their inhibition by a panel of phenols and phenolic acids. Mono-, di- and tri-substituted phenols incorporating additional hydroxyl/hydroxymethyl, amino, acetamido, carboxyl, halogeno and carboxyethenyl moieties were included in the study.

Phenol red

from Bio Basic
PB0420 | 25g: 70.88 EUR

Phenol Red

from Glentham Life Sciences
GT9844-100G | 100 g: 110.00 EUR

Phenol Red

from Glentham Life Sciences
GT9844-250G | 250 g: 181.00 EUR

Phenol Red

from Glentham Life Sciences
GT9844-25G | 25 g: 62.00 EUR

Phenol Red

from Glentham Life Sciences
GT9844-5G | 5 g: 46.00 EUR

Phenol Red Solution

from GenDepot
CA013-010 | 100ml: 69.00 EUR

Phenol-liquid, saturated with water

from Bio Basic
PC5523 | 100ml: 91.76 EUR

Phenol red, sodium salt

from Bio Basic
PD0424 | 25g: 63.92 EUR

Phenol Red (sodium salt)

from MedChemExpress
HY-D0169A | 500mg: 108.00 EUR

Phenol Red sodium salt

from Glentham Life Sciences
GT6682-100G | 100 g: 142.00 EUR

Phenol Red sodium salt

from Glentham Life Sciences
GT6682-25G | 25 g: 70.00 EUR

Phenol Red sodium salt

from Glentham Life Sciences
GT6682-5G | 5 g: 44.00 EUR

Ceraplex , No Phenol red

from GenDepot
C3320-050 | 500ml: Ask for price

PHENOL RED BROTH BASE

from Alphabiosciences
P16-104-10kg | 10 kg: 899.00 EUR

PHENOL RED BROTH BASE

from Alphabiosciences
P16-104-2kg | 2kg: 234.00 EUR

PHENOL RED BROTH BASE

from Alphabiosciences
P16-104-500g | 500 g: 100.00 EUR

PHENOL RED DEXTROSE BROTH

from Alphabiosciences
P16-105-10kg | 10 kg: 743.00 EUR

PHENOL RED DEXTROSE BROTH

from Alphabiosciences
P16-105-2Kg | 2 Kg: 200.00 EUR

PHENOL RED DEXTROSE BROTH

from Alphabiosciences
P16-105-500g | 500 g: 90.00 EUR

PHENOL RED LACTOSE BROTH

from Alphabiosciences
P16-121-10kg | 10 kg: 1254.00 EUR

PHENOL RED LACTOSE BROTH

from Alphabiosciences
P16-121-2Kg | 2 Kg: 312.00 EUR

PHENOL RED LACTOSE BROTH

from Alphabiosciences
P16-121-500g | 500 g: 121.00 EUR
The best NgCAα inhibitrs were phenol, 3-aminophenol, 4-hydroxy-benzylalcohol, 3-amino-4-chlorophenol and paracetamol, with KI values of 0.6-1.7 µM. The most effective VchCAα inhibitrs were phenol, 3-amino-4-chlorophenol and 4-hydroxy-benzyl-alcohol, with KI values of 0.7-1.2 µM. Small changes in the phenol scaffold led to drastic effects on the bacterial CA inhibitory activity. This class of underinvestigated bacterial CA inhibitors may thus lead to effective compounds for fighting drug resistant bacteria.