The small molecule Erk1/2 signaling pathway inhibitor PD98059 improves DNA repair in an experimental autoimmune encephalomyelitis SJL/J mouse model of multiple sclerosis.

Multiple sclerosis (MS) is a demyelinating disorder in which the myelin sheath covering the central nervous system axons is damaged or lost, disrupting action potential conduction and leading to various neurological complications. The pathogenesis of MS remains unclear, and no effective therapies are currently available. MS is triggered by environmental factors in genetically susceptible individuals. DNA damage and DNA repair failure have been proposed as MS genetic risk factors; however, inconsistent evidence has been found in multiple studies. Therefore, more investigations are needed to ascertain whether DNA damage/repair is altered in this disorder. In this context, therapies that prevent DNA damage or enhance DNA repair could be effective strategies for MS treatment. The overactivation of the extracellular-signal-related kinase 1 and 2 (Erk1/2) pathway can lead to DNA damage and has been linked to MS pathogenesis. In our study, we observed substantially elevated oxidative DNA damage and slower DNA repair rates in an experimentally autoimmune encephalomyelitis animal model of MS (EAE). Moreover, statistical decreases in oxidative DNA strand breaks and faster repair rates were observed in EAE animals injected with the Erk1/2 inhibitor PD98059 (PD). Moreover, the expression of several genes associated with DNA strand breaks and repair changed in EAE mice at both the mRNA and protein levels, as revealed by the RT2 Profiler PCR array and verified by RT-PCR and protein analyses. The treatment with PD mitigated these changes and improved DNA repair gene expression. Our results demonstrate clear associations between Erk1/2 activation, DNA damage/repair, and MS pathology, and further suggest that PD therapy may be a promising adjuvant therapeutic strategy.

Emerging advances and current applications of nanoMOF-based membranes for water treatment.

Metal-organic frameworks (MOFs) are significantly tunable materials that can be exploited in a wide range of applications. In recent years, a large number of studies have been focused on synthesizing nano-scale MOFs (nanoMOFs), thus taking advantage of these unique materials in various applications, especially those that are only possible at nano-scale. One of the technologies where nanoMOF materials occupy a central role is the membrane technology as one of the most efficient separation techniques. Therefore, numerous reports can be found on the enhancement of the physicochemical properties of polymeric membranes by using nanoMOFs, leading to remarkably improved performance. One of the most considerable applications of these nanoMOF-based membranes is in water treatment systems, because freshwater scarcity is now an undeniable crisis facing humanity. In this in-depth review, the most prominent synthesis and post-synthesis methods for the fabrication of nanoMOFs are initially discussed. Afterwards, different nanoMOF-based composite membranes such as thin-film nanocomposites (TFN) and mixed-matrix membranes (MMM) and their various fabrication methods are reviewed and compared. Then, the impacts of using MOFs-based membranes for water purification through growing metal-organic frameworks crystals on the support materials and utilization of metal-organic frameworks as fillers in mixed matrix membrane (MMM) are highlighted. Finally, a summary of pros and cons of using nanoMOFs in membrane technology for water treatment purposes and clear future prospects and research potentials are presented.

Validation of a novel UPLC-MS/MS method for estimation of metformin and empagliflozin simultaneously in human plasma using freezing lipid precipitation approach and its application to pharmacokinetic study.

A fast, sensitive one step UPLC ESI-MS/MS method was successfully applied for the simultaneous estimation of two concurrently administrated antidiabetic drugs, Metformin (MET) and Empagliflozin (EMPA) in human plasma. Metformin-d6 (MET-d6) and Empagliflozin-d4 (EMPA-d4) were utilized as internal standards. Extraction of the analytes from the human plasma was performed through acetonitrile precipitation technique followed by freezing the precipitated plasma proteins and lipids to minimize the matrix effect. Chromatographic analysis was developed on Acquity UPLC BEH C18 column (1.7 µm, 2.1 × 50 mm) using isocratic elution mode. A mobile phase of formic acid (0.01 %): acetonitrile (70:30 v/v) with a flow rate of 0.3 mL/min achieved optimum separation. Multiple reaction monitoring (MRM) in positive ion mode, with transitions at (m/z) 130.14 →71.08 for (MET), 451.72 →71.29 for (EMPA), 136.03 →77.02 for (MET-d6), and 455.43 → 75.05 for (EMPA-d4) was used for quantification. The obtained linearity covered the concentration ranges of 10-1500 ng/mL and 2.0-250.0 ng/mL for MET and EMPA, respectively. The run time of the proposed Method didn't exceed 3.0 min allowing faster analysis and determination of larger number of samples per day without affecting accuracy and sensitivity. The presented chromatographic method could be successfully applied in pharmacokinetics studies and therapeutic monitoring of MET and EMPA in patients' plasma administrating fixed dose combination of both drug with high reproducibility and ruggedness.

pH assists simultaneous determination of folic acid and vitamin D3 in biological fluids using a novel Tb3+-acyclovir optical biosensor.

An innovative, simple and cost effective Tb3+-acyclovir photo probe was designed and used as a core for a spectrofluorometric approach to sensitively determine two vital biological compounds in different matrices. The Tb3+-acyclovir complex displays a characteristic electrical band with λ em at 545 nm with significant luminescence intensity, which is quenched in the presence of folic acid and vitamin D3 at pH 5.0 and 9.0, respectively. The conditions were optimized and the best solvent for operation was found to be acetonitrile and λ ex at 340 nm. folic acid was successfully estimated in tablet dosage form, urine and serum in the concentration range of 2.28 × 10-6 to 1.49 × 10-9 mol L-1. Vitamin D3 was also assessed in serum samples using the same optimal conditions within the concentration range of 3.2 × 10-9 to 1.0 × 10-6 mol L -1. The proposed luminescence method was validated in accordance with ICH guidelines and found to be accurate, precise and specific and free from any interferences. The cost effectiveness and applicability of the method make it a good choice for routine analysis of the two compounds and early diagnosis of chronic diseases associated with abnormalities in their physiological levels.

Highly Selective Optical Sensor Eu (TTA)3 Phen Embedded in Poly Methylmethacrylate for Assessment of Total Prostate Specific Antigen Tumor Marker in Male Serum Suffering Prostate Diseases.

A low-cost, simple, and highly selective method was used for the assessment of total prostate specific antigen (tPSA) in the serum of prostate cancer patients. This method is based on quenching the intensity of luminescence displayed by the optical sensor Eu (TTA)3 phen/poly methylmethacrylate (PMMA) thin membrane or film upon adding different concentrations of tPSA. The luminescent optical sensor was synthesized and characterized through absorption, emission, scanning electron microscopy (SEM), and x-ray diffraction (XRD), and is tailored to present red luminescence at 614 nm upon excitation at 395 nm in water. The fabricated sensor fluorescence intensity is quenched in the presence of tPSA in aqueous media. The fluorescence resonance energy transfer (FRET) is the main mechanism by which the sensor performs. The sensor was successfully utilized to estimate tPSA in the serum of patients suffering prostate cancer in a time and cost effective way. The statistical results of the method were satisfactory with 0.0469 ng mL-1 as a detection limit and 0.99 as a correlation coefficient.

Phthalocyanine-doped polystyrene fluorescent nanocomposite as a highly selective biosensor for quantitative determination of cancer antigen 125.

A novel, simple, sensitive, and precise spectrofluorometric assay of cancer antigen [CA 125] is described. This modality is based on monitoring the quenching of the luminescence intensity at 790 nm of the phthalocyanine fluorophore, in a nanocomposite comprising the fluorophore and cationic polystyrene, which results from interaction with CA 125. The remarkable quenching of the luminescence intensity of the Ni-phthalocyanine complex doped in PS matrix by various concentrations of CA 125 was successfully utilized as an optical sensor for the determination of CA 125 in different serum samples of ovarian disease. The performance of the designed biosensor is determined through monitoring the quenching of the luminescence intensity at 790 nm by cancer antigen 125 after excitation at 685 nm, pH 7.3 in water. The calibration plot was achieved over the concentration range 1.0 × 10-2 - 127 U mL-1 CA-125 with a correlation coefficient of 0.99 and detection limit of 1.0 × 10-4 U mL-1. The mechanism of the interaction between the nano thin film nickel(II)phthalocyanine and CA-125 was discussed. A significant correlation between the proposed method for the assessment of CA 125 and the standard method was applied to patients and controls.

Assessment of DNA repair efficiency in the inbred BTBR T+tf/J autism spectrum disorder mouse model exposed to gamma rays and treated with JNJ7777120.

Information regarding DNA repair in autism is limited to a few studies, which have reported inconsistent results. Therefore, we designed a study to determine whether DNA repair efficiency is altered in autism and to investigate whether the H4 ligand JNJ7777120 can enhance DNA repair efficiency in BTBR T+tf/J (BTBR) mice; we also attempted to elucidate the mechanism(s) underlying this amelioration. Evaluation of DNA damage using the comet assay on bone marrow cells showed increased levels of DNA damage in BTBR mice compared with age-matched control C57BL/6J mice. Conversely, BTBR animals pretreated with 20 mg/kg JNJ7777120 for five days exhibited significant decreases in DNA damage compared with that of control BTBR mice. Our results also indicated higher sensitivity of BTBR mice exposed to gamma rays to DNA damage generation. A marked difference was observed between BTBR and C57BL/6J mice at different sampling times after irradiation, with BTBR mice showing a higher percentage of DNA damage and slower repair rate than that of C57BL/6J mice. JNJ7777120 led to enhanced repair of the DNA damage induced by radiation when administered to BTBR mice five days prior to radiation. Additionally, oxidative stress in BTBR mice was significantly elevated with a reduced GSH/GSSG ratio; significant amelioration was subsequently observed in JNJ7777120-pretreated BTBR mice. Furthermore, repetitive behaviors were also attenuated in BTBR mice by JNJ7777120 treatment without altering locomotor activity. Our results suggest that JNJ7777120 can be developed for use as a therapeutic agent to enhance DNA repair efficiency in autism spectrum disorder.

Determination of uric acid in serum using an optical sensor based on binuclear Pd(II) 2-pyrazinecarboxamide-bipyridine doped in a sol gel matrix.

A new highly green luminescent binuclear palladium 2-pyrazinecarboxamide-bipyridine complex [Pd(pyc)(bpy)] was prepared and characterized. The binuclear Pd(pyc)(bpy) complex doped in sol-gel matrix has a strong luminescence intensity at 547 nm with λex = 330 nm in water The method depends on the quenching of the luminescence intensity of the binuclear Pd(pyc)(bpy) complex at 547 nm by different concentrations of uric acid. The remarkable quenching of the luminescence intensity of the binuclear Pd(pyc)(bpy) complex, doped in a sol-gel matrix, by uric acid was successfully used for the determination of uric acid in serum samples of patients with hypouricemia disease. The calibration plot was achieved over the concentration 3.9 × 10-9 to 1.2 × 10-4 mol L-1uric acid with a correlation coefficient of 0.9 and a detection limit of 1.8 × 10-10 mol L-1. The method was used satisfactorily for the assessment of the uric acid in a number of serum samples collected from various patients with Hypouricemia disease.

Alpha fetoprotein assessment by using a nano optical sensor thin film binuclear Pt-2-aminobenzimidazole-Bipyridine for early diagnosis of liver cancer.

A simple, precise and sensitive method in which, a nano optical sensor binuclear Pt-2-aminobenzimidazole-bipyridine, Pt(abi)(bpy) complex doped in sol gel is used for the early diagnosis of liver cancer. The idea depends on the assessment of the concentration of alpha fetoprotein (AFP) in the serum samples of different liver patients. The nano binuclear Pt(abi)(bpy) has strong emission spectrum upon excitation at 380 nm in distilled water. The assessment of alpha fetoprotein (AFP) depends on the quenching of the emission spectrum of the optical sensor at 610 nm in water by the alpha fetoprotein (AFP). The calibration plot was achieved over the concentration 5.0 - 350 U L-1 with a correlation coefficient of 0.997 and a detection limit of 3.0 U L-1. The method was used satisfactorily for the diagnosis of liver cancer in a number of serum samples collected from various patients and health state; healthy (≤ 30 U L-1), Virus B (42.2-69.5 U L-1), Virus C (75.7-98.4 U L-1), Cirrhosis (112-147 U L-1) and HCC (185.2-349.6 U L-1). Furthermore, the assessment of the alpha-fetoprotein by the proposed method increases its sensitivity (92.88%) and specificity (91.41%) for early diagnosis of HCC.

Lanthanide complexes of spiropyran photoswitch and sensor: spectroscopic investigations and computational modelling.

A number of novel lanthanide (Gd3+, Sm3+, and Tb3+) complexes of the 1',3'-dihydro-8-methoxy-1',3',3'-trimethyl-6-nitrospiro[2H-1-benzopyran-2,2'-(2H)-indole] (spiropyran; SP), a widely studied molecular photoswitch, were investigated. Comparative spectroscopic (absorption and fluorescence) and kinetic investigations of the stimulated photochromic and solvatochromic behavior were carried out in different media. SP embedded in a rigid thin film of poly(methylmethacrylate) might be exploited profitably as an optical sensor for the identification of a solvent's nature. Furthermore, thermodynamic parameters, in particular, Gibbs' free energy change (ΔG°), were derived using density functional theory quantum chemical calculations with the SP and merocyanine coloured form. The model used was the B3LYP/6-31G(d,p)/SCRF = (SMD, solvent) and its time-dependent extension procedure was used to quantitatively explain the structural isomerization in response to a variety of stimuli, such as light, solvent nature, lanthanide(iii) ions, and macromolecular support. These findings might be useful for the design of photoswitchable and energy transfer materials and their related fields.

Ultra-Sensitive Nano Optical Sensor Samarium-Doxycycline Doped in Sol Gel Matrix for Assessment of Glucose Oxidase Activity in Diabetics Disease.

A low cost and very sensitive method for the determination of the activity of glucose oxidase enzyme in different diabetics serum samples was developed. The method based on the assessment of the H2O2 concentration produced from the reaction of the glucose oxidase (GOx) enzyme with glucose as substrate in the serum of diabetics patients by nano optical sensor Sm-doxycycline doped in sol gel matrix. H2O2 enhances the luminescence intensity of all bands of the nano Sm-doxycycline complex [Sm-(DC)2]+ doped in sol-gel matrix, especially the 645 nm band at λex = 400 nm and pH 7.0 in water. The influence of the different analytical parameters that affect the luminescence intensity of the nano optical sensor, e.g. pH, H2O2 concentration and foreign ions concentrations were studied. The remarkable enhancement of the luminescence intensity of nano optical sensor [Sm-(DC)2]+ complex in water at 645 nm by the addition of various concentrations of H2O2 was successfully used as an optical sensor for the assessment of the activity of the glucose oxidase enzyme in different diabetics serum samples. The calibration plot was achieved over the activity range 0.1-240 U/L with a correlation coefficient of 0.999 and a detection limit of 0.05 U/L.

Nano optical probe samarium tetracycline complex for early diagnosis of histidinemia in new born children.

A new, precise, and very selective method for increasing the impact and assessment of histidine as a biomarker for early diagnosis of histidinemia disease in new born children was developed. The method depends on the formation of the ion pair associate between histidine and the nano optical samarium tetracycline [Sm-(TC)2]+ complex doped in sol-gel matrix in a borate buffer of pH 9.2. The [Sm-(TC)2]+ complex has +I net charge which is very selective and sensitive for [histidine]- at pH 9.2 in serum and urine samples of histidinemia disease. Histidine enhances the luminescence intensity of the nano optical [Sm-(TC)2]+ complex at 645nm after excitation at 400nm, in borate buffer, pH 9.2. The remarkable enhancement of the luminescence intensity at 645nm of nano [Sm-(TC)2]+ complex doped in sol-gel matrix by various concentrations of the histidine was successfully used as an optical probe for the assessment of histidine in different serum and urine samples of new born children infected by histidinemia. The calibration plot was achieved over the concentration range 1.4×10-5 - 6.5×10-10molL-1 histidine with a correlation coefficient of (0.998) and a detection limit of (3.2×10-10molL-1). The sensitivity (98.88%) and specificity (97.41%) of histidine as a biomarker were calculated.

Progress of pancreatitis disease biomarker alpha amylase enzyme by new nano optical sensor.

A new nano optical sensor binuclear Pd-(2-aminothiazole) (urea), Pd(atz,ur) complex was prepared and characterized for the assessment of the activity of alpha amylase enzyme in urine and serum samples for early diagnosis of Pancreatitis disease. The assessment of alpha amylase activity is carried out by the quenching of the luminescence intensity of the nano optical sensor binuclear Pd(atz,ur) complex at 457nm by the 2-chloro-4-nitrophenol (2-CNP) which produced from the reaction of the enzyme with 2-chloro-4-nitrophenyl-α-d-maltotrioside (CNPG3) substrate. The remarkable quenching of the luminescence intensity at 457nm of nano Pd(atz,ur) doped in sol-gel matrix by various concentrations of the 2-CNP was successfully used as an optical sensor for the assessment of α-amylase activity. The calibration plot was achieved over the concentration range 8.5×10(-6) to 1.9×10(-9)molL(-1) 2-CNP with a correlation coefficient of (0.999) and a detection limit of (7.4×10(-10)molL(-1)). The method was used satisfactorily for the assessment of the α-amylase activity over activity range (3-321U/L) in different urine and serum samples of pancreatitis patients. The assessment of the alpha amylase biomarker by the proposed method increases its sensitivity (96.88%) and specificity (94.41%) for early diagnosis of pancreatitis diseases.

Nano optical sensor binuclear Pt-2-pyrazinecarboxylic acid -bipyridine for enhancement of the efficiency of 3-nitrotyrosine biomarker for early diagnosis of liver cirrhosis with minimal hepatic encephalopathy.

A new, precise, and very selective method for increasing the impact and assessment of 3-nitrotyrosine (3-Nty) as a biomarker for early diagnosis of liver cirrhosis with minimal hepatic encephalopathy (MHE) disease was developed. The method depends on the formation of the ion pair associate between 3-nitrotyrosine and the optical sensor binuclear Pt-2-pyrazinecarboxylic acid (pca)-Bipyridine (bpy) complex doped in sol-gel matrix in buffer solution of pH 7.3. The binuclear Pt (pca)(bpy) has +II net charge which is very selective and sensitive for [3-Nty](-2) at pH 7.3 in serum sample of liver cirrhosis with MHE diseases. 3-nitrotyrosine (3-Nty) quenches the luminescence intensity of the nano optical sensor binuclear Pt(pca) (bpy) at 528nm after excitation at 370nm, pH 7.3. The remarkable quenching of the luminescence intensity at 528nm of nano binuclear Pt(pca) (bpy) doped in sol-gel matrix by various concentrations of the 3-Nty was successfully used as an optical sensor for the assessment of 3-Nty in different serum samples of (MHE) in patients with liver cirrhosis. The calibration plot was achieved over the concentration range 1.85×10(-5) - 7.95×10(-10)molL(-1) 3-Nty with a correlation coefficient of (0.999) and a detection limit of (4.7×10(-10)molL(-1)). The method increases the sensitivity (93.75%) and specificity (96.45%) of 3-Nty as a biomarker for early diagnosis of liver cirrhosis with MHE in patients.

Inkjet printable luminescent Eu3+-TiO2 doped in sol gel matrix for paper tagging.

Europium (III) with different concentrations (0.2, 0.4 and 0.8 %)-TiO(2) doped silica composite systems were sensitized by sol-gel method. Different spectroscopic and microscopic tools characterized the composites. The Europium ion incorporated into the liquid silica-titania solution acts as red light emission center in the luminescent materials. This luminescent nano composite pigment has great potential of application in preparing luminescent ink. Inkjet printer loaded with the prepared ink to show its potential usage as tagging material performed the printing test on a white paper.

Durable diagnosis of seminal vesicle and sexual gland diseases using the nano optical sensor thin film Sm-doxycycline complex.

A new method in which a nano optical sensor for diagnosis of different diseases of seminal vesicle and sexual gland was prepared. The working principle of the method depends on the determination of the fructose concentration in semen of different patients by using nano optical sensor thin film Sm-doxycycline doped in sol-gel matrix. The assay is based on the quenching of the characteristic emission bands of Sm(3+) present in silica doped Sm-doxycycline nanooptode thin film by different fructose concentrations in acetonitrile at λex = 400 nm. This method was optimized for parameters, such as, solvent effect, operational stability, shelf life and interference parameters. Good and reproducible linearity (1 × 10(-9) - 5.0 × 10(-5) mol L(-1)) with a detection limit of 9.0 × 10(-10) mol L(-1) and quantification limit of detection (LOQ) 2.7 × 10(-9) mol L(-1) were obtained. Seminal fructose determination in different patient samples after appropriate dilutions confirmed the reliability of this technique. The method was successfully applied for routine fructose monitoring in human semen samples of different cases such as; obstructive and non-obstructive azoospermia, inflammation of male accessory glands, atrophy of seminal vesicle, congenital vas deferens and retrograde ejaculation.

Uranyl ions adsorption by novel metal hydroxides loaded Amberlite IR120.

In this work, Ni(OH)2-loaded Amberlite IR120 (Ni-MA) and Co(OH)2-loaded Amberlite IR120 (Co-MA) resins were prepared, characterized and applied for UO2(2+) removal from aqueous solutions. The adsorption characteristics were investigated in a batch system with respect to effect of contact time, pH, equilibrium isotherms and removal kinetics data. The results indicated that the UO2(2+) could be efficiently removed from aqueous solutions at pH = 3.5 using Ni-MA and Co-MA resins. The maximum adsorption capacities for the UO2(2+) of Ni-MA and Co-MA were found to be 439 mg/g and 451 mg/g respectively. The equilibrium data fit well with the Langmuir adsorption isotherm. Kinetics study showed that the adsorption process was fast and reached equilibrium within 60 min and the kinetics data fit well with pseudo-second order and intra-particle diffusion models for both resins. The adsorption mechanism has been proposed and discussed. It was found that both Ni-MA and Co-MA resins could be used effectively for UO2(2+) removal from aqueous solutions.

Synthesis and characterization of new light emitter symmetrical phenoxazinium salt and its potential application as sensor for assessment of Hg2+.

The sensitization of the excited triplet state of a novel symmetrical Bis(dialkylamino)phenoxazinium salt was developed in the presence of Hg(2+). This effect was used to determine the concentration of Hg(2+) in different water samples. The phenoxazinium salt sensor was characterized by different spectroscopic tools such as: UV, FTIR, NMR and fluorescence spectra. The sensor has an emission band at 347 nm in DMSO. Hg(2+) in DMSO at pH 5.6 can remarkably quench the fluorescence intensity of the sensor at 347 nm and a new band was appeared at 436 nm due to the strong complex formation between Hg(2+) and sensor. The quenching of the band intensity at 347 and the enhancement of the intensity of the new band at 436 were used to determine the Hg(2+) in different waste water samples. The dynamic range found for the determination of Hg(2+) concentration is 8.7 × 10(-10) - 1.4 × 10(-6) mol L(-1) with a detection limit of 5.8 × 10(-10) mol L(-1) and quantification detection limit of 1.8 × 10(-9) mol L(-1).

A new nano-optical sensor thin film cadmium sulfide doped in sol-gel matrix for assessment of α-amylase activity in human saliva.

A novel, simple, sensitive and precise spectrofluorimetric method is developed for measuring the activity of the α-amylase enzyme in human saliva. The remarkable quenching of the luminescence intensity at 634 nm of nano CdS doped in a sol-gel matrix by various concentrations of maltose (produced from the reaction of the enzyme with the starch substrate) was successfully used as an optical sensor for the assessment of α-amylase activity. The calibration plot was achieved over the concentration range 4.8 × 10(-10) to 1.2 × 10(-5) mol L(-1) maltose with a correlation coefficient of 0.999 and a detection limit of 5.7 × 10(-11) mol L(-1). The method was used satisfactorily for assessment of the α-amylase activity in a number of human saliva samples collected from various healthy volunteers.

A Novel Method for the Assessment of Cortisol Hormone in Different Body Fluids Using A New Photo Probe Thiazole Derivative.

A low cost and accurate method for the detection and analytical determination of the cortisol in pharmaceutical preparation, blood serum and urine was developed. The method was based upon the enhancement of fluorescence intensity of the band at 424 nm of the photo probe by different cortisol concentrations in acetonitrile at (pH 5.7, λex = 320 nm). The influence of the different parameters, e.g. pH, solvent, cortisol concentration and foreign ions concentrations that control the enhancement process of fluorescence intensity of the band of photo probe was critically investigated. The remarkable enhancement of the fluorescence intensity at 424 nm in acetonitrile by various concentrations of cortisol was successfully used as a photo- probe for the assessment of cortisol concentration. The calibration plot was achieved over the concentration range 8.0 × 10(-6)-5.5 × 10(-9) mol L(-1) cortisol with a correlation coefficient of 0.998 and a detection limit of 4.7 × 10(-9) mol L(-1). The developed method is simple and proceeds without practical artifacts compared to the other determination methods.