Spectrochemical Techniques Research Articles

Deepening the Understanding of Carbon Active Sites for ORR Using Electrochemical and Spectrochemical Techniques.

Defect-containing carbon nanotube materials were prepared by subjecting two commercial multiwalled carbon nanotubes (MWCNTs) of different purities to purification (HCl) and oxidative conditions (HNO3) and further heat treatment to remove surface oxygen groups. The as-prepared carbon materials were physicochemically characterized to observe changes in their properties after the different treatments. TEM microscopy shows morphological modifications in the MWCNTs after the treatments such as broken walls and carbon defects including topological defects. This leads to both higher surface areas and active sites. The carbon defects were analysed by Raman spectroscopy, but the active surface area (ASA) and the electrochemical active surface area (EASA) values showed that not all the defects are equally active for oxygen reduction reactions (ORRs). This suggests the importance of calculating either ASA or EASA in carbon materials with different structures to determine the activity of these defects. The as-prepared defect-containing multiwalled carbon nanotubes exhibit good catalytic performance due to the formation of carbon defects active for ORR such as edge sites and topological defects. Moreover, they exhibit good stability and methanol tolerances. The as-prepared MWCNTs sample with the highest purity is a promising defective carbon material for ORR because its activity is only related to high concentrations of active carbon defects including edge sites and topological defects.

Development of cancer-targeted nano gold functionalized ruthenium(III)-doxorubicin complex: Synthesis, characterization and evaluation of DNA cleavage, anticancer and bioimaging activity

Metal-based drugs have attracted greater attention for cancer diseases because of biological relevance. However, some drawbacks are present in the metal complexes such as low stability and low bioavailability. Nanomaterials functionalized metal complexes can protect the stability and enhanced the bioavailability. In the present study, Nano gold functionalized ruthenium(III) complex from doxorubicin have been synthesized from ruthenium(III) complex and characterized using various spectrochemical techniques such as IR, UV, and NMR. In the metal complex, Doxorubicin (DOX) acts as a monobasic bidentate ligand and is coordinated through the carbonyl oxygen and phenolate oxygen of the anthracene ring. Based on spectral evidences, the complex [Ru(DOX)(PPh3)2Cl2] has an octahedral geometry. The Nano Au-Ru(III) DOX is analysed for their size, and morphology using XRD, SEM and HRTEM. X-ray diffraction pattern revealed that the complex has nanocrystalline in nature. The Nano Au-Ru(III) DOX is spherical shape and particle size is less than 15 nm. The DNA cleavage activity of [Ru(DOX)(PPh3)2Cl2] and Nano Au-Ru(III) DOX has been evaluated using pUC18 plasmid DNA and the results showed significant cleavage. The [Ru(DOX)(PPh3)2Cl2] and Nano Au-Ru(III) DOX have been tested against human breast cancer (MCF-7) and leukemia cancer cell lines (K-562) in vitro for its antitumor effects. The tumour activity of the Nano Au-Ru(III) DOX showed more promising activity than the [Ru(DOX)(PPh3)2Cl2]. The cell imaging of the Nano Au-Ru(III) DOX was examined against epithelial human breast cancer cell line (MDA-MB-231) using fluorescent microscopy. The fluorescence images showed high scattering light in tumour tissue at 100 µg/mL Hence, Nano Au-Ru(III) DOX can serve as a promising drug for cancer therapy and cellular imaging.

Application of spectrochemical analysis with chemometrics to profile biochemical alterations in nanoplastic-exposed HepG2 cells

Humans are routinely exposed to nanoplastics (NPs) in various ways, and this exposure presents a significant health risk. Nevertheless, there remain gaps in our knowledge, particularly in the mechanisms of toxicity of NPs with different surface charges at very low environmental concentrations. Herein, a spectrochemical approach was used to profile the cytotoxicity of NPs with different surface charges in HepG2 cells. It was found that all three NPs can cause some biomolecular alterations in cells, affecting cellular lipids, proteins, amino acids, and genetic material. Of these, PS and PS-COOH led to a non-linear dose-response, which may be related to a biphasic dose-response, whereas PS-NH2 led to a linear dose-response with a gradual increase in toxicity with increasing exposure concentration. In addition, the spectroscopic results showed that surface modifications led to cellular biochemical changes and caused adverse biological effects, with PS-NH2 exhibiting higher toxicity compared to PS or PS-COOH along with an inhibition of cell proliferation. Surprisingly PS-COOH, although considered the least toxic NP, appears to cause DNA damage. Overall, the toxic effects of different surface-modified NPs in cells were detected for the first time by applying spectrochemical techniques, and these findings provide important data towards understanding the emerging widespread environmental pollution of NPs and their effects on humans.

Forensic glass examinations—A review focused on elemental spectrochemical analysis

AbstractGlass is a trace material commonly found at crime scenes that can provide valuable information at early investigative stages and during a trial. The forensic analysis of glass has steadily evolved since the 1970s with numerous technological advances in spectroscopy and spectrometry. This article presents an advanced review of the recent literature concerning the forensic examination of glass evidence and discusses the current state and future opportunities of the discipline. The review focuses on established elemental spectrochemical techniques, including Inductively Coupled Plasma methods (ICP), laser‐ablation, and x‐ray Fluorescence (XRF) methods, and newer applications using Laser Induced Breakdown Spectroscopy (LIBS), Raman Spectroscopy, and accelerator and reactor nuclear techniques. A brief overview of the transfer, persistence, interpretation, and analytical schemes implemented in the field is revised to provide context to the discussion of the capabilities and limitations of the current and emerging technology.This article is categorized under: Forensic Chemistry and Trace Evidence > Trace Evidence

Utilizing laser spectrochemical analytical methods for assessing the ripening progress of tomato

To meet market demands and minimize losses, the tomato crop (Solanum Lycopersicum L.) requires a simple, rapid, and cost-effective method to distinguish between different maturity stages with high accuracy. This study aimed at evaluating two spectrochemical analytical techniques, namely laser-induced fluorescence (LIF) and laser-induced breakdown spectroscopy (LIBS), to discriminate three different maturity stages of tomato fruit (‘Green/Breaker’; ‘Turning/Pink’; and ‘Light-red/Red’). The simple linear regression confirmed the obtained LIF results with chlorophyll content (mg/100 g), hue angle (h°), and firmness (kg/cm2) of the different maturity stages (measured by conventional methods). Furthermore, the findings showed that the peak intensities of LIF spectra decreased with the chlorophyll content depletion during ripening. Moreover, the data exposed a reasonably good association between LIF spectra and chlorophyll content with a regression coefficient of 0.85. On the other hand, firmness and skin hue have shown an excellent predictor for the spectra with a high regression coefficient of 0.94. For LIBS spectra of each maturity stage, the ratios of Ca’s ionic-to-atomic spectral lines intensities have followed the same trend as conventionally measured firmness. The results demonstrated that LIF and LIBS are accurate, easy, and fast techniques used to define tomatoes’ different ripening stages. Both methods are useable in situ without any prior laboratory work.

Raman hyperspectral imaging coupled to three-dimensional discriminant analysis: Classification of meningiomas brain tumour grades

Meningiomas remains a clinical dilemma. They are the commonest “benign” types of brain tumours and, although being typically benign, they are divided into three WHO grades categories (I, II and III) which are associated with the tumour growth rate and likelihood of recurrence. Recurrence depends on extend of surgery as well as histopathological diagnosis. There is a marked variation amongst surgeons in the follow-up arrangements for their patients even within the same unit which has a significant clinical, and financial implication. Knowing the tumour grade rapidly is an important factor to predict surgical outcomes and adequate patient treatment. Clinical follow up sometimes is haphazard and not based on clear evidence. Spectrochemical techniques are a powerful tool for cancer diagnostics. Raman hyperspectral imaging is able to generate spatially-distributed spectrochemical signatures with great sensitivity. Using this technique, 95 brain tissue samples (66 meningiomas WHO grade I, 24 meningiomas WHO grade II and 5 meningiomas that reoccurred) were analysed in order to discriminate grade I and grade II samples. Newly-developed three-dimensional discriminant analysis algorithms were used to process the hyperspectral imaging data in a 3D fashion. Three-dimensional principal component analysis quadratic discriminant analysis (3D-PCA-QDA) was able to distinguish grade I and grade II meningioma samples with 96% test accuracy (100% sensitivity and 95% specificity). This technique is here shown to be a high-throughput, reagent-free, non-destructive, and can give accurate predictive information regarding the meningioma tumour grade, hence, having enormous clinical potential with regards to being developed for intra-operative real-time assessment of disease.

Novel class of precursor-derived Zr–La–B–C(O) based ceramics containing nano-crystalline ultra-high temperature phases stable beyond 1600 °C

In this work, a novel ultra-high temperature resistant precursor-derived ceramic containing Zr, La, B, and C was synthesized through precursor modification of phenol formaldehyde resin. The thermal stability and resistance to crystallization of the ceramic at a temperature of 1600 °C was investigated and was found to be profoundly influenced by the boron content in the starting precursors. The ceramics remained amorphous at 1600 °C for 2 h in argon and upon sustained heat-treatment for up to 16 h resulted in nano-crystalline ultra-high temperature phases such as ZrB 2 , ZrC, LaB 6 and La 2 Zr 2 O 7 . Thermodynamic equilibrium phase calculations show that even longer durations of heat treatment may be required to achieve thermodynamic equilibrium. High-resolution transmission electron microscopy revealed encapsulation of nanocrystals (<5 nm) in an amorphous matrix surrounded by turbostratic layers of carbon inhibiting its growth. Spectrochemical techniques confirmed the presence of boron substituted carbon in the amorphous matrix of the ceramic. The unique nature of the amorphous matrix lends the ceramic resistance to crystallization and chemical degradation that can surpass the likes of classical silicon-based precursor-derived ceramics.

Designing and theoretical study of fluorinated small molecule donor materials for organic solar cells.

A recently synthesized photoactive donor named fluorinated thienyl-substituted benzodithiophene (DRTB-FT), modified with four novel end capped acceptor molecules, has been investigated through different electrical, quantum, and spectrochemical techniques for its enhanced electro-optical and photovoltaic properties. DRTB-FT was connected to 2-methylenemalononitrile (D-1), 2-methylene-3-oxobutanenitrile (D-2), 2-(2-methylene-3-oxo-2,3-dihydro-1H-inden-1-ylidene) malononitrile (D-3), and 3-methyl-5methylene-2-thioxothiazolidin-4-one (D-4) as terminal acceptor moieties. The architectural D-1 and D-3 molecules owe reduced optical band gap of 2.45 and 2.28 eV benefited from A-D-A configuration and have broaden maximum absorption band (λmax) at 617 and 602 nm in polar organic solvent (chloroform). Reduced optical band gap sets the ease for enhanced absorption. Reorganization energy of electron (λe) of D-3 molecule (0.00397 eV) was smaller among all which disclosed its greater mobility of conducting electrons (ICT). Larger values of dipole moment (μ) of D-1 (5.939 Debye) and D-3 (3.661 Debye) molecules in comparison to R indicated greater solubilities of the targeted molecules. Among the tailored molecules, D-3 showed the lowest binding energy of 0.25 eV in solvent phase and 0.08 eV in gaseous phase. The voltaic strength of the designed molecules was examined with respect to fullerene derivative (PC61BM) which exposed that D-1 is the best choice for achieving higher PCE. TDM (transition density matrix), DOS (density of states) analysis, and binding energies all were estimated at MPW1PW91/6-31G (d, p) level of DFT (density functional theory). All the architecture molecules show reduced band gap and high electron transfer rate due to the lowest reorganization energy (RE) of electron. The results show that there is greater contribution of acceptor and conjugated donor core towards the total absorption into the visible region of the spectrum. When tailored molecules D-1, D-2, D-3, and D-4 were blended with fullerene derivative polymer (PC61BM), they give high values of voltage at zero current level (Voc) compared to R.

A greener and cheaper approach towards synthesis of glycerol carbonate from bio waste glycerol using CaO–TiO2 Nanocatalysts

In this work we focused on clean catalytic approach of efficient CaO/TiO2 green nano particles derived from waste chicken eggshells with inorganic support TiO2 for glycerol carbonate synthesis. The designed nano catalysts were characterized using several chemical and spectrochemical techniques like XRD, FE-SEM, TGA-DSC, FT-IR BET-BJH methods. The corelation between the basic strength and catalytic activity of synthesized catalyst was tested by Hammett indicator method and found to be one of the important factors for glycerol carbonate synthesis. Under optimized condition of reaction parameters (Temp- 90 °C, time – 180min, DMC: gly molar ratio 4:1 and catalyst loading 3 wt% of glycerol used in reaction in gram) 3:1 CaO/TiO2 mixed oxide showed an excellent performance of 99.3% glycerol conversion and 93.7% of glycerol carbonate yield. The green metrics like Process mass intensity (PMI), and Environmental factor (E-factor), were well studied and obtained as 1.37 mg and 0.082 respectively for the transesterification process with 100% atom utilization (AU). The designed catalyst possessing ideal green chemistry metrics appreciate the manufacturing process of GLC both in industrial and lab scale. The utilization of waste eggshell not only a cheaper and green catalyst but also reduces the amount of waste and its treatment cost which is economically and ecologically friendly.

Synthesis, Molecular Docking, In Vitro Anti-Bacterial, and Anti-Cancer Activities of Some Novel Oxo-Spiro Chromene Schiff’s Bases

A series of novel oxo-spiro chromene Schiff’s bases were synthesized by condensing 2,7-diamino-2'-oxospiro[chromene-4,3'-indoline]-3-carbonitrile, and series of aromatic aldehydes. Spectrochemical techniques have corroborated the formation of desired products. Derivatives were screened in vitro for antibacterial and anticancer activities. Molecular docking analysis was also performed to predict the possible mode of action of these derivatives. The docking analysis ascertained that these derivatives regulate the antimicrobial potential via inhibition of DNA gyrase and anticancer potential via inhibition of CDK 6. Among all the synthesized compounds, Nitro derivatives have exhibited eminent anticancer and antibacterial activities.

Amperometric determination of hydrazine using a CuS-ordered mesoporous carbon electrode.

Anelectrocatalytic sensor for hydrazine using copper sulfide-ordered mesoporous carbon (CuS-OMC) isdescribed. A facile solvothermal synthetic strategy was adopted for CuS-OMC and the ordered mesoporous carbon was obtained through nanocasting method. The synthesized CuS-OMC was characterized using microscopic and spectrochemical techniques. CuS-OMC was immobilized on GCE and evaluated for its electrochemical sensing of hydrazine using cyclic voltammetry and amperometry. CuS-OMC modified GCE exhibited better hydrazine sensing at an optimized pH7.4 in terms of oxidation potential and current compared with that of GCE, CuS, and OMC. The observed sensing performance of CuS-OMC was attributed to the presence of Cu (I/II) in CuS dispersed in OMC which acts as an electrocatalytic center for the sensing of hydrazine. Amperometry under optimized experimental condition with an applied potential of 270mV was employed to obtain a linear calibration plot in the range 0.25 to 40μM (R2 = 0.9908) with a detection limit of 0.10μM with a sensitivity of 0.915 (± 0.02) μA cm-2μM-1. Real sample analyses were carried out by spiking of hydrazine in differentwater samples and the recoveries were in the range of 97 ± 2.1% (n = 3). Graphical abstract.

Cobalt (II) complex catalyzed polymerization of lactide and coupling of CO2 and styrene oxide into cyclic styrene carbonate

In the present study, the cobalt (II) complex [Co-HMBED] has been prepared and characterized by spectrochemical techniques, which confirmed its square planar structure. The catalytic activity of the cobalt complex was evaluated towards solvent-free conversion of CO2 and styrene oxide into cyclic styrene carbonate and polymerization of lactide. This perspective describes the synthesis, characterization and catalytic studies of Co-HMBED complex; towards coupling of styrene oxide and CO2 to produce cyclic styrene carbonates and polymerization of lactide.

4-Nonylphenol effects on rat testis and sertoli cells determined by spectrochemical techniques coupled with chemometric analysis

Herein, vibrational spectroscopy has been applied for qualitative identification of biomolecular alterations that occur in cells and tissues following chemical treatment. Towards this end, we combined attenuated total reflection Fourier-transform infrared (ATR-FTIR) and Raman spectroscopy to assess testicular toxicology after 4-nonylphenol (NP) exposure, an estrogenic endocrine disruptor affecting testicular function in rats and other species. Rats aged 21, 35 or 50 days received NP at intra-peritoneal doses of 0, 25, 50 or 100 mg/kg for 20 consecutive days. Primary Sertoli cells (SCs) were treated with NP at various concentrations (0, 2.5, 5, 10 or 20 μM) for 12 h. Post-exposure, testicular cells, interstitial tissue and SCs were interrogated respectively using spectrochemical techniques coupled with multivariate analysis. Distinct biomolecular segregation between the NP-exposed samples vs. control were observed based on infrared (IR) spectral regions of 3200–2800 cm−1 and 1800-900 cm−1, and the Raman spectral region of 1800–900 cm−1. For in vivo experiments, the main wavenumbers responsible for segregation varied significantly among the three age classes. The main IR and Raman band differences between NP-exposed and control groups were observed for Amide (proteins), lipids and DNA/RNA. An interesting finding was that the peptide aggregation level, Amide Ӏ-to-Amide II ratio, and phosphate-to-carbohydrate ratio were considerably reduced in ex vivo NP-exposed testicular cells or SCs in vitro. This study demonstrates that ATR-FTIR and Raman spectroscopy techniques can be applied towards analysing NP-induced testicular biomolecular alterations.

Nanographene Sheet Immobilized Transition Metal Complexes for C-C Coupling Reactions

Transition metal Schiff base complexes covalently immobilized on the surface of amino functionalized graphene sheet to catalyze C-C coupling reaction is reported. Graphene sheet which synthesized using mechanical exfoliation and then by differential oxidative reduction phenomenon of graphite. The schiff base ligand is prepared using aldehyde and amino groups containing compounds which further treated with metal salts to form metal complexes. The as-synthesized metal complexes was then incorporated into amino functionalized nanosheets which are characterized using different spectrochemical techniques. The catalytic investigation of the as-prepared catalyst were done by the cross coupling of aryl halides and aryl boronic acids to form biaryls as product in C-C cross coupling reaction. The yield of the products were high and selective which were analyzed using Gas chromatography technique. The advantage of this catalyst is high stability, recyclability easy recovery of catalyst, environmentally benign and mild reaction condition.

Synthesis, spectral, structural characterization and biological activity of new palladium(II) complexes containing 3‐acetyl‐8‐methoxy‐2H‐chromen‐2‐one derived Schiff bases

Four different mononuclear palladium(II) complexes of 3‐acetyl‐8‐methoxycoumarin Schiff bases were synthesized and characterized by spectrochemical techniques. Further analysis through X‐ray crystallography confirmed the structures of the complexes. Their interactive ability with Calf Thymus DNA and protein (Bovine Serum Albumin and Human Serum Albumin) were investigated by means of absorption and emission methods. The intercalative mode of binding with DNA was supported by EB displacement studies and viscosity measurements. Configurational changes that occurred in the proteins have been analysed with the help of 3D fluorescence studies. The complexes were shown to have good antimicrobial activity against the tested bacterial and fungal pathogens. In addition, antiproliferative activity of the complexes was evaluated on A549 and MCF‐7 cell lines and the complexes were comparatively more active than the standard drug cisplatin. Among the compounds, complex 3 was the most effective against MCF‐7 (IC50 value of 5.20 ± 0.15 μM) and A549 (5.09 ± 0.13 μM) compared with the other complexes 1 (6.48 ± 0.17 μM; 5.98 ± 0.09 μM), 2 (5.53 ± 0.12 μM; 5.85 ± 0.11 μM), 4 (6.73 ± 0.19 μM; 6.63 ± 0.16 μM) and cisplatin (16.79 ± 0.08 μM; 15.10 ± 0.05 μM) respectively. LDH and NO release assays confirmed the cytotoxic potential of the synthesized complexes.

Spectrochemical Analytical Follow up of Phytoremediation of Oil-Contaminated Soil

ABSTRACTTotal Petroleum Hydrocarbons (TPH) are one of the most common groups of persistent environmental toxic organic contaminants to many organisms as well as to humans. In the present work, oil-polluted soil samples were phyto-remediated and analyzed. The investigated soil samples were collected from a location close to the oil petroleum production site in Ras-Gharib, Red Sea, Egypt. The phytoremediation process through TPH reduction and/or removal was carried out using Helianthus annuus (sunflower plant) based on its efficiency as a phytoremediator for organic pollutants. A preliminary four-week scheme of Helianthus annuus remediation, supported by twice quantized fertilization, provided a result of ∼56% clean soil. Contaminated and phyto-remediated samples were diagnosed and analyzed through particle size distribution, Carbon-Hydrogen-Sulfur-Nitrogen elemental analysis (CHSN), Organic Matter content (OM%), Total Petroleum Hydrocarbons determination (%) and spectroscopically through Laser Induced Breakdown Spectroscopy (LIBS) and Laser Induced Fluorescence (LIF). Promising results have been achieved indicating the feasibility of planting sunflower for effective TPH remediation of the polluted soil and also the possibility of in situ monitoring of the remediation with easy, cost effective and fast spectrochemical analytical techniques, namely LIBS and LIF.

Characterization of REE-Nb ores by a combination of spectrochemical techniques

Various spectroscopic techniques and different sample pretreatment schemes were used for the characterization of the uniquely rich Tomtor REE-Nb ores and for the technological solutions used for hydro-metallurgy processing of these ores. The ranges of the target analyte concentrations available for the techniques used, XRF, MP-AES and ICP-MS, were experimentally found. The determination of REE by XRF was possible for concentrations in solid samples above 10−3%. A unique procedure for solid sample borate fusion which resulted in homogeneous, transparent glass disks which were stable during long-term storage was established. Actual concentrations of REE in solid samples were determined using an improved data processing algorithm of XRF spectra evaluation. Metrological parameters for XRF analysis of ore samples were evaluated by the analysis of certified reference materials CRM OSO №250-91 NFS-23 and Nb ore concentrate CRM DH SX18-03.Solid sample digestion was used for the determination of low concentrations of REEs by MP-AES and ICP-MS. The metrological parameters of MP-AES are identical to XRF. ICP-MS was used for determination of 40 elements in technological solutions. In the case of ICP-MS, La, Ce and Nd cause severe spectral interferences for Ga, As and Gd. The quantitative contribution of these interferences was estimated. Correction equations were developed, improving the accuracy of target analyte determination.

Mixed ligand complexes of the novel nanoferrocene based Schiff base ligand (HL): Synthesis, spectroscopic characterization, MOE studies and antimicrobial/anticancer activities

A series of transition metal complexes of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) with (Z)-4-(1-((2-carboxycyclohexa-2,4-dien-1-yl)imino)-ethyl)[bis(η5-cyclopenta-1,3-dien-1-yl)]iron (HL) mixed with 1,10-phenanthroline (Phen.) have been synthesized and successfully characterized using various spectrochemical techniques: elemental analyses, molar conductance, IR, 1H NMR, mass spectroscopy, SEM, thermal analysis (TG/DTG), MOE, biological and anticancer activities. The molecular structures of the HL ligand and its Fe(III) complex were determined by SEM studies. HL ligand acts as a bidentate ligand and coordinates to metal ion center via deprotonated carboxylate oxygen atom and azomethine nitrogen. Also, 1,10-phenanthroline acts as a neutral bidentate ligand coordinates to the metal ion center via two nitrogen atoms. Additionally, mixed ligand complexes were screened against pathogenic antibacterial and antifungal strains: two Gram (+) bacteria; Streptococcus pneumoniae and Bacillis subtilis, two Gram (−); Pseudomonas aeruginosa and Escherichia coli and four fungi; Aspergillus fumigatu, Syncephalastrum racemosum, Geotricum candidum and Candida albicans. The breast cancer cell line MCF7 anticancer activity was studied and a moderate result was the main observation. Molecular docking studies of the HL ligand and its mixed Fe(III), Ni(II) and Cu(II) metal complexes with 1,10-phenanthroline showed the nature of binding energy, H-bond and hydrophobic interactions with the crystal structure of: Tyrosine kinase auto-inhibitor (PDB: 1T46), Staphylococcus aureus nucleoside (PDB: 3Q8U), Human papillomavirus (HPV) pro-apoptotic tumor suppressor (PDB: 4XR8) and breast cancer mutant oxidoreductase (PDB ID: 3HB5).

Evaluation of calcium alginate beads for Ce, La and Nd preconcentration from groundwater prior to ICP OES analysis

Analytical methods for the determination of rare earth elements (REE) in natural waters by plasma spectrochemical techniques often require sample preparation procedures for analytes preconcentration as well as for removing matrix constituents, that may interfere on the analytical measurements. In the present work, calcium alginate (CA) beads were used for the first time aiming at Ce, La and Nd preconcentration from groundwater samples for further determination by inductively coupled plasma optical emission spectrometry (ICP OES). Test samples were analyzed in batch mode by transferring a 40mL test portion (pH=5±0.2) into a 50mL polyethylene flask containing 125mg CA beads. After 15min contact, the analytes were quantitatively extracted from the loaded CA beads with 2.0mL of 1.0molL−1 HCl solution for further determination by ICP OES, using Ce (II) 456.236, La (II) 379.478 and Nd (II) 430.358nm emission lines. The proposed approach is a reliable alternative for REE single-stage preconcentration from aqueous samples, as it provided accurate results based on the addition and recovery analysis of groundwater. The results obtained by the proposed method were also compared with those from reference method based on inductively coupled plasma mass spectrometry (ICP-MS) and no significant differences were observed after applying the Student’s t-test at 95% confidence level.

English

Synthesis of two Schiff base metal complexes of Mn(II) and Co(II). The complexes were analyzed by different Spectrochemical techniques like Vib. FT-IR spectrum - UV-vis spectrum, EPR spectrum. The catalytic activity of both the complexes was observed in cyclohexane and benzyl alcohol using eco-friendly, non-toxic hydrogen peroxide. Both the complexes show better activity towards the oxidation of substrates (cyclohexane and benzyl alcohol). In both the substrates the complex Co (II) shows better activity than Mn(II).