Ethylenediamine Dihydrochloride Research Articles

Synchronous regulation on solvation structure and interface engineering to enable reversible magnesium metal batteries

Magnesium (Mg) metal anodes are highly regarded as one of ideal substitutes for lithium (Li) metal anodes owing to their exceptional volumetric capacity, remarkable safety property, and abundant crustal reserves. However, the development of Mg batteries is severely impeded by the limited availability of electrolyte types, particularly non-nucleophilic ones. Mg(TFSI)2-based electrolyte is a recently discovered type of electrolyte which is non-nucleophilic, easily prepared, and highly stable. Nevertheless, due to its challenging de-solvation process and unexpected passivation interlayers, it is not performing as well electrochemically and requires effective modification. Here, organic amine dihydrochlorides (NCxN·2HCl) are selected as additives to Mg(TFSI)2-based electrolytes to regulate solvation structure and electrode interlayer synchronously. It helps rearrange the solvation sheath of Mg2+ and forms a Mg2+-permeable solid electrolyte interphase (SEI) on the surface of anode, facilitating the kinetic. Amine cations could also guide uniform Mg2+ deposition through electrostatic shielding effects. After experiments and simulations, ethylenediamine dihydrochloride (NCCN·2HCl) stands out, contributing to a significantly reduced overpotential (< 0.2 V), realizing about 100 % coulombic efficiency and stable long-term full cell cycling for an impressive 2400 cycles.

Integrative liquid chromatography-tandem mass spectrometry metabolomics and high-throughput sequencing technology reveal physicochemical characteristics and bacterial diversity of traditionally pickled mustard tuber from different regions of China

Abstract Objectives This work aimed to investigate and compare the physicochemical properties and bacterial diversity of traditionally pickled mustard tuber from different regions in China. Materials and Methods The pickles were obtained from Ningbo (NB), Nei Monggol (NMG), and Harbin (HEB). The pH was monitored by a pH meter. The titratable acidity and salinity were determined via titrimetric analysis. The nitrite content was measured using N-(1-naphthyl)-ethylenediamine dihydrochloride spectrophotometric method. The organic acids were detected by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The bacterial diversity was conducted through Illumina high-throughput sequencing platform. Results There were significant differences in the physicochemical properties of pickled mustard tuber from various locations, with the NB pickles having the highest pH, salinity, and nitrite content and the lowest titratable acidity. Importantly, pickles with higher titratable acidity levels had relatively lower nitrite and salinity contents. A total of 63 organic acids were detected, with lactic acid and succinic acid being the most prevalent. Moreover, the organic acid compositions of the NMG and HEB samples were more similar than those of the NB pickles. Additionally, bioinformatic analysis revealed that Firmicutes and Proteobacteria appeared as the predominant bacterial phyla in all samples. Among these, Lactobacillus was the major genera. The most abundant bacteria were found in the HEB pickles. Further correlation analysis showed that there was a strong correlation between bacterial community and 11 internal physicochemical parameters. Conclusions This study could contribute to a better understanding of the physicochemical characteristics and bacterial diversity of pickled mustard tuber from different locations.

A novel premixing strategy for highly sensitive detection of nitrite on paper-based analytical devices

BackgroundNitrite has been involved in many food processing techniques and its excessive consumption is closely related to the development of different diseases. Therefore, highly sensitive detection of nitrite is significant to ensure food safety. ResultThis study presents a simple and novel strategy for the highly sensitive detection of nitrite in food using paper-based analytical devices (PADs). In this proposed strategy, the nitrite present in the sample undergoes efficient diazotization when initially mixed with sulfanilamide solution before reacting with N-(1-naphthyl) ethylenediamine dihydrochloride (NED) coated on the detection region of the PAD, leading to the maximum production of colored azo compounds. Specifically, within the concentration range of 0.1–20 mg/L, the LOD and LOQ for the nitrite assay using the premixing strategy are determined as 0.053 mg/L and 0.18 mg/L, respectively which significantly surpass the corresponding values of 0.18 mg/L (LOD) and 0.61 mg/L (LOQ) achieved with the regular Griess reagent analysis. SignificanceThe study highlights the critical importance of the premixing strategy in nitrite detection. Under optimized conditions, the strategy demonstrates an excellent limit of detection (LOD) and limit of quantification (LOQ) for nitrite detection in eight different meat samples. In addition to its high precision, the strategy is applicable in the field of nitrite analysis. This strategy could facilitate rapid and cost-effective nitrite analysis in real food samples, ensuring food safety and quality analysis.

Sensitization to ethylenediamine dihydrochloride in patients with contact dermatitis in northeastern Italy from 1996 to 2021.

Ethylenediamine dihydrochloride is a versatile aliphatic amine found in numerous medications and industrial compounds and is a known sensitiser. The sensitization prevalence is affected by geographical and socio-cultural factors. The objectives are to analyse the temporal trend of sensitization to ethylenediamine dihydrochloride in northeastern Italy and to investigate associations with occupations. Between 1996 and 2021, 30 629 patients with suspected allergic contact dermatitis were patch tested with the Triveneto baseline series. Individual characteristics were collected through a standardised questionnaire. The overall prevalence of ethylenediamine dihydrochloride sensitization was 1.29% with percentages similar in both sexes. We observed a significant decreasing trend over time (p < 0.001), yielding a sensitization prevalence <1% in recent years. Among departments, residence in Pordenone area was protective for sensitization. No significant associations were observed with specific occupations. We found significant associations between ethylenediamine dihydrochloride sensitization and being 26-35 years old (odds ratio [OR], 1.47; 95% confidence interval [CI]: 1.05-2.08), and sensitization for many haptens, such as paraben mix (OR, 5.3; 95% CI: 3.3-8.5), epoxy resin (OR, 5.1; 95% CI: 3.0-8.7), neomycin sulphate and mercaptobenzothiazole. Our study showed a downward time trend of ethylenediamine dihydrochloride sensitization in northeastern Italian population and pointed to an update of the Triveneto baseline series.

SmartAgro-Spectral: Teknik Pengukuran Kandungan Nitrit Pada Sarang Burung Walet Berbasis Spektral Menggunakan Metode Regresi Linier

Indonesia is the largest exporter of edible bird’s nest (EBN) to China, involving many EBN farmers from various regions in Indonesia. Therefore, a portable device is needed to rapidly and accurately measure the required quality of SBW to avoid rejection by Chinese buyers, which could result in significant losses. Consequently, for this purpose, an electronic instrument has been developed. smartAgro-Spectral is a microcontroller-based electronic instrument that measures nitrite content in edible bird’s nest (EBN) using linear regression method in machine learning calculations. This instrument can measure nitrite content based on the intensity of colors produced by EBN products. The coloring process is carried out by mixing EBW powder with Sulphanilamide solution and N-(1-naphthyl) Ethylenediamine Dihydrochloride (NED) solution. The concentration of EBN solution is normalized to values between 0.2 ppm and 0.7 ppm. The measurement process is carried out by emitting 18 waves of the light spectrum. The intensity of the 18 wavelengths of the measured light spectrum was selected based on the strong correlation between the intensity of the light spectrum and the value of nitrite content in the EBN product. The measurement results show that the intensity of the light spectrum that has a strong linear correlation is at wavelengths of 460 nm, 485 nm, 510 nm, 535 nm, and 610 nm. So, smartAgro-Spectral electronic instruments can be realized based on the intensity relationship of each wavelength through multiple linear regression analysis, and are able to linearly measure nitrite content in EBW products with a precision level of 99.85% and an accuracy rate of 99.85%.

Conformational stability, quantum computational (DFT), vibrational, electronic and non-covalent interactions (QTAIM, RDG and IGM) of antibacterial compound N-(1-naphthyl)ethylenediamine dihydrochloride

Naphthalene derivatives are heterocyclic compounds with significant applications in the pharmaceutical and biomedical industries. Several spectroscopy methods, including FT-IR, FT-Raman, and UV–Vis, were used in this study to examine the molecular structure of N-(1-Naphthyl) ethylenediamine dihydrochloride (NEDD). By employing DFT through the WB97XD with the level of 6–311++G(d, p) as the basis set, the optimized geometrical characteristics and full vibrational allocations of frequencies by the potential energy distribution were generated and matched to the experimental data. The delocalization of charge caused by intermolecular connections becomes apparent in the natural bond orbital (NBO) study. Additionally, frontier molecular orbital bandgap energy and electron excitation analyses were acquired to provide a deeper understanding of the structural characteristics of NEDD. Frontier molecular orbital energies revealed an energy band gap of 5.505 eV, demonstrating the existence of charge transfer within the molecule. Electronic transitions seen in the experimentally recorded UV–visible spectra were assigned using the TD-DFT method whereas transition density matrix (TDM) plots showed the ability to transmit charges. Considering wave function-derived parameters like the Laplacian of electron density (LED), local information entropy (LIE), the average localized ionization energy (ALIE) as well as non-covalent interactions, provides essential insights into the reactivity and stability traits of molecular systems. Local reactivity descriptions aided in understanding the interactions of physiologically relevant molecular systems, thereby facilitating the discovery of potential pharmaceutical compounds. Drug-likeness and ADMET assessment were achieved to assess biological properties of NEDD. Antibacterial assay confirmed its effectiveness against bacterial strains, while molecular docking studies. The stability of the best docked protein has been investigated using 70 ns molecular dynamics simulation followed by effective free energy calculation using MMPBSA.

Development of efficient fluorescent sensor for the detection of hazard aromatic nitro compounds via N-(1-naphthyl)ethylenediamine: Experimental and DFT studies

Selective detection of the poisonous aromatic nitro compounds (ANCs) in the industrial wastewater is urgently needed to regulate its percentage and thereby aid in environmental protection. The present study describes the application of N-(1-naphthyl)ethylenediamine dihydrochloride (NEDA.2HCl) as a safe and effective fluorescence sensor for the detection of some hazard ANCs including 2,4-dinitrophenol (DNP), O-nitroaniline (ONA), 4-Chloro-2-Nitroaniline (CNA), P-Nitrobenzaldehyde (PNB), O-Nitrobenzaldehyde (ONB). The optical properties of NEDA.2HCl was investigated using both UV–vis and fluorescence spectroscopy at different pH and solvents. Luminescent properties exhibit that NEDA.2HCl has an emission peak at 429.2 nm when it is excited with a wavelength 326.4 nm. The Stern-Volmer equation appears that there is a good relation between the concentration of ANCs under investigation and the fluorescence intensity of NEDA.2HCl with high quenching rates ranging from 8.39 × 103 to 2.74 × 105 mol−1.L. Moreover, the coordination number of the binding sites (n) and the obtained binding constant (Ka) between NEDA.2HCl and ANCs were determined using the modified Stern-Volmer equation to study the behavior of both Ka and n with the variation of the quenching temperature. DFT calculations offered a thorough justification for the discovered quenching activity of the investigated quenchers and the quenching mechanism is proposed to occur through the electron transfer from HOMO of NEDA.2HCl into LUMO of ANCs. This technique offers a quick means to detect and thus reduce the number of hazardous ANCs in the environment, which will be of great benefit to both people and animals.

MALDI Mass Spectrometry Imaging sample preparation with wet-interface matrix deposition for lipid analysis.

Sample preparation is one of the most crucial steps for MALDI mass spectrometry imaging (MALDI-MSI). The scientists beginning their adventure with this technique may be overwhelmed by the variety of matrices, solvents, concentrations, the ways of their applications, and the lack of widely available knowledge about the influence of these parameters on the results. Here we would like to present our experiences with detailed aspects of matrices deposition, hopefully helpful for the scientific community. In our article, we have tested several MALDI matrices applied by the SunCollect® system: wet-interface matrix deposition in the context of lipids analysis. Among them: 2,5-dihydroxybenzoic acid (DHB), norharmane, N-(1-naphthyl) ethylenediamine dihydrochloride (NEDC), 9-aminoacridine (9AA). We have optimized the number of matrix layers and nozzle settings in terms of spectra intensity and the overall quality of obtained ion maps. Our research presents the influence of the number of matrix layers and nozzle settings on the results and allows for choosing the optimal parameters for the analyses. In positive ionization mode, DHB matrix could be chosen as the first selection. In the negative ionization mode, DAN matrix produces higher peak intensity in a lower mass range and seems to provide more information than 9AA. We recommended NEDC for particular tasks such as glucose analysis. Comparably to remaining matrices, norharmane significantly changes received ion maps. Dealing with such a great amount of data allows us to notice an interesting conclusion the obtained ion picture for a particular ion could differ dramatically with changing the matrix, the solvent composition, or even the number of matrix layers. This must be considered when interpreting the result and forces us to compare the results obtained with different matrices with extreme caution.

Modification and validation of an analytical method for the simple determination of nitrate in seawater by reduction to nitrite with zinc powder

As copper-coated cadmium granules, which are recommended for use in the standard method for analyzing nitrate, are environmentally unfriendly and forbidden in some countries, an alternative method is required. To enhance the method for determining low nitrate concentration in seawater, the optimal conditions for reducing nitrate to nitrite using zinc powder were assessed in this study. The modified zinc method was optimal at an 0.8:1 (v/v) ratio of buffer solution (pH 8.5) (4 ml) to water sample (5 ml) with 50 mg of zinc powder and a standing time of 30 min. The nitrite was reacted with sulfanilamide and N-(1-Naphthyl)-ethylenediamine dihydrochloride after nitrate reduction, and spectrophotometrically quantified at 543 nm. This modified method was found to have a linear dynamic range of 0.1–7.0 μM, a low detection limit (0.1 μM), good intra-day and inter-day reproducibility (<5% relative standard deviation), high-efficiency reduction (>95%), and excellent accuracy in analysis of certified reference material (95% relative accuracy). The results obtained using the modified method agreed well with those obtained using the conventional cadmium column method. Overall, this alternative green chemistry method is a simplified procedure for determining nitrate in seawater with a high efficiency.

Enhancing metabolite coverage in MALDI-MSI using laser post-ionisation (MALDI-2).

Matrix-assisted laser desorption/ionisation mass spectrometry imaging (MALDI-MSI) of metabolites can reveal how metabolism is altered throughout heterogeneous tissues. Here negative ion mode MALDI-MSI has been coupled with laser post-ionisation (MALDI-2) and applied to the MSI of low molecular weight (LMW) metabolites (<m/z 600) to investigate the benefits MALDI-2 offers for spatial metabolomics in terms of metabolite coverage and sensitivity. When applied to mouse kidney tissue MALDI-2 provided almost double the number of on-tissue specific mass features compared to conventional MALDI. MALDI-2 also resulted in not only the increased detection sensitivity for multiple metabolite species but also permitted the imaging of LMW metabolites (e.g. uridine) that were not detected using conventional MALDI-MSI. When compared against ∼140 publically available kidney datasets submitted through the METASPACE analysis platform using the same N-(1-naphthyl) ethylenediamine dihydrochloride (NEDC) matrix, MALDI-2 provided 34 unique metabolite m/z features that were not consistently annotated previously. To further evaluate the usefulness of this MALDI-2 approach to metabolite imaging, MALDI-2 was applied to the imaging of mouse liver tissue containing a metastasised breast cancer at a pixel size of 20 μm. Using a co-localisation analysis, MALDI-2 detected six tumour-specific metabolites that were not detected using conventional MALDI, as well as providing an up to 20-fold increase in signal intensities for many others (e.g., glutamate). This work provides one of the first reports of MALDI-2 applied to metabolite imaging and demonstrates the dramatic improvements in sensitivity and metabolite coverage it provides.

A Retrospective Analysis to Investigate Contact Sensitization in Greek Population Using Classic and Machine Learning Techniques.

Allergic contact dermatitis (ACD) is an inflammatory reaction affecting all age groups and both sexes. ACD is characterized by a delayed-type hypersensitivity reaction IV caused by skin contact with haptens. Chronic exposure typically leads to a decrease in erythema accompanied by lichenification (thickening and hardening of the skin) and persistent itching. The current study aims to investigate the patterns of contact sensitization in the Greek population using patch test data analysis. Patch test data from 240 patients (120Males/120Females) with allergic contact dermatitis were collected at the Laboratory for Patch Testing, National Reference Center for Occupational Dermatoses "Andreas Syggros" Hospital in Athens Greece. The contact allergic reactions were caused by ethylenediamine dihydrochloride 1%, thimerosal 0.5%, and methyldibromo-glutaronitrile 0.1% from the European baseline series of allergens; information was also collected for ICDRG evaluation, an extended MOAHLFA index and patient-reported outcomes (daily routine questionnaire). The chi-square test for independence and Spearman's rank were used to evaluate the association and correlation, respectively, between patient characteristics and ACD-related factors. Multiple correspondence analysis (MCA), which is a data analysis approach, was used to find and depict underlying structures in the data collection for nominal categorical data. Statistically significant associations were found between the following pairs of characteristics: eczema triggers and gender and eczema triggers and hand dermatitis. The results from MCA showed that there is correlation between allergic contact dermatitis onset, allergens, and demographic variables.

Non-ionic surfactants in drug delivery vehicles: Physicochemical insights with systems of drugs, Igepal CA-630, bovine serum albumin and hen egg-white lysozyme

Most of the synthetically developed drugs are hydrophobic in nature and hence possess low bioavailability. An efficient delivery of such drugs at the specific target site requires usage of suitable drug delivery vehicles. The quantitative aspects of drug partitioning into delivery vehicles, their release and binding of target protein are crucial for developing guidelines aimed at rational drug design. We have examined the partitioning of anti-thyroid, anti-inflammatory and anti-cancer drugs methimazole, naproxen, imatinib, and (s,s)-n,n′-bis(1-hydroxy-2-butyl)-ethylenediamine dihydrochloride in non-ionic self-assemblies of Igepal CA-630. The use of non-ionic surfactants in drug delivery is important because of their mild and harmless nature. The partitioning of drugs into surfactant micelles have been carried out using calorimetric and spectroscopic techniques. The quantitative details of partitioning mechanism have been investigated using parameters of their interaction such as change in Gibbs free-energy, standard molar enthalpy and entropy. These thermodynamic signatures have allowed us to develop relationships between structure-property and energetics which are very important in rational drug design. The results obtained were compared with different class of drugs having divergent nature to understand the key molecular features in the process of drug partitioning.

Development of new spot test for the identification of ketamine and its application for forensic samples – Blood, injection, and viscera

Ketamine is used as an anesthetic drug and is most prevalent among young adults because it has gained popularity as a date rape drug. There is a lesser number of forensic kits that involve reagents to determine the Ketamine. Therefore, new spot tests are developed to identify the presence of Ketamine majorly in the forensic samples–blood, viscera, and injection. The present study comprises of modified spot test by mixing the standard drug with various reagents such as 1-napthylamin (C10H9N), beta-naphthol (C10H8O), Hydrochloric acid (HCl), N-(1-Naphthyl) ethylenediamine dihydrochloride (C12H16Cl2N2), and Sodium nitrite (NaNO2) for the detection of ketamine. Five spot tests were developed. The GC-MS analysis was further been performed to confirm the presence of ketamine. Therefore, it could be incorporated into the field of forensic toxicology. The new presumptive color tests or spot tests for the illicit drug; ketamine was developed. These tests show good specificity. The compounds which were tested in the present study show the variation of colors as a result when treated with different types of reagents.

Determination of the optimum concentration of the coupling agent in chloramphenicol analysis

The aim of this research is to determine the optimum concentration of the coupling agent used in chloramphenicol analysis, then calculate the limit of detection of that photometric reaction. Chloramphenicol is a colorless compound that is often abused in animals whose products are consumed by humans. Chloramphenicol has side effects on the human body. So, chloramphenicol must be analyzed. To facilitate the analysis process, chloramphenicol must be converted into colored compounds called azo compounds. To make azo compounds must go through the process of reduction, diazotization, and coupling. A coupling agent is an important compound that played a role in an azo compound formation and was analyzed using UV-Vis spectrophotometer. This research, used N-(-1-Naphthyl) ethylenediamine dihydrochloride (NEDA) with variations concentrations of 0.1%, 0.3%, 0.5% at 565 nm. The optimum coupling concentration that gives maximum absorbance was 0.1%. The detection limit (LOD) obtained by using the optimum coupling is 0.0498 μg/mL, the limit of quantitation (LOQ) is 0.1660 μg/mL, the sensitivity value is 0.1425, and a correlation coefficient (R2) of 0.999 with a concentration range of chloramphenicol is 0,14 - 1,4 ppm.

Analysis of Chloramphenicol in Shrimp Using Standard Addition Method Based on Diazotization

This research aimed to determine the concentration of chloramphenicol in shrimp using the standard addition method based on the diazotization reaction using Zn powder as a reducing agent of chloramphenicol, followed by the use of N-(1-naphthyl) ethylenediamine dihydrochloride as a coupling agent and measured at 565 nm. Based on the test, the shrimp sample was found to contain 1964.91 mg/kg of chloramphenicol and it exceeded the requirements set by the European Commission which was 0,15 mg/kg. The limit of detection (LOD) value is 0.19 mg/mL and the limit of quantitation (LOQ) value is 0.64 mg/mL. The correlation coefficient (R2) was 0.9991 for the concentration range of 0-50 ppm. The analysis of the results showed that the %recovery in shrimp analysis using this method was 87.41%-107.73% with an average of 109.38%.

Verifikasi Metode Pengujian Kadar Nitrit dalam Air Limbah Secara Spektrofotometri UV-Visibel

Wastewater is the residue from a business and or activity in the form of liquid. One of the chemical compounds that cause pollution is nitrite. The nitrite level in wastewater is a key parameter in determining water quality because of its toxicity. The standard method for nitrite analysis refers to SNI 06-6989.9-2004 using sulfanilic acid and N-(1-naphthyl)-ethylenediamine dihydrochloride (NED) reagents. Linearity, instrument detection limit (LDI) and quantification detection limit (LOQ), precision, accuracy, and calculation of measurement uncertainty estimation are some of the verification parameters that were tested. The regression curve's results showed that the correlation value (r) = 0.9998, the instrument detection limit value of 0.0014 mg/L, the quantitation limit value of 0.0035 mg/L, the precision value (%SBR) of 1.30 percent, the accuracy value is in the range (90-100)% and the relative uncertainty of 5.88 %. The verification results suggested that the UV-Visible spectrophotometer-based nitrite test technique in wastewater had passed the acceptance requirements and may be utilized for routine laboratory analysis.

Electrochemical Self-Assembled Gold Nanoparticle SERS Substrate Coupled with Diazotization for Sensitive Detection of Nitrite.

The accurate determination of nitrite in food samples is of great significance for ensuring people’s health and safety. Herein, a rapid and low-cost detection method was developed for highly sensitive and selective detection of nitrite based on a surface-enhanced Raman scattering (SERS) sensor combined with electrochemical technology and diazo reaction. In this work, a gold nanoparticle (AuNP)/indium tin oxide (ITO) chip as a superior SERS substrate was obtained by electrochemical self-assembled AuNPs on ITO with the advantages of good uniformity, high reproducibility, and long-time stability. The azo compounds generated from the diazotization-coupling reaction between nitrite, 4-aminothiophenol (4-ATP), and N-(1-naphthyl) ethylenediamine dihydrochloride (NED) in acid condition were further assembled on the surface of AuNP/ITO. The detection of nitrite was realized using a portable Raman spectrometer based on the significant SERS enhancement of azo compounds assembled on the AuNP/ITO chip. Many experimental conditions were optimized such as the time of electrochemical self-assembly and the concentration of HAuCl4. Under the optimal conditions, the designed SERS sensor could detect nitride in a large linear range from 1.0 × 10−6 to 1.0 × 10−3 mol L−1 with a low limit of detection of 0.33 μmol L−1. Additionally, nitrite in real samples was further analyzed with a recovery of 95.1−109.7%. Therefore, the proposed SERS method has shown potential application in the detection of nitrite in complex food samples.

Achieving smooth PZT surface via chemical mechanical polishing with ethylenediamine dihydrochloride

Lead zirconate titanate (PZT) has been widely used in microelectromechanical systems and ferroelectric memory, and a high-quality PZT surface is important to the device performance. In this study, chemical mechanical polishing (CMP) was introduced to process PZT-4 (Pb(Zr0.44Ti0.56)O3). A complexing agent ethylenediamine dihydrochloride (EDA·2HCl) was used as a crucial chemical additive in slurries to improve the CMP performance of PZT-4 because it may chelate metal ions of PZT-4, such as Ti4+. The results show that the material removal rate (MRR) of PZT-4 decreases and the surface roughness Sa increases as pH increases. At pH 4.0, with the EDA·2HCl concentration increasing, the MRR first increases, reaches the summit of 498 nm/min at 0.75 mM, and then decreases and levels off. The Sa has a similar trend. With 50 mM EDA·2HCl, the Sa reaches the minimum value of 3.5 nm, and no processing damage occurs in the substrate. For the removal mechanism, EDA can be adsorbed on PZT-4 probably via forming complex with Ti4+. With a low content of EDA·2HCl, the adsorbates of EDA distribute discretely and can be removed easily, and thus the MRR is high. As the content of EDA·2HCl increases, a relatively continuous and uniform film is formed to suppress dissolution and abrasion, and thus the MRR decreases. A two-step CMP process was developed, and a smooth PZT surface can be rapidly achieved. This study provides mechanistic insight of the role of EDA in the CMP of PZT-4, and may open new avenues of developing CMP slurries for achieving smooth surfaces of PZT materials via screening prospective complexing agents.

Facile Detection of Naphthalene with a 5,10,15,20-tetrakis(4-methoxyphenyl)-21H,23H-Porphine Nickel (II)/N-(1-Naphthyl) Ethylenediamine Dihydrochloride Renewable Graphene Oxide Paste Electrode

We report the fabrication of a new paste electrode based on 5,10,15,20-tetrakis(4- methoxyphenyl)−21H,23H-porphine nickel (II) (NiTPP) and N-(1-Naphthyl)ethylenediamine dihydrochloride (N-NEDDH) for the electrochemical detection of naphthalene. The electrochemical behaviour of the modified N-NEDDH/NiTPP/GO/CPE was studied by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). Under the optimal conditions, the modified sensor presented a wide linear range from 1 × 10−8 to 1 × 10−5 mol l−1 in the detection of naphthalene, with a 3 × 10−9 mol l−1 detection limit. Other polycyclic aromatic hydrocarbons (PAHs), like phenanthrene, anthracene, fluorene and pyrene showed little interference on the detection. It also demonstrated a good applicability on naphthalene determination from four types of water samples, with good recovery rates.

An Experimental Design Approach for Validation and Optimisation of Spectrophotometric Determination of Cefixime in Pharmaceutical Dosage Form

Two simple, sensitive and precise spectrophotometric methods for the assay of cefixime in either pure form or in its pharmaceutical dosage form are described. The method I is based on the reaction of salicylaldehyde with cefixime resulting in a yellow coloured product, absorbs at λmax 425 nm. The second method describes the reaction between the diazotized drug and N-(1-naphthyl)ethylenediamine dihydrochloride to yield a purple coloured product with λmax at 567 nm. The reaction conditions were optimized to get maximum colour intensity. The absorbance was found to extend linearly with increasing the concentration of cefixime the systems obeyed the Beer’s law within the range of 2-10 μg/ml and 5-25 μg/ml for salicylaldehyde and N-(1-naphthyl)ethylenediamine dihydrochloride methods. Common excipients used as additives in pharmaceutical dosage don’t interfere within the proposed analytical methods. The products are stable for over 6 h and 10 h respectively. The proposed methods are simple, sensitive, accurate and suitable for quality control uses.