Current Analytical Chemistry - Volume 13, Issue 4, 2017

Background: Doxorubicin (Dox) is a medicine for cancer chemotherapy in various cancers, such as leukaemia, lympyoma and breast cancer. However, the Dox metabolite induced cardiotoxicity. Therefore, how to monitor exactly the concentration of Dox and its metabolites in plasma or serum is an important issue. Methods: Doxorubicin was dissolved in ethanol to prepare 10000 μg/mL solutions. Doxorubicin solution (20 μL) was transferred into two tubes and each tube was adjusted the pH value to 5.6 using sodium acetate buffer (160 μL). The samples were allowed to react with 10 μL 4% formaldehyde-H2 and 10 μL 4% formaldehyde-D2 solutions for 5 min, respectively. Eventually, the modified samples were reduced for 1 h in the presence of 0.6 M NaBH3CN (10 μL). Individual samples were injected into the mass spectrometer by syringe to determine m/z values and establish MRM transition. The signal enhancement, illustration of calibration curve, and method validation were according to the MS detection of MRM transitions between modified and unmodified compounds. Results: The signal of modified Dox was enhanced by reductive amination, and the signal enhancement was improved 190.8% which was compared with unmodified Dox. The linearity of doxorubicin was illustrated from the range of 5.0-1000.0 ng/mL, and the limit of detection and the limit of quantitation were 1.37 and 1.46 ng/mL, respectively. The method validation was spiking doxorubicin with low, intermediate, and high concentrations including 20 ng/mL, 100 ng/mL, and 500 ng/mL in human serum, and recoveries were between 80% to 98%. Conclusion: Via reductive amination of formaldehyde, a novel, laborless, inexpensive and convenient method was developed for the absolute quantification of doxorubicin. Furthermore, doxorubicin would be reduced to generate doxorubicinol which is a metabolite of doxorubicin. Therefore, this method could be utilized to quantitate doxorubicin as well as doxorubicinol. The quantification of doxorubicin and its metabolite, doxorubicinol, could share the same internal standard and standard for calibration curve illustration. Besides, the novel modification of reductive amination enhanced MS signal intensities, facilitating the absolute quantification of doxorubicin.

Background: Concerns has been raised for developing flexible, lightweight, sustainable and environmental friendly energy storage and conversion device to meet the energy demand of the modern society. In the recent past, supercapacitors have gathered much attention as a promising electrochemical energy storage system because of its high power density, excellent cycle life and rapid chargedischarge. The key element for developing supercapacitors is the electrode material. These electrode materials can be comprised of conducting polymers like (polypyrrole, polythiophene and polyaniline) with metal oxides like (RuO2, MoO2, and MnO2) and carbon materials like carbon nanotubes (CNTs), graphene and activated carbons. In this study, we report the synthesis of polyaniline (PANI) and CNTs composites doped with varying concentrations of copper and nickel transition metal ions via in-situ chemical polymerization with a purpose to enhance the capacitive behaviour of PANI. The synergistic impact resulting from the incorporated metal ions, CNTs and pseudocapacitive polymer have been analyzed. Methods: Electrode materials with high specific capacitance have been obtained by coating metal doped polyaniline over carbon nanotubes via surfactant based in-situ oxidative polymerization method. Results: Physico-chemical characteristics of the prepared composites were evaluated by means of FTIR, UV-Visible and XRD techniques. The spectroscopic results confirm the incorporation of CNTs and metal ions in the polymer composites. Also, it has been depicted that the structural backbone of polymer chains has changed very little in the doped polymer composites and a good interaction of hetero atom of polymer with CNTs and metal ions has been indicated. Powder XRD technique revealed the ordered alignment of polymer chains in the composites, additionally, the composites display increased intensity of peaks SEM analysis observed a uniform and porous layer of doped polymer coated over CNTs to yield a nanorods like structure. The capability of nanocomposite electrode materials has been found to increase with the doping level of the metal. Highest specific capacitance value of 1337F/g was obtained for the composite sample with maximum doping level. Electrochemical impedance spectroscopy measurements calculated a minimum solution resistance Rs=1.41Ω for the same composite. Conclusion: Successful design and fabrication of metal doped polymer composites have been achieved. The increment of capacitance has been observed with the increasing concentration of metal ions in polymer composites, amongst various composite samples, the composite having highest metal doping reports highest specific capacitance and a minimum solution resistance. The composite retains 76% of initial specific capacitance at a high scan rate of 100 mV/sec. These valuable characteristics offer good compatibility of these composites for energy storage and conversion systems.

Background: Antimony is a metaloide that offers human health risks. Then, the determination of this chemical element in food samples is always opportune. This paper proposes a method for determination of total antimony in fish muscle tissue using hydride generation atomic absorption spectrometry (HG AAS). Methods: The optimization of the quantification step was performed using a two-level full factorial design and a Box Behnken matrix, involving the factors: nitric acid concentration, carrier gas flow (argon) and sodium borohydride concentration. The digestion procedure of the samples was established employing microwave assisted radiation using nitric acid. Results: The method using the optimized conditions allows the determination of total antimony by the external calibration technique with limits of detection and quantification of 0.8 and 2.6 ng g-1 for a sample mass of 0.20 g, and precision expressed as relative standard deviation of 4.32%, for an antimony solution of concentration 5 μg L-1. The accuracy was confirmed by analysis of a certified reference material of oyster tissue furnished by National Institute of Standards and Technology (NIST). Conclusion: The method was applied for determination of total antimony in seven samples of fish muscle tissue (Arraia - Brazilian name, Elasmobranquiomorpha rajiformes) acquired in two regions of the Todos os Santos Bay, Bahia, Brazil. The antimony content found varied from 62 to 370 ng g-1. These results are agreeing with other data reported by literature.

Background: This study describes a simple and rapid analytical method for the simultaneous determination of trace amounts of copper(II), zinc(II), nickel(II), cobalt(II), iron(II), cadmium(II) and mercury(II) in fish samples by the reversed-phase highperformance liquid chromatography (RP-HPLC) with di-2-pyridyl ketone benzoylhydrazone (DPKBH) as pre-column derivatization reagent. Methods: Seven metal chelates were successfully separated with methanol:acetonitrile:tetrabutyl ammonium bromide (1.0 mM):water mixture containing ammonium acetate buffer (pH 6.0) and DPKBH (1.0 mM) (40:24:1:30:5, v/v/v/v/v) as mobile phase on a C18 column at a flow rate 1.0 mL min-1 at 370 nm. Results: Under the optimum conditions, reproducibilities of analyte retention times (relative standard deviation (RSD) ≤ 0.04%) and peak areas (RSD ≤ 1.5%) were found to be good with the lineraties R2 ≥ 0.9995. The validation of the method was performed by the analysis of certified reference materials. Conclusion: The method developed was applied for the determination of Cu(II), Zn(II), Ni(II), Co(II), Fe(II), Cd(II) and Hg(II) in fish samples.

Background: Hawthorn species (Crataegus) belonging to the Rosaceae family is one of the most commonly used phytopharmaceuticals against mild cardiovascular diseases. The use of medicinal herbs is regulated by the World Health Organisation regarding their content of toxic elements. Thus it is important to study the elemental pattern of the plant organs used to ensure safe use on the one hand and sufficient amounts of essential elements on the other hand. Method: In the present study leaves and flowers of two Hawthorn species, namely Crataegus monogyna and Crataegus oxyacantha grown in a remote area were analysed for their contents of essential and harmful elements by atomic spectrometry. The metal concentrations in the soil were determined as basis for the calculation of the Biota Soil Accumulation Factor (BSAF). Results: It was found that all plant parts analysed do not contain toxic elements above the regulated limits. Furthermore, the uptake pattern of the two plants are different for certain elements, a fact which can be used for identification of leaves and flowers and for adulteration detection. Conclusion: White and Red Hawthorn (Crataegus monogyna and Crataegus oxyacantha) can be distinguished not only by shape, structure and colour, but also on their metal concentrations in leaves and flowers. This fact can be used for identification of leaves and flowers and for adulteration detection. Leaves and flowers of these two plants grown in the remote area in Croatia do not pose any risk to humans when used for medicinal purposes.

Introduction: The growing textile industry has posed a prudent threat to already depleting freshwater resources. Therefore, it is essential to treat dyes from effluents prior to their discharge using some low-cost adsorbents in the scenario of developing countries like Pakistan. Objectives: The current manuscript deals with the screening of agriculture and forest waste adsorbents for removal of hazardous malachite green (MG) dye. Further white cedar sawdust (WCS) is first ever explored for preferential MG dye adsorption potential and process optimization. Methods: Process variables of MG dye adsorption onto WCS are optimized in batch reactors. Analytical techniques of FTIR, SEM and BET were used to identify various functional groups, surface morphology and surface area of WCS respectively. Different adsorption isotherm and kinetic models were applied to obtain theoretical data of MG adsorption onto WCS at variable initial dye concentrations of 30 - 100 mg L-1. Spontaneity and enthalpy of the system was investigated through thermodynamic studies. Moreover, WCS is also explored for preferential adsorption of MG dye in binary component system with orange II (OII) dye. After adsorption, the residual dye concentration was determined at 616 nm and 485 nm for MG and OII, respectively, using UV-Visible spectrophotometer. Results: Increasing initial dye concentration, adsorbent dose and pH increased the adsorption of MG onto WCS. The primary and secondary macroporosity and functional groups (O-H, O-CH3, C-O, C-OH, C-H) were involved in the adsorption of MG dye. Adsorption data followed pseudo-second order kinetic and Langmuir (R2=0.999) models. MG biosorption process was spontaneous at higher temperatures. The adsorption of MG and OII dyes shrink by 21% and 60%, respectively, during the binary system as compared to single component system. Conclusion: WCS can be successfully utilized as an alternative low-cost adsorbent for the treatment malachite green dye from aqueous solution. This adsorbent remain effective for MG dye adsorption by 80% if it is used for the treatment of binary component system.

Objective: A comprehensive monosaccharide quantifying method was developed in this article. Monosaccharides (including glucose, arabinose, galacturonic acid, galactose, mannose, rhamnose and xylose) were analyzed by RP-HPLC-DAD method. Meanwhile, mannitol and fructose were calculated based on peak areas obtained by HPIEC-RID and corresponding data obtained by RP-HPLC-DAD. Monosaccharide compositions of CDSC were analyzed, nine kinds of monosacchardes (glucose, arabinose, galctose, galacturonic acid, mannose, rhamnose, xylose, fructose and mannitol) in were quantified. Background: Cistanche deserticola Y. C. Ma, is a perennial holoparasite and mainly distributed in the desert region of northwestern China. It reported that C. deserticola soluble carbohydrate (CDSC) could prompt lymphocyte proliferation, modulate immunity, inhibit type 2 diabetes, anti-inflammation. For these reasons, it is very appealing to researchers to have a convenient method for monosaccharides analysis of the CDSC. However, previous researches have neglected the faultiness in monosaccharide composition analysis. Therefore, in this study we will focus on establishing a quantifying method of monosaccharides possibly found in C. deserticola. Methods: Soluble carbohydrates were hydrolyzed with trifluoroacetic acid, monosaccharides were labeled with 1-phenyl-3-methyl-5-pyrazolone (PMP), separated by HPLC system equipped with C18 column and detected with DAD (RP-HPLC-DAD). RP-HPLC-DAD method was used for quantitative analysis of glucose, arabinose, galacturonic acid, galactose, mannose, rhamnose and xylose. Meanwhile, hydrolyzates were separated by HPIEC system equipped with aminex HPX-87H ion exclusion column and detected by refractive index detector (HPIEC-RID). The quantity of mannitol and fructose can be calculated based on peak areas obtained by HPIEC-RID and corresponding data obtained by RP-HPLC-DAD. Results: Utilizing this method, monosaccharide compositions of CDSC with different molecular weight (CDCSA, CDCS-B, CDCS-C and CDCS-D) were analyzed, nine kinds of monosacchardes (glucose, arabinose, galctose, galacturonic acid, mannose, rhamnose, xylose, fructose and mannitol) in were found. Conclusion: Fructose and mannitol, which are abundant present in C. deserticola, cannot be analysis by normally PMP modify method, therefore, a comprehensive quantitative analysis method was developed in this research. Galacturonic acid was found out in macro-molecular polysaccharides from C.deserticola, which was not reported before. Galactose and galacturonic acid mainly exist in macro-molecular polysaccharide. Fructose and mannitol mainly exist in mini-molecule or exist in free form.

Background: Quantitative structure-mobility relationships are proposed to estimate the electrophoretic mobility of diverse sets of analytes in capillary zone electrophoresis using Abraham solvation parameters of analytes, namely the excess molar refraction, polarizability, hydrogen bond acidity, basicity, and molar volume. Multiple linear regression (MLR) as a linear model, adaptive neuro-fuzzy inference system (ANFIS), and artificial neural network (ANN) methods were used to evaluate the nonlinear behavior of the involved parameters. The applicability of the Abraham solvation parameters to the mobility prediction of analytes was studied employing various datasets consisting of organic acids, benzoate derivatives, pyridines, and ammoniums. Methods: To evaluate the simulation ability of the proposed models, datasets were subdivided into training and test sets in the ratio of 3:1. To evaluate the goodness of fit of the models, squared correlation coefficients (R2) between experimental and calculated mobilities were calculated. Results: R2 values were better than 0.78 for all datasets except for organic acids, in which the ANFIS model showed better ability to predict their mobility than that of MLR and ANN. In addition, the accuracy of the models is calculated using mean percentage deviation (MPD) and the overall MPD values for test sets were better than 15% for all models. Conclusion: The results showed the ability of the developed models to predict the electrophoretic mobility of analytes in capillary zone electrophoresis.

Background: The solution scannometric technique was introduced recently by Abbaspour et al. They used commercially available flatbed-scanners for obtaining the images of color solutions. The obtained images have been transferred to computer for analyzing and determining the intensity of color solutions. The method is based scanning of solution phase, in Plexiglas® cells. Finally the RGB (red, green and blue) color model was used in color monitor. In our previous work CPE-Scanometry was introduced for determination of one component (fast green FCF) in aqueous solutions. Methods: In this work for the first time UACPE-Scanometry as new, fast, facile, cheap and sensitive method was used for simultaneous separation, preconcentration and determination of Auramine O (AO) and Crystal Violet (CV) in aqueous samples. For the cloud point extraction, aliquots of solution containing the analytes, Triton X-114 (0.23% w/v), KCl (0.05 mol L-1) and NaClO4 (0.05 mol L-1) electrolytes were mixed in 15 mL centrifuge tube then pH of solution adjusted to the desired value. The solution was diluted to the mark with double distilled water and allowed to stand for 2.5 min in ultrasonic bath for accelerating phase separation. separation of the aqueous and surfactant-rich phase was accomplished by centrifugation for 10 min at 3500 rpm. Then the dilute phase was carefully removed with a pipette and the surfactant rich phase was diluted with ethanol to 500 μL, and 480 μL of this solution was injected into the one cell on Plexiglas® sheet, and similar way to other cells. After shaking, the color cells were scanned with the scanner and the obtained images of the color solutions were analyzed to evaluate R, G and B contents by the developed software. Results: The influence of operation parameters including such as pH, concentrations of surfactant and electrolyte on the cloud point extraction of both dyes were investigated and optimum conditions were established. Under the optimum experimental conditions calibration graphs were linear in the range of 0.02-2.7 and 0.06-5.0 mg L-1 with detection limits of 0.01 and 0.04 mgL-1 for CV and AO, respectively. Also the precision (%RSD) for seven replicate determinations of the analytes was better than 2.45%. Finally, the proposed method was utilized successfully for the determination of CV and AO in surface water (river), tap water and industrial waste water samples. Conclusion: In this paper, CPE-Scanometry as a new method was used for the simultaneous determination trace amount of two dyes for the first time. Crystal violet and Auramine O were chosen as templates for this purpose. The proposed method employs cloud point extraction and the scanometry method. This method offers novelty, facility, high speed, sensitivity, low cost and safety.