Chromogenic signaling of water traces by 1,8-naphthalohydrazoneanion complex …

b s t r a c t A naphthalo-1, 8-bis[(2,4-dinitrophenyl)hydrazone] sensor (K) was synthesized and characterized using UVevis, 1H NMR and fluorescence spectroscopy. The sensor showed strong colorimetric and spectral response upon the molar addition of acetate or fluoride ion (AcO
or F
) in acetonitrile. The complexed state (KF or KAcO) of the system showed significant reversibility properties, b…

Rapid high-performance sample digestion of base metal ores usinghigh-intensit…

a b s t r a c t: Infrared sample digestion technology has been rapidly developed in recent years and its application and digestion performance on a variety of ores of base metals was assessed in this study, using a 6-channel infrared digester. Digestion times of 10 min or less were achieved for all base metal ores investigated, including oxides, sulfides, and silicates of Co, Cr, Cu, Fe, Mn, M…

Basic characteristics of quartz crystal sensor with interdigitated electrodes

a b s t r a c t: This paper describes basic characteristics of the quartz crystal sensor with interdigitated electrodes (IDE quartz crystal sensor) which is for imultaneous monitoring of mass, viscosity, conductivity and dielectric changes of liquids or thin films. As the IDE quartz crystal sensor has three terminals for a pair of IDEs on the one side and a counter electrode on the other side…

Evaluation of glycidyl methacrylate-based monolith functionalized with weak a…

a b s t r a c t: In this study, the organic polymer monolith was developed as a weak anion exchanger column in high performance liquid chromatography for DNA separation. Methacrylate-based monolithic column was prepared in microbore silicosteel column (100
0.5 mm i.d.) by in-situ polymerization reaction using glycidyl methacrylate as monomer; ethylene dimethacrylate as crosslinker; 1-propan…

Facilitating the indirect detection of genomic DNA in an electrochemical DNA …

a b s t r a c t A common problem in applying biosensors for the detection of genomic DNA is detecting short sequences in large amounts of long double stranded DNA. A gold electrode modified with a conductive nanocomposite, poly(3,4-ethylene-dioxythiophene), and gold nanoparticles was functionalized with 2,6- Pyridinedicarboxylic acid. Immobilization of a 20-mer DNA probe as the bioreceptor wa…

Rapid detection of fluoride in potable water using a novel fluorogenic compou…

a b s t r a c t: In the present work, we have synthesized a new water soluble colorless chemical compound 7-O-tertbutyldiphenylsilyl- 4-methylcoumarin (TBDPSC) that releases fluorescent molecules imparting blue fluorescence to the solution, upon interaction with fluoride ions in water. The blue fluorescence can be visualized using simple hand held ultraviolet (UV) lamps. TBDPSC has excellent s…

Quantitative measurement of metal chelation by fourier transform infrared spe…

a b s t r a c t: Nutritionally important minerals are more readily absorbed by living systems when complexed with organic acids, resulting in higher consumer demand and premium prices for these products. These chelated metals are produced by reaction of metal oxides and acids in aqueous solution. However, unreacted dry blends are sometimes misrepresented as metal chelates, when in reality the…

Electrochemical behavior of kaempferol and its determination in presence of q…

a b s t r a c t: The electrochemical behavior of kaempferol was investigated by cyclic voltammetry (CV) and square wave voltammetry (SWV) at plane and multiwalled carbon nanotubes modified carbon paste electrode (MWCNTs/CPE). Kaempferol produces an anodic peak at MWCNTs modified CPE with a quasi-reversible nature in phosphate buffer of pH 7.73. The oxidized species of kaempferol was found to …

Cloud point extraction for analysis of antiretrovirals in human plasma by UFL…

a b s t r a c t: An analytical methodology based on cloud point extraction (CPE) coupled to Ultra-Fast Liquid Chromatography and electrospray tandem mass espectrometry (UFLC-MS/MS) was developed for analysis of Abacavir (ABC), Efavirenz (EFV), Lamivudine (3 TC) and Nelfinavir (NFV) in human plasma. It is the first time that CPE was used for extraction of antiretrovirals (ARV) from plasma. The …

Feasibility study of calibration strategy for direct quantitative measurement…

a b s t r a c t: The calibration and quantitative measurement is the ‘‘Achilles heel’’ of the LIBS technique. This paper deals with a method developed for the direct measurement of K and Mg in plant samples. Instrumental parameters were optimized and the best condition found was a 50 lm spot size, 10 Hz laser repetition rate, 75 accumulated laser pulses with 25 mJ/pulse and 0.25 ls of …

Optical sensing of 3-phenoxybenzoic acid as a pyrethroid pesticides exposure …

a b s t r a c t The present communication deals with the synthesis of luminescent Mn-doped ZnS quantum dots (QDs) anchored to surface imprinted polymer for the optical sensing of 3-phenoxy benzoic acid (3-PBA) in urine samples. The combination of sensing and surface functionalization not only improves the selectivity of the method, but also increases the optosensing ability of the material for…

Analytical protocols for the determination of sulphur compounds characteristi…

a b s t r a c t Chlorobium limicola belongs to the green sulphur bacteria that has a potential for technological applications such as biogas clean up oxidising hydrogen sulphide to elemental sulphur through photosynthetic process. In the present work, analytical methods are described for the determination of different sulphur species in C. limicola cultures – sulphide by GC-FPD, sulphate by …

Direct electron transfer biosensor for hydrogen peroxide carrying nanocomplex…

a b s t r a c t: A reagentless electrochemical biosensor for hydrogen peroxide was fabricated. The sensor carries a monolayer of nanocomplex composed of horseradish peroxidase and Au-nanoparticle, and responds to hydrogen peroxide through the highly efficient direct electron transfer at a mild electrode potential without any soluble mediator. Formation of the nanocomplex was studied with visi…

Cross-platform detection of epigenetic modifications from extracted chromatin…

a b s t r a c t: Chromatin contains valuable epigenetic information comprising of bothDNAand post translational histone modifications. Traditionally, detection of epigenetic modifications on DNA and histone proteins requires different and elaborate preparation steps. In this study we report on a facile and unique approach for the simultaneous detection and quantification of epigenetic modifica…

Development and applications of spectrophotometric methods for quantitative d…

a b s t r a c t: This paper describes two simple and novel analytical methods by using spectrophotometric technique for the determination of caroverine a spasmolytic drug in pharmaceutical formulations. The first (A) is a direct method in which analysis of the pure drug was carried out at its kmax 304 nm in ethanol solvent. The method was linear from 0.5 to 18 lg/ml with correlation coefficien…

Development and validation of a high performance liquid chromatography method…

a b s t r a c t The therapeutic benefit of phosphorothioate oligod eoxynucleotides (PS-ODN) containing immune stimulatory sequences has been demonstrated in animal models of cancer and infection. Several tools are available for the determination of these oligonucleotides in biological samples and pharmaceutical preparations, including UV spectroscopy, dye binding, isotopic tracing, capillary g…

Stripping voltammetric detection of nephrotoxic drug cefitizoxime in wastewater

a b s t r a c t: The objective of the present work is to develop the stripping voltammetric method for determination of nephrotoxic drug cefitizoxime in pharmaceutical formulation and its application to wastewater analysis. Solubilized system of different surfactants viz. cationic, anionic and non-ionic influences the electrochemical response of cefitizoxime. Solubilized system of CTAB contain…

Gas sensing properties of indium–gallium–zinc–oxide gas sensors in diff…

a b s t r a c t: We have successfully observed the change in indium–gallium–zinc–oxide (IGZO) gas sensor sensitivity by controlling the light emitting diode (LED) power under the same gas concentrations. The light intensity dependence of sensor properties is discussed. Different LED intensities obviously affected the gas sensor sensitivity, which decays with increasing LED intensity. Hig…

Electrochemical generation of arsenic volatile species using a gold/mercury a…

a b s t r a c t The electrochemical generation of arsenic volatile species (arsine) using an Au/Hg amalgam cathode in a 0.5 M H2SO4 solution, is described. Results were compared with those obtained with other cathodes commonly used for generation of arsine. The effects of the electrolytic conditions and interferent ions have been studied. Results show that the Au/Hg cathode has better toleranc…

Detection of flutamide in pharmaceutical dosage using higher electrospray ion…

a b s t r a c t: Flutamide (2-methyl-N-[4-nitro-3-(trifluoromethyl)phenyl]-propanamide) is a non-steroidal drug that has a specific anti-androgenic activity so that it is used in the treatment of prostate cancer. A simple method for extraction and detection of flutamide from pharmaceutical forms are reported using Soxhlet apparatus combined electrospray ionization tandem mass spectrometry (ES…

Investigation of cobalt porphyrin doped polymer membrane films for the optica…

a b s t r a c t: A cobalt(II) porphyrin was successfully incorporated into polymer membranes for the optical sensing of imidazole and its derivatives. This research has led to a better understanding of the behavior of Co(II) porphyrin in solution and in polymeric membranes. In aprotic dichloromethane (DCM), the Co(II) tetraphenylporphyrin (CoTPP) and Co(II) octaethylporphyrin (CoOEP) show a se…

Quantitative compositional analysis of heparin using exhaustive heparinase di…

a b s t r a c t Heparin is a linear sulfated polysaccharide widely used therapeutically as an anticoagulant. It is also the starting material for manufacturing low-molecular-weight heparins (LMWH). Quality control of heparin and LMWH is critical to ensure the safety and therapeutic activity of the final product. However due to their complex and heterogeneous structure, orthogonal analytical te…

An improved extraction method of rapeseed oil sample preparation for the subs…

a b s t r a c t: The distribution of 19 azole class pesticides in hexane/aqueous–organic mixtures systems and rapeseed oil (or oil solution in hexane)/organic solvents has been studied at 20 ± 1 C. The distribution constants (P) and coefficients (D) between hydrocarbon and polar phase are calculated. It is found that all the studied pesticides are hydrophobic, i.e., in hexane–water syste…

Analysis for commonly prescribed non-sedating antihistamines

a b s t r a c t: A comprehensive review with 185 references for the analysis of commonly prescribed members of an important class of drugs, non-sedating antihistamines (NSAs), is presented. The review covers most of the methods described for the analysis of cetirizine (CTZ), ebastine (EBS), fexofenadine (FXD), ketotifen (KET) and loratadine (LOR) in pure forms, in different pharmaceutical dosa…

Screening of polychlorinated biphenyls in insulating oil using a microfluidic…

a b s t r a c t Polychlorinated biphenyls (PCBs) are persistent organic pollutants in insulating oil of a large number of transformers. A rapid and economical analytical method to detect PCB contamination is still required. To address this issue, we propose here the first microfluidic screening method for PCB contamination in insulating oil. The insulating oil was pretreated using a multilayer…

Unambiguous evaluation of the relative photolysis rates of nitro indolinyl pr…

a b s t r a c t Nitrated indolinyl photoprotecting groups are crucial tools extensively used in the study of neuronal signal transduction. Mononitrated photolabile protecting groups have been used effectively, however, recent advances in the introduction of a second nitro group have shown improvement in the photo efficiency of neurotransmitter (agonist) release, albeit, to varying extents, dep…

A novel coated silver ketamine(I) electrode for potentiometric determination …

a b s t r a c t: A new ketamine coated silver electrode (KCSE) based on ketamine hydrochloride with sodium tetraphenylborate (KT-TPB) as electroactive material has been described. The influence of membrane composition,type of solvent mediators, kind of electroactive materials and interfering ions on the sensor was investigated.The sensor displays Nernstian response of 55.8 ± 0.3 mV/decade ove…

Spectrophotometric determination of iridium after complexation and membrane f…

a b s t r a c t: A simple, ultra sensitive and selective method for the spectrophotometric determination of Ir3+ in various synthetic and environmental samples was reported. The analyte ions were collected on a membrane filter in the form of their red complex with 5-(2-benzothiazolyl-azo)8-hydroxy-quinoline (BTAHQ), and the absorption spectra of the colored membrane filters were acquired. Effe…

Analysis of cave atmospheres by comprehensive two-dimensional gas chromatogra…

a b s t r a c t: In this paper, we describe a simple method for sampling, pre-concentrating, and separating volatile and semi-volatile components from two different cave atmospheres. Sampling is performed by capturing a volume of cave atmosphere in a Tedlar bag or Suma canister for sample storage and transport back to the laboratory. Loading a portion of the sample on a multi-bed sorption tr…

Mixture design analysis of solvent extractor effects on epicatechin, epigallo…

a b s t r a c t: This paper reports an RP-HPLC-UV-DAD study of the effects of four solvents and their mixtures on the extraction and antioxidant activities of three main catechins, epicatechin (EC), epigallocatechin gallate (EGCG) and epigallocatechin (EGC) of Camellia sinensis L. leaves for two harvests. The extraction efficiency solvent was measured by the chromatographic peak areas. The re…

Validated HPTLC method for the simultaneous determination of alfuzosin, teraz…

a b s t r a c t Benign prostatic hyperplasia (BPH) is one of the most common chronic diseases affecting men and itincreases in both incidence and prevalence with age. This work presents a simple, sensitive and fast generic high performance thin layer chromatographic (HPTLC) method for the simultaneous determination of five drugs prescribed for the treatment of BPH. These drugs include the a1-a…

Levels of methoxylated polybrominated diphenyl ethers and polybrominated diph…

a b s t r a c t: PBDEs are widely used brominated flame retardant, which are increasingly reported in the environment. MeO-PBDEs are structural analogs to PBDEs, and reported as natural products and novel pollutants present in the environment. Concentrations of thirteen PBDEs and eight MeO-PBDEs in a large number of commercial sales of hen eggs representing 15 different regions and household p…

Identification of toxic cyclopeptides based on mass spectral library matching

Edisi

(2014), 1

ISBN/ISSN

Doi: 101016/j.ancr.2

Deskripsi Fisik

Analytical Chemistry Research 1 (2014), 8-15

Judul Seri

Analytical Chemistry Research

No. Panggil

-

Parameters affecting the determination of paraquat at silver rotating electro…

Edisi

(2014), 1

ISBN/ISSN

Doi: 101016/j.imic.2

Deskripsi Fisik

Analytical Chemistry Research 1 (2014), 16-21

Judul Seri

Analytical Chemistry Research

No. Panggil

-

Screening of children saliva samples for bisphenol A using stochastic, ampero…

Edisi

(2014), 1

ISBN/ISSN

Doi: 101016/j.ancr.2

Deskripsi Fisik

Analytical Chemistry Research 1 (2014), 1-7

Judul Seri

Analytical Chemistry

No. Panggil

-

Chemical Analysis in the Laboratory: A Basic Guide

Analytical science is recognised as a key technology of critical importance to the needs of the chemical and pharmaceutical industries and of sectors such as agriculture, food, medicine, environment, forensics, engineering etc. It is truly an interdisciplinary science and maybe considered as a virtual sector in its own right. Analytical science provides the measurement information on which…

Quantitative Chemical Analysis

One of our most pressing problems is the need for sources of energy to replace oil. The chart at the right shows that world production of oil per capita has probably already peaked. Oil will play a decreasing role as an energy source and should be more valuable as a raw material than as a fuel. There is also strong pressure to minimize the burning of fuels that produce carbon dioxide, which…