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Analytical and Bioanalytical Chemistry (v.372, #1)
No Title
by Klaus Albert; Manfred Krucker; Tobias Glaser; Alexandre Schefer; Annette Lienau; Daniel Zeeb (pp. 25-26).
No Title by Ciara K. O'Sullivan (pp. 44-48).
Aptamers are artificial nucleic acid ligands that can be generated against amino acids, drugs, proteins and other molecules. They are isolated from combinatorial libraries of synthetic nucleic acid by an iterative process of adsorption, recovery and reamplification. Aptamers, first reported in 1990, are attracting interest in the areas of therapeutics and diagnostics and offer themselves as ideal candidates for use as biocomponents in biosensors (aptasensors), possessing many advantages over state of the art affinity sensors. The properties of aptamers, their applicability to biosensor technology, current research and future prospects are addressed in this short review.
Keywords: Aptamers ELONA Aptasensors SELEX
No Title by Ying Huang; Elizabeth L. Mather; Janice L. Bell; Marc Madou (pp. 49-65).
Completion of the Human Genome Project is driving the rapid development of molecular diagnostics in the laboratory. To accelerate the penetration of genetic tests and other nucleic acid-based tests into clinical markets, simple, compact, automatic sample-preparation systems for molecular diagnostics must be developed. Microelectromechanical systems (MEMS) is a promising approach for the development of automated sample preparation for the clinical laboratory or point-of-care setting. This review discusses MEMS-based components that could be applied to the different stages of the sample-preparation process such as cell separation, nucleic acid purification, and nucleic acid amplification. Examples of functional component integration are given. Issues discussed include partitioning of functions between the instrument and disposable unit, methods of propulsion of fluids and particles, vapor and liquid barriers, and sample size. Although further evaluation and development are needed to provide practical solutions to some of these issues, we conclude that MEMS-based components might contribute to some components in a sample-preparation system consisting of modular instruments and disposable units, but will not provide a generic or a totally integrated solution.
Keywords: Sample preparation MEMS Molecular diagnostics
No Title by D. Collins; M. Lee (pp. 66-73).
Ion mobility spectrometry (IMS) has been used for over 30 years as a sensitive detector of organic compounds. The following is a brief review of IMS and its principles with an emphasis on its usage when coupled to mass spectrometry. Since its inception, IMS has been interfaced with quadrupole, time-of-flight, and Fourier-transform ion cyclotron resonance mass spectrometry. These hybrid instruments have been employed for the analysis of a variety of target analytes, including biomolecules, explosives, chemical warfare degradation products, and illicit drugs.
Keywords: Ion mobility spectrometry Mass spectrometry Gas-phase electrophoresis Plasma chromatography
No Title by Rodriguez I. Pereiro; Carro A. Díaz (pp. 74-90).
Because of their high toxicity and widespread distribution, the reliable selective quantification of alkyl and aryl species containing mercury, tin, or lead has been one of the goals of speciation analysis in recent years. Since becoming commercially available, GC–MIP–AED has been one of the most-used tools in this work. In this paper, the value and limitations of GC–MIP–AED for the speciation of Hg, Sn, and Pb compounds in environmental samples are reviewed and compared with the analytical characteristics of other hyphenated GC-based techniques. Because quantification of Hg, Sn, and Pb species by GC techniques normally requires complex sample preparation involving several steps, the effect of sample-preparation methods on the accuracy and precision of the results is discussed. Finally, we describe the current status of a rapid, low-cost GC–MIP–PED system specifically designed for routine quantification of Hg, Sn, and Pb species in environmental control laboratories.
Keywords: Speciation Mercury Tin Lead Gas chromatography–microwave-induced plasma–atomic emission
No Title by C. Hänel; G. Gauglitz (pp. 91-100).
On the basis of kinetic measurements of biomolecular interactions, a reflectometric interference spectroscopy (RIfS) setup is compared with two commercial instruments. These instruments are based on evanescent wave techniques, surface plasmon resonance (SPR) (represented by BIAcore 2000) and resonant mirror (RM) technique (using IAsys plus). All methods allow a label-free and time-resolved optical detection of biomolecular interaction.These methods are mainly used in biomolecular interaction analysis (BIA). They provide practical techniques for quantifying equilibrium constants and rate constants over several orders of magnitude.The general parameters of the three detectors, namely baseline noise and drift as well as overall sensitivity and limits of detection were compared. The fluid handling and the related implications on the measurements have also been considered.The interaction between thrombine and thrombine inhibitor (TI) was investigated as a test system with the three different methods and the kinetic rate constants were determined and compared. For this TI was immobilized on the surface and binding of thrombine was monitored time-resolved. Determination of the kinetic rate constants could prove that the RIfS set-up is comparable with SPR using BIAcore 2000 and RM technique represented by IAsys plus.
Keywords: Label-free detection Reflectometric interference spectroscopy Biomolecular interaction Thrombine Thrombine inhibitor
No Title by K. Phinney; L. Sander (pp. 101-108).
The applicability of a new Standard Reference Material (SRM) for the evaluation of chiral stationary phase (CSP) performance was demonstrated by utilizing the SRM to characterize the chromatographic behavior of eight commercially available CSPs in liquid and supercritical fluid chromatography. The SRM consists of five ethanolic solutions, each containing one chiral compound. These test mixtures can be used to assess changes in column performance over time and to evaluate lot-to-lot variability in column manufacturing. The SRM was also used to probe the effect of various parameters on column performance.
Keywords: Chiral stationary phase Enantiomers Standard reference material
No Title by A. Jurado-López; M. Luque de Castro (pp. 109-114).
A comparison between a laser-induced breakdown spectrometry-partial least squares (LIBS-PLS) method and methods based on some well-known techniques, such as induced-coupled plasma-atomic emission spectrometry (ICP-AES), flame atomic absorption spectrometry (FAAS), and atomic scanning microscopy (ASM) is presented in order to both validate the content of gold and silver in alloys to be used as solid standards and develop an alternative to the established methods for the hallmark of gold and silver in jewelry pieces. 17 alloys with gold concentrations ranging from 100 to 50% and 8 alloys with silver concentrations between 100 and 80% and variable concentrations of other metals usually present in jewels were used as solid standards in LIBS in order to develop a method as general as possible. The results obtained in the analysis of some alloys (9 for gold and 7 for silver) show that the proposed method is comparable with the official one.
Keywords: LIBS Jewelry Hallmark Gold Silver
No Title by F. Ehrentreich (pp. 115-121).
The wavelet transform has been established with the Fourier transform as a data-processing method in analytical chemistry. The main fields of application in analytical chemistry are related to denoising, compression, variable reduction, and signal suppression. Analytical applications were selected showing prospects and limitations of the wavelet transform. An important aspect consists in showing the advantage of wavelet transform over Fourier transform with respect to dual localization of a signal in both the original and the transformed domain enabling principal new application fields in comparison with Fourier transform.
Keywords: Wavelet transform Wavelet packet transform Raman spectroscopy Spike recognition Infra-red spectroscopy Spectra comparison
No Title by Rudolf Tuckermann; Sigurd Bauerecker; Bernd Neidhart (pp. 122-127).
Evaporation constants of acoustically levitated drops from the homologue series of n-alkanes and 1-alkanols in ambient air have been evaluated by size and temperature measurements. The size of the pure liquid drops, within a diameter range of 0.1 to 2.5 mm, was monitored using a CCD camera, while temperature measurements were carried out by IR thermography. During drop evaporation, water from a humid environment with a relative humidity between 5 and 80% was condensed on the drop surface and in the case of n-pentane, the condensed water froze as a result of the evaporative cooling.
Keywords: Drop evaporation Acoustic levitation Infrared (IR) thermography Drop freezing
No Title by José R. Chirinos; Kaveh Kahen; Su-Ann E. O'Brien; Akbar Montaser (pp. 128-135).
Experimental studies and computer simulations were conducted to identify plasma operating conditions and to explore and contrast the excitation conditions of Ar, Ar-O2, and Ar-He inductively coupled plasmas (ICPs) for the introduction of microliter volumes of sample solutions with a direct injection high efficiency nebulizer (DIHEN). The best MgII 280.270 nm/MgI 285.213 nm ratio (6.6) measured with Ar ICP atomic emission spectrometry for the DIHEN (RF power = 1500 W; nebulizer gas flow rate = 0.12 L min–1) was less than the ratio (8.2) acquired on the same instrument for conventional nebulization (1500 W and 0.6 L min–1). Addition of small amounts of O2 or He (5%) to the outer gas flow improved excitation conditions in the ICP, that is, a more robust condition (a MgII/MgI ratio of up to 8.9) could be obtained by using the DIHEN with Ar-O2 and Ar-He mixed-gas plasmas, thereby minimizing some potential spectroscopic and matrix interferences, in comparison to Ar ICPAES.
Keywords: Direct injection high efficiency nebulizer DIHEN Mixed-gas inductively coupled plasmas Atomic emission spectrometry Matrix interferences Computer simulation
No Title by Attila Gáspár; Éva Széles; Harald Berndt (pp. 136-140).
A recently described thermospray flame furnace atomic absorption spectrometric (TS-FF-AAS) system has been modified in order to extend the applicability of the method for the determination of elemental traces in very small sample volumes (microliter or submicroliter). As an easily available, effective thermospray vaporizer, a fused silica capillary was used and the liquid sample was transported by 1 MPa (10 bar) gas pressure delivered by a standard gas cylinder. A 0.3 µL sample volume can be analyzed with a higher power of detection than using 3 orders of magnitude larger sample volumes with conventional flame atomic absorption spectrometry. The relative standard deviations (N=12) for 0.3 µL volumes and 5 µg/mL Pb samples amount to 3.1% and 3.8% in signal height and signal area, respectively. The detection limit was found to be 69 ng/mL. Initial experiments with other elements (Cd, Hg, Tl, Zn) led to similar results.
Keywords: Thermospray FFAAS Spectrometry, atomic absorption, microthermospray
No Title by Oliver Birkert; Günter Gauglitz (pp. 141-147).
We describe the development of, and analytical conditions used for, parallel affinity assay for thrombin inhibitors adapted to the first label-free optical screening HTS detection set-up fully integrable into a screening platform. To achieve compatibility with pharmaceutical libraries, an HTS-transducer was realized by gluing the bottomless scaffolds of 96- and 384-well plastic microplates on to transducer slides. The transducer are coated with a dextran, to ensure biocompatibility and functionality, and a known thrombin inhibitor was attached covalently to it. By adapting reflectometric interference spectroscopy for simultaneous reading of the whole transducer plate we were able to detect the binding of thrombin in all the wells of the microplates on-line, in parallel, and time resolved. By using an inhibition assay, the screening of 384 substances for thrombin activity can be performed within an assay time of less than 15 min. We also show that the data quality is high enough for parallel quantification of the IC 50 values of the library substances.
Keywords: High throughput screening Label-free detection Thrombin Reflectometric interference spectroscopy Assay development
No Title by R. Lázaro; J. García; A. Pié (pp. 148-154).
Normal values of the parameters of insulin receptors in erythrocytes were provided to make a control group throughout gestation, 24 h postpartum and six weeks after delivery with the aim of comparing them with other parameters with insulin receptor-related pathologies. Thus, one of the purposes of this study was the update of a method to calculate the parameters of insulin receptors in erythrocytes, carrying out several modifications that improved the assay: during binding studies incubation was in continuous rotation shaking, and increasing maximal insulin binding. Other modifications were the increase in the concentration of insulin 125I to 1 ng/mL, and the maximal concentration of unlabeled insulin, 100 ng/mL. Erythrocyte age was considered by the intracellular creatine content providing control values and allowing the normalization of the parameters of insulin receptor during gestation. Data obtained in this study indicated that changes at receptor binding level may be also considered to explain insulin resistance: week 28 showed maximal insulin secretion (16.70±1.44 µU/mL) whereas plasma glucose concentrations remained almost constant (91.14±2.37 mg/100 mL) with respect to the 1st and 2nd trimester of pregnancy (89.73±1.38 and 91.71±2.10 mg/100 mL respectively); insulin reached the point of maximal resistance, which is explained by a decrease of maximum specific insulin binding, %Bo (6.32±0.51) at minimal values due to a decrease of high-affinity receptor number per erythrocyte, N-AA (16±2) at minimal values. Moreover, the negative correlation between progesterone (31.2±0.2 ng/mL) and Ka-AA (r=–0.71) could possibly be related to this maximal resistance.
Keywords: Insulin binding to erythrocytes Insulin receptor in pregnancy Insulin resistance in pregnancy
No Title by Dirk Schaumlöffel; Andreas Prange; Gizelher Marx; Klaus G. Heumann; Peter Brätter (pp. 155-163).
In a new approach to the characterization and quantification of metallothionein isoforms an on-line isotope-dilution method in combination with the coupling of capillary electrophoresis (CE) to an inductively coupled plasma–sector field mass spectrometer (ICP–SFMS) is reported. Metallothionein (MT) isoforms are separated by CE and the elements Cu, Zn, Cd, and S are detected simultaneously by use of ICP–SFMS in the medium resolution mode. On-line isotope dilution is performed by continuous introduction of an isotopically enriched, species-unspecific spike solution after the separation step. MT from rabbit liver and a further purified MT-1 isoform were quantified by determination of sulfur, and the stoichiometric compositions of the metalloprotein complexes are characterized by determination of their sulfur-to-metal ratios.
Keywords: Inductively coupled plasma mass spectrometry Capillary electrophoresis Isotope dilution Metallothionein quantification
No Title by Yoshihiro Saito; Motohiro Imaizumi; Tsutomu Takeichi; Kiyokatsu Jinno (pp. 164-168).
Miniaturized fiber-in-tube solid-phase extraction (fiber-in-tube SPE) has been developed as a solventless sample preconcentration technique for microcolumn liquid-phase separation methods. Short capillaries packed with polymer filaments were employed as the extraction tube and the preconcentration power for phthalates in aqueous solutions was studied. On the basis of the successful on-line coupling of this preconcentration method with liquid chromatography (LC), a more miniaturized extraction cartridge, which is installed in the rotor of the micro-injector, has been developed. With a modified commercially available valve, on-line coupling of this sample preconcentration method to capillary electrochromatography (CEC) was also investigated.
Keywords: Fiber-in-tube solid-phase extraction Miniaturization Sample preparation Microcolumn liquid chromatography Capillary electrochromatography
No Title by Michel Lamotte; Philippe de Violet; Philippe Garrigues; Michel Hardy (pp. 169-173).
Solid-phase extraction has become one of the most commonly used techniques for preconcentration of analytes from environmental samples. In the standard use of solid sorbent phases the extracted pollutants are subsequently eluted with a suitable organic solvent before chromatographic analysis. An alternative to this procedure is analysis of the adsorbed and concentrated pollutants by direct application of a spectroscopic method (fluorimetry or absorptiometry) to the phase. Although this method cannot be expected to give results as precise as those given by chromatographic methods, it might have valuable applications, particularly for "on site" pollution monitoring. This paper reports an evaluation of the capability of the method for the spectrophotometric detection of BTX (benzene, toluene, xylenes) in aqueous media and in contaminated atmospheres, with polydimethylsiloxane (PDMS) as sorbent. The tests performed, with the estimated detection limits, indicate that the method is relatively simple and easy to operate and sensitive enough for application to the monitoring of pollution both in water and in air in an industrial ambient atmosphere.
Keywords: Solid sorbents BTX Pollutants Absorptiometry Fluorimetry
No Title by Lyndon L. Salins; Elizabeth S. Goldsmith; Mark C. Ensor; Sylvia Daunert (pp. 174-180).
A sensing system for nickel based on the nickel binding protein (NBP) from Escherichia coli is shown to be feasible. The versatility of NBP was demonstrated by its use in three different assay formats. When the NBP binds nickel, it undergoes a conformational change that can be used as the basis for an optical sensing system for nickel. The NBP gene was overexpressed in E. coli and the protein purified in a single step using perfusion anion-exchange chromatography. A unique cysteine residue at position 15 in the NBP was labeled with the fluorophore, N-[2-(1-maleimidyl)ethyl]-7-(diethylamino)coumarin-3-carboxamide (MDCC). In a spectrofluorimetric assay, there was a maximum of 65% quenching of the fluorescence signal produced by NBP–MDCC in the presence of nickel. A response curve for nickel using NBP–MDCC revealed a detection limit of 8×10–8 mol L–1. NBP–MDCC was also used to develop assays in microtiter plate and fiber optic bundle formats. Detection limits for nickel using these formats were also in the submicromolar range. Selectivity studies conducted with other divalent metals, including copper, cobalt, iron, cadmium, and manganese, showed that fluorescence quenching for cobalt was similar in magnitude but with a detection limit more than 10-fold higher than for nickel. The quenching responses were lower for the other metals, with detection limits at least 10 to 100 times higher than for nickel. These results suggest that fluorescently labeled NBP is potentially useful in the development of a sensing system for nickel.
Keywords: Fluorescence-based sensor Environmental monitoring Nickel-binding protein
No Title by Masanobu Mori; Wenzhi Hu; Paul R. Haddad; James S. Fritz; Kazuhiko Tanaka; Hirohito Tsue; Shunitz Tanaka (pp. 181-186).
In capillary electrophoresis, it is commonly considered that even a moderately high ionic concentration in the background electrolyte (BGE) leads to high currents, resulting in Joule heating and serious peak distortion. As a new approach to overcome this problem, zwitterionic (Zwittergent-3–14) and/or non-ionic (Tween 20) surfactants have been added to BGEs containing high salt concentrations (e.g. 0.3 M NaCl) and have been shown to result in acceptable separation currents (<200 µA). In turn, these BGEs could be applied to the separation of samples containing high salt concentrations (such as undiluted seawater) without the occurrence of any significant peak broadening due to electrodispersion of the sample. For example, a BGE comprising 10 mM Zwittergent-3–14, 50 mM Tween 20, 0.3 M NaCl and 5 mM phosphate (ph 7) could be used for the determination of UV-absorbing anions in seawater, giving good peak shapes and detection limits of 0.8 µM and 0.6 µM for nitrate and bromide, respectively. The beneficial effects of the non-ionic surfactant on the separation were attributed largely to suppression of the electro-osmotic flow. On the other hand, the zwitterionic surfactant was found to be capable of the incorporation of some anions in accordance with the behaviour of these same surfactants in electrostatic ion chromatography. This incorporation resulted in a decreased conductivity of the BGE and also a change in the separation selectivity of the system.
Keywords: Bromide Nitrate Seawater Capillary electrophoresis Surfactants
No Title by Beate Lilleengen; Grethe Wibetoe (pp. 187-195).
Methods for determination of both the total and extractable content of Cr and Co in soil samples were investigated. For the total content of metal, ultrasonic slurry sampling graphite furnace atomic absorption spectrometry was used and compared with conventional analyses after microwave digestion. The influence of grinding, leaching and homogeneity for slurry sampling was also examined. The concentration of the elements in the analyzed materials were in the range: 50 µg g–1 – 0.4% for Cr and 8–14 µg g–1 for Co. Relative standard deviations (slurry sampling) were in the range 3%–12% for Cr and 0.3%–6% for Co determinations. The detection limit and characteristic mass (peak-area measurements) for Co were 0.14 µg g–1 and 12.6 pg, respectively. For Cr less sensitive wavelengths were used. Excellent agreement with certified reference material was found for total Cr and Co using slurry sampling.EDTA and acetic acid extractions were performed, using protocols given by the Measurement and Testing Programme of the European Commission. The percentages extracted for the different soil samples were 0.3–1.0 for Cr and 2.5–24 for Co. To validate the accuracy of the extractable Cr, CRM 483 Sewage sludge amended soil was analyzed. The values found were 37% and 32% higher than the certified value for EDTA and acetic acid extractable Cr, respectively. The precision for extractable concentration of Cr and Co was about 6% or less. External calibration with aqueous standards, matched to contain the same reagents as the samples, was employed.
Keywords: Chromium Cobalt EDTA/acedic acid extraction Spectrometry, atomic absorption Graphite furnace
No Title by S. Thompson; H. Budzinski; K. LeMenach; M. Letellier; P. Garrigues (pp. 196-204).
A multi-residue analysis procedure using microwave-assisted extraction and pre-purification has been developed for the combined analysis of polycyclic aromatic hydrocarbons (PAH), polychlorobiphenyls (PCB), and organochlorine pesticides (OCP) in marine sediments. This procedure has been validated with certified marine sediment. Several surrogate standards have been employed and the use of octachloronaphthalene (OCN) as a surrogate standard for organochlorine determination in this matrix is discussed. The recoveries of all compounds were high (>70%) and the relative standard deviations are of the same order as the certified values. Different analytical problems are discussed, including DDT degradation in gas chromatography and laboratory PCB background levels. Quantification problems encountered for two pesticides (cis-chlordane and trans-nonachlor) were attributed to PAH interference in the GC–ECD chromatogram.
Keywords: Aromatic compounds Organochlorine compounds Multi-residue analysis
No Title by Sean J. Hart; Gregory J. Hall; Jonathan E. Kenny (pp. 205-215).
A multi-channel detection system utilizing fiber optics has been developed for the laser-induced fluorescence (LIF) analysis of chromatographic eluents. It has been applied to the detection of polycyclic aromatic hydrocarbons (PAH) in a chromatographically overlapped standard mixture and to a complex soil sample extract obtained during fieldwork. The instrument utilizes dual-fiber optic arrays, one to deliver multiple excitation wavelengths (258–342 nm) generated by a Raman shifter, and the other to collect fluorescence generated by the sample at each excitation wavelength; the collected fluorescence is dispersed and detected with a spectrograph/CCD combination. The resulting data were arranged into excitation emission matrices (EEM) for visualization and data analysis. Rapid characterization of PAH mixtures was achieved under isocratic chromatographic conditions (1.5 mL min–1 and 80% acetonitrile in water), with mid µg L–1 detection limits, in less than 4 minutes. The ability of the instrument to identify co-eluting compounds was demonstrated by identifying and quantifying analytes in the rapid analysis of a 17 component laboratory-prepared PAH mixture and a soil extracted sample. Identification and quantification were accomplished using rank annihilation factor analysis (RAFA) using pure component standards and the EEMs of mixtures measured during the rapid high-performance liquid chromatography (HPLC) method as the unknowns. The percentage errors of the retention times (RTs) determined using RAFA compared to the known RTs measured with a standard absorbance detector were between 0 and 11%. For the standard PAH mixture, all 17 components were identified correctly and for the soil extracted sample, all 8 analytes present were correctly identified with only one false positive. Overall, the system achieved excellent qualitative performance with semi-quantitative results in the concentration predictions of both the standard mixture and the real-world sample. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00216-001-1125-6.
Keywords: Hydrocarbons, polycyclic aromatic Fluorescence, laser-induced Fiber optic array Chromatography HPLC
No Title by Christopher J. Smith; Wenlin Huang; Charisse J. Walcott; Wayman Turner; James Grainger; Donald G. Patterson (pp. 216-220).
For measurement of biomarkers from polycyclic aromatic hydrocarbon (PAH) exposure, an analytical method is described quantifying hydroxylated PAH (OH-PAH) in urine samples. This method determined monohydroxy metabolites of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, chrysene, benzo[c]phenanthrene, and benz[a]anthracene. The sample preparation consisted of enzymatic hydrolysis, solid-phase extraction and derivatization with a silylating reagent. Five carbon-13 labeled standards were used for isotope dilution. Analytes were separated by gas chromatography (GC) and quantified with high-resolution mass spectrometry (HRMS). This method produced good recoveries (41–70%), linearity, and specificity. Data were corrected for blank levels from the naphthalene, fluorene, and phenanthrene metabolites. Method detection limits ranged from 2 ng L–1 for 1-hydroxypyrene to 43.5 ng L–1 for 1-hydroxynaphthalene. Using quality control charts from two urine pools, the method can be readily applied to biomonitoring PAH exposure.
Keywords: Polyaromatic hydrocarbons Isotope dilution High resolution mass spectrometry Human urine Solid-phase extraction
No Title by Piero Mirti; Patrizia Davit; Monica Gulmini (pp. 221-229).
Glass fragments dating from the seventh and eighth century AD were excavated in the Crypta Balbi in Rome. They were studied to detect agents involved in colour development and opacification. Reflectance spectra recorded on powdered samples revealed the contribution of Fe(II), Fe(III), Mn(III), Cu(II), and Co(II) ions in determining colour hues. The effect of the Mn/Fe atomic ratio on glass colour is discussed. It is apparent that medieval glassmakers in Italy could obtain a wide range of colours by exploiting the presence of iron and manganese as contaminants of sand and flux and controlling the amount of oxygen let into the furnace. X-ray diffraction and scanning electron microscopy coupled with energy-dispersive X-ray analysis were used to study opaque fragments. The presence of calcium antimonate was detected in white, blue, and blue-green fragments, and elemental copper was detected in a red glass.
Keywords: Ancient glass Colourants Opacifiers Reflectance spectroscopy x-raydiffraction SEM-EDS Archaeometry