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Wielopierwiastkowa analiza materiałów opakowaniowych techniką ICP-TOFMS

Skrzydlewska E., Balcerzak M.

Wiadomości Chemiczne

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2004

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[Z] 58, 11-12

915--942

EN

In 1994 new legislation (Directive 94/62/EC [12]), limiting the level of the most toxic heavy metals (Cr(VI), Cd, Hg and Pb) in packaging materials to 100 mg kg-1 (as a total amount) was introduced in the European Union. The Directive has become the basis for corresponding legislation acts in the EU member and candidate countries, including Poland [13-16]. These events have focused the attention of the scientists to the necessity of development of methods suitable for the examination of enormous amounts and a variety of packaging materials for trace amounts of elements (ng g-1, ?g g-1) that can occur in such materials. Papers, paperboards and plastics make the basis of packaging materials used. Traces of toxic substances in such materials can origin from contaminants occurring in various substrates (e.g. wood pulp, polymers), from numerous additives (e.g. catalysts, thermal stabilizers, adhesives, lubricants, antioxidants, pigments, printing inks) used in the production process as well as from process water and process equipment. A discussion of packaging materials produced as well as sources of toxic elements is presented in the paper in detail. Analytical methods for the determination of traces of various elements (chromium, cadmium, lead, mercury, arsenic, antimony, molybdenum, barium, copper and zinc) in packaging materials developed by the authors have been described. Digestion procedures used for the transformation of the analytes from materials of various matrices (polymer (polyethylene, polypropylene, polystyrene, poly(ethylene terephthalate)), paper and paperboard) into solution are presented in Table 1. The application of modern analytical technique, inductively coupled plasma-time of flight-mass spectrometry (ICP-TOFMS), to the detection of the elements has been described. The ICP-TOFMS technique offers detection limits (DLs) suitable for the determination of a range of elements that can occur in packaging materials. The technique offers multi-element capability, selectivity, possibility of simultaneous isotope determinations, extremely high data-acquisition speed (quasi-simultaneous measurement of all masses extracted from the plasma ion source), high ion transmission and high sample throughput [34, 35]. Data for the isotopes used for the detection of the analytes as well as the detection and quantification limits achieved by the authors are given in Table 2. Results for the level of the elements determined in four groups of packaging materials examined, I and II: of polymer matrices intended for food- and non-food-packagings, respectively, and III and IV: of paper and paperboard matrices (for food- and non-food-packagings, respectively) have been given in Table 3. Mass spectra of some materials chosen from particular examined groups are presented in Fig. 2.

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Spektrometria mas z indukcyjnie sprzężoną plazmą i analizatorem czasu przelotu jonów (ICP-TOFMS)

Skrzydlewska E., Balcerzak M.

Wiadomości Chemiczne

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2003

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[Z] 57, 9-10

907--933

EN

This paper presents a powerful analytical technique which uses an inductively coupled plasma (ICP) ionization source and mass spectrometric (MS) detector with a time of flight (TOF) analyzer. The technique has been introduced in 1993 and has attracted rapidly the attention of researchers in the field of atomic spectroscopy as a method that offers substantial improvement of figures of merit of widely used ICP-MS technique with quadrupole filters. A mass spectrum in ICP-TOFMS technique is generated for a packet of ions simultaneously extracted from a continuous ion beam generated in plasma and accelerated to the same kinetic energy (Ek = 0.5 mv2). Setting the ions to the same kinetic energy results in different velocities acquired by the ions of different masses. The separation of the ions of different m/z is accomplished due to different times of their passing a fixed path (field-free region) in the instrument. Extremely low time difference (nanosecond regime) between adjacent masses reflects in quasi-simultaneous detection of all isotopes reaching the detector. The technique offers extremely high speed: spectral frequency 20-30 kHz (i.e. 20000-30000 mass spectra can be accumulated per second), an ability to obtain full elemental analysis for a packet of ions extracted from a continuous ion beam and a significantly better, as compared with quadrupole ICP-MS, precision of the measurements. Analytical performance and applicability of the technique in multi-clemental analysis of various materials have been extensively examined since 1998 when the ICP-TOFMS spectrometers have been commercially available (from LECO, USA („LECO Renaissance") and GBC, Australia („Optimass 8000")). The technique has turned to be particularly suited for detection of fast transient signals generated, e.g. by laser ablation, chromatographic systems, capillary clectrophoresis and FIA. The basic principles, analytical capabilities of the ICP-TOFMS technique and characteristics of the instruments used are discussed in this paper. Analytical applications of the technique are presented.

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Determination of traces of toxic elements in laminated plastic food packaging materials by inductively coupled plasma time-of-flight mass spectrometry (ICP-TOFMS)

Skrzydlewska E., Balcerzak M.

Chemia Analityczna

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2003

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Vol. 48, No. 6

909-918

EN

The content of Cr, As, Cd, Sb and Pb has been determined in laminated plastic food-packaging materials of polyethylene (an overprinted low-density polyethylene/Al/polyethylene terephthalate/low-density polyethylene (LDPE/A1/PET/LDPE)) and polypropylene (an overprinted oriented polypropylene/oriented polypropylene (OPP/OPP)) matrices. The samples were digested in the mixture of nitric acid and hydrogen peroxide in the high-pressure microwave mineralizer. Inductively coupled plasma-time of flight-mass spectrometry (ICP-TOFMS) has been used for the detection of the analytes. The obtained detection limits were within the range 0.010 ((123)Sb)-0.117 ((75)As) ng g(-1)'. In LDPE/A1/PET/LDPE matrix one determined chromium (0.33 mg kg(-1), antimony (1.81 mg kg(-1)) and lead (0.53 mg kg(-1)) while only chromium (0.31 mg kg(-1)) and lead (1.06 mg kg(-1)) were detected in OPP/ OPP. The contents of other elements were below the detection limits. Certified reference material: polyethylene BCR-681 served for the accuracy studies.

PL

Oznaczono śladowe ilości chromu, arsenu, kadmu, antymonu i ołowiu w dwóch rodzajach laminatów: z matrycą polietylenową (zadrukowany polietylen o małej gęstości/Al/polite-reftalan etylenu/polietylen o małej gęstości (LDPE/A1/PET/LDPE)) i polipropylenową (zadrukowany orientowany polipropylen/orientowany polipropylen (OPP/OPP)). Próbki laminatów rozkładano w mieszaninie kwasu azotowego i nadtlenku wodoru w wysokociśnieniowym mineralizatorze mikrofalowym. Do detekcji analitów zastosowano spektrometr mas z jonizacją w indukcyjnie sprzężonej plazmie i analizatorem czasu przelotu jonów (ICP-TOFMS). Uzyskano granice detekcji w zakresie 0,010 ((123)Sb)-0,117 ((75)As) ng g(-1). W laminacie LDPE/A1/PET/LDPE oznaczono chrom, antymon i ołów w ilościach odpowiednio: 0,33; 1,81 i 0,53 mg kg(-1). W drugim badanym materiale (OPP/OPP) oznaczono chrom (0,31 mg kg(-1)) i ołów (l ,06 mg kg(-1)). Stężenia pozostałych pierwiastków były poniżej uzyskanych granic detekcji. Analiza certyfikowanego materiału odniesienia: polietylenu BCR-681 posłużyła do oceny dokładności uzyskanych wyników.

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Nowoczesne techniki analityczne wykorzystujące plazmę indukcyjnie sprzężoną jako źródło wzbudzenia i jonizacji

Skrzydlewska E., Balcerzak M., Pasławski P.

Wiadomości Chemiczne

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2002

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[Z] 56, 5-6

493-521

EN

Plasma spectrometric techniques: inductively coupled plasma-atomic emission spectrometry (ICP-AES) and inductively coupled plasma-mass spectrometry (ICP-MS) are rapidly becoming the most important analytical tools for the determination of trace amounts of elements. High speed, excellent detection limits, wide dynamic range and possibility of accurate multi-element analysis make the techniques particularly suited to the determination of ppb and sub-ppb levels of the analytes in complex matrices. Mass spectrometric methods offer unique capability of rapid isotopic ratios measurements. Plasma techniques have found wide applications in analysis of geological, environmental and clinical samples. They have proved to be very useful in speciation studies due to extremely low sensitivities offered and the ease of on-line combination with separation techniques, in particular with chromatography. A brief review of ICP-AES and ICP-MS techniques is presented in the paper. The possibility and limitations of the techniques as analytical tools are discussed. The most important analytical parameters are collected in Table 1. Detailed characteristics of equipment used: sample introduction systems, analyzers and detectors are given. The discussion of experimental parameters, including the choice of analytical wavelengths (ICP-AES) and isotopes (ICP-MS), is presented. The main physical, matrix, chemical and spectral interferences occurring in analysis of real samples are characterized.

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Isolation and analysis of phospholipids

Ostrowska J., Skrzydlewska E., Figaszewski Z. A.

Chemia Analityczna

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2000

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Vol. 45, No. 5

613-629

EN

Different chromatographic methods used for the determination of phospholipids isolated from natural biological membranes have been described. A particular attention is given to the choice of the HPLC technique, and to the separation conditions: stationary phase, composition of mobile phase and detectors.

PL

W artykule dokonano przeglądu literatury na temat izolacji fosfolipidów z błon biologicznych. Szczególną uwagę zwrócono na wykorzystanie do tego celu techniki HPLC, na warunki rozdziału: fazy stacjonarne, skład faz ruchomych oraz detektory.

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HPLC study of the modification of haemoglobin by formaldehyde

Ostrowska J., Roszkowska A., Skrzydlewska E., Figaszewski Z. A.

Acta Chromatographica

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1999

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No. 9

87-96

EN

Formaldehyde is known to react with proteins. The effect of formaldehyde on the total charge and on the tryptic map of haemoglobin has been analysed by HPLC. The effect of methanol intoxication on the total charge of rat haemoglobin was also determined. The total charge of haemoglobin was examined on a Mono Q column by gradient elution with solutions of Tris–HCl and Tris–HCl–NaCl. Tryptic maps were determined on a C18 column by gradient elution with solutions of TFA–water and TFA–acetonitrile–water. Formaldehyde in vitro and methanol intoxication resulted in prolonged retention of haemoglobin. Formaldehyde also reduces the susceptibility of haemoglobin to trypsin hydrolase which leads to a reductions in the magnitudes of peaks in the tryptic map.

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Peptide mapping by high-performance liquid chromatography

Skrzydlewska E., Ostrowska J., Figaszewski Z.

Acta Chromatographica

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1998

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No. 8

70-84

EN

The determination of protein structure by peptide mapping is described in this paper. The method consists in selective fragmentation of the protein molecule with trypsin, separation of resulting peptides by HPLC, and amino acid analysis. Gradient reversed-phase HPLC is performed with 0.1% TFA in water and 0.1% TFA in acetonitrile as mobile phases.