Małgorzata Herman

A standard sample preparation and calibration procedure for imaging zinc and magnesium in rats' brain tissue by laser ablation-inductively coupled plasma-time of flight-mass spectrometry

A calibration procedure consists of several steps, each of which has a significant impact on the final result of the analysis. The preparation of standard samples for analytical calibration is a far more important step in the analytical procedure than it might seem. In this paper, we have discussed a new, innovatory calibration procedure, which is itself a development of one previously published by us concerning a calibration strategy in the determination of trace elements in rat brain tissues by the laser ablation inductively coupled plasma time of flight mass spectrometry (LA-ICP-TOF-MS) method. Moreover, the article has described an important step in the preparation of standard samples, which is both an innovation and exclusive to this work. The linearity of calibration function analysis is fully acceptable (for zinc R = 0.944 and for magnesium R = 0.989), and the applied calibration method, the conventional extrapolative method (CEM), known more generally as the “standard addition method”, makes it possible to avoid interferents from the sample matrix. The results show the usefulness of the procedure developed in the presented analytical problem related to the analysis of solid biological samples. The developed research methodology enabled the preparation of distribution maps of zinc and magnesium in the rats hippocampus, which is a frontier providing unique research in the pathophysiology of a rat brain.

Generalized Calibration Strategy in Analytical Chemistry

A novel calibration methodology named ‘the generalized calibration strategy’ (GCS) is presented that is aimed at verifying and improving the accuracy of analytical determinations. It is based on integration of calibration methods together with such operations as standard addition and sample dilution. At each stage of the sample dilution, the analytical result is estimated on the basis of six values, which are differently resistant to errors caused by interference and non-linearity effects. The process of stepwise elimination of both effects is controlled by comparison of these values. A dedicated flow system is presented. The GCS can be adapted to calibration by all well-known methods: conventional, internal standard, and indirect. This novel calibration strategy has been tested on indirect determination of chlorites in water samples by UV/Vis spectrophotometry.

Complementary dilution method: A new version of calibration by the integrated strategy

Abstract A novel version of the integrated approach to calibration is presented as “the complementary dilution method” (CDM). In the series of six solutions a standard and a sample are suggested to be complementarily diluted with each other and with the blank solution, hence four linear calibration graphs may be constructed on the basis of the measurement data obtained. The analyte concentration in a sample is estimated by four values calculated in both the interpolative and extrapolative way. When comparing statistically these values with one to another, the calibration errors caused by both the non‐linear and interference effect can be detected. The flow injection system designed for realization of the CDM method is presented. The manners how the system can be adapted to examination and elimination of the calibration errors are described. The usefulness and performance of the CDM method have been confirmed experimentally on the examples of the iron determination by UV/VIS spectrophotometry and the calcium and magnesium determination by flame atomic absorption spectrometry.

Essential metals profile of the hair and nails of patients with laryngeal cancer

Trace elements have an impact on numerous physiological processes. The monitoring of their levels in the organism allows you to detect not only their deficiencies, but also several illnesses. The aim of this study was to compare the levels of essential elements (calcium, magnesium, zinc, copper, iron, manganese) in hair, nails and serum of both patients with laryngeal cancer and healthy people. The determination of six metals was performed by an inductively coupled plasma mass spectrometry (ICP-MS) and an inductively coupled plasma optical emission spectrometry (ICP-OES). The concentration of essential elements in hair and nails of the control group was statistically significantly higher than in the group of patients with laryngeal cancer. In the case of serum, differences were found between the patients and controls in respect of the level of three metals. The results of principal component analysis (PCA) revealed the strong and similar clustering behavior of essential elements in hair and nails. The metals did not correlate between two alternative materials. The present study indicated that, using the level of essential elements in hair and nails as a basis, it is possible to distinguish cancer patients from healthy people. The alternative materials are independent of homeostasis and therefore seem to be more useful in the detection of diseases and mineral deficiencies in human than the classical biological materials, such as blood.

Examination of distribution of trace elements in hair, fingernails and toenails as alternative biological materials. Application of chemometric methods

AbstractThe aim of this study was to find correlations between several studied elements and analyzed materials as well as the application and validation of an analytical method to determine trace elements in hair, fingernails and toenails of healthy volunteers (normal concentration). The method developed covers washing, mineralization and ICP-MS determination of 10 elements (Ca, Cd, Co, Cr, Cu, Fe, Mg, Ni, Pb and Zn) in hair and nails. Concentrations of the selected elements in hair, fingernails and toenails were measured for 24 women and 18 men. Furthermore, a chemometric approach (Principal Component Analysis, PCA) was employed to evaluate the correlations between concentrations of the elements in hair and nails and between these materials. Until now PCA has not been frequently applied in handling and interpretation of the results of analysis of biological materials. However, the results of the present investigation show the high potential of PCA in extraction of valuable information from analytical measurements. Additionally, PCA has become a useful tool for visualization of the obtained results. Moreover, the cluster analysis (CA) was used to group the samples according to gender, taking into account two different groups of elements: essential and toxic.

Determination of Cadmium and Lead in Plant Materials by Flow Injection—Flame Atomic Absorption Spectrometry. Elimination of the Matrix Effect in the Preconcentration Step

Abstract The determination of cadmium and lead in plant samples by flame atomic absorption spectrometry with analyte preconcentration in a flow injection system was studied. Preconcentration of Cd and Pb from solution after wet digestion was performed by the use of C18 column, as sorbent, ammonium diethyldithiophosphate (DDPA) at pH = 1 as complexing agent, and methanol as eluent. A strong column clogging effect of the iron and copper was successfully eliminated by the use of masking agents. Oxalic acid 0,4 M and thiourea 0,06 M are sufficient for masking of iron and cooper in solutions obtained after digestion of various plant samples. The enrichment factors obtained at 30 s loading time were 42 for cadmium and 38 for lead. Detection limits (3[sgrave]) were 0,5 μg/l and 4,4 μg/l respectively, for cadmium and lead.

Metal concentrations in hair of patients with various head and neck cancers as a diagnostic aid

Head and neck cancers are one of the most frequent cancers worldwide. This paper attempts to evaluate disturbances of homeostasis of the necessary elements (calcium, magnesium, zinc, copper, iron, manganese) and changes in the levels of toxic metals (lead, cadmium, cobalt, chromium VI) in hair of patients with head and neck cancers, as well as people without a diagnosed neoplastic disease. In order to quantify the necessary elements and toxic metals, a method using ICP-MS and ICP-OES techniques had been developed and validated. The studies have shown that patients with head and neck cancer used to drink alcohol and smoked much more frequently than healthy individuals, both in the past and presently. Statistically significant differences in concentrations of average metal content in the group of patients with head and neck cancers compared to the control group were confirmed. Significant differences in metal content between the group of patients with head and neck cancers and healthy individuals were found which enabled distinguishing between the study groups. To this end, a more advanced statistical tool, i.e. chemometrics, was used. The conducted research analyses and the use of advanced statistical techniques confirm the benefits of using alternative material to distinguish the patients with head and neck cancers from the healthy individuals.

Toxicokinetics and tissue distribution of titanium in ionic form after intravenous and oral administration

Titanium is widely used both in food and cosmetics, as well as in surgery and industry. Contrary to most studies, the present work focused on the determination of the toxicokinetic parameters of titanium in ionic form, as well as on its tissue biodistribution in rats. The animals were administered either a single intravenous dose of 6 mg Ti/kg b.w., or received the same dose orally every day for 30 days. The concentration of titanium in the serum and organs was measured by a graphite furnace atomic absorption spectrometry. Metal rapidly distributed from the circulation to the investigated organs after both routes of administration, and kidney was identified as the main target tissue, followed by liver and spleen. One month of oral exposure to Ti led to the increase of its concentration in liver, kidneys, spleen, and heart. In the intravenous study, both the highest area under concentration-time curves and the longest elimination half-life time were recorded in the kidney followed by serum, spleen and liver. The present study contributes to the knowledge of the toxicokinetics of titanium in ionic form, which may be especially useful when assessing the health risks of long-term exposure to titanium alloy implants in patients.

Toxicological aspects of soluble titanium – a review of in vitro and in vivo studies

Owing to the widespread use of titanium dioxide (TiO2) in various food, household and cosmetic products and in industry, the number of publications concerned with the potential toxic effects and health risks related to this substance in both bulk and nano form is steadily increasing. On the other hand, there is also a third form of titanium, ionic, which is produced by the biodegradation of Ti alloy implants. Thus, the growing population of implant recipients should raise concerns about the impact of soluble Ti on human health. Today, the mechanism of this metals action on the human body is still not fully understood. This review aims to explore the health risks associated especially with long-term use of titanium implants. The paper provides an analysis of data available from the last 10 years concerning investigations of the adverse effects of Ti ions, including in vitro models of various tissues, in vivo studies of implant corrosion in animals and humans, and potential pathomechanisms of the adverse health impact induced by soluble titanium.

Urine as a material for evaluation of exposure to manganese in methcathinone users.

Chronic exposure even to low doses of manganese may lead to development of neurological syndrome similar to parkinsonism. The aim of this research is to assess the possibility of manganese poisoning based on the level of metal in the urine of long-term methcathinone users from Poland. Graphite furnace atomic absorption spectroscopy (GFAAS) was used to determine manganese in urine, while the detection of the psychoactive drugs was performed by high-performance liquid chromatography (HPLC). Results of survey on longitudinal patterns of drug use showed that users of traditional illicit drugs now turn to cheaper alternatives, such as methcathinone. Parkinsonian features were observed in almost half of methcathinone users. The subjects had a higher mean level of Mn in their urine (8.68±9.27 μg L(-1)) than the controls (4.27±1.91 μg L(-1)). The presence of numerous psychoactive substances (in unchanged forms and their metabolites) was confirmed in all of the samples, with only one exception. The elevated level of manganese in urine (in 29.2% of patients) can be used as a primary marker of recent methcathinone administration, especially in the case of long time intravenous drug users where blood sampling is complicated.