Application of ICP-MS for Multielement Analysis in Small Sample Amoun ts of Pathological Thyroid Tissue

 As a result of the Chernobyl nuclear power plant accident in 1986, thyroid pathologies occurred among children in some regions of Belarus. Besides the irradiation of children’s thyroids by radioactive iodine and caesium nuclides, toxic elements from fallout are a direct risk to health. Inductively coupled plasma quadrupole-based mass spectrometry was used for multielement determination in small amounts (1–10 mg) of thyroid tissue samples obtained during thyroid operations in Minsk hospitals. The accuracy of the applied analytical technique for small biological sample amounts was checked using NIST Standard Reference Material oyster tissue (SRM 1566b) and by comparison with independent analytical methods, such as neutron activation analysis. Almost all essential elements as well as a number of toxic elements such as Cd, Pb, Hg, U etc. were determined in a multitude of human and animal thyroid tissues (up to 1 mg sample material) by quadrupole-based ICP-MS using micronebulization. In general, the thyroid tissue affected by pathology is characterized by higher calcium content. Some other elements, among them Fe, Mn, V, As, Cr, Ni, Pb, U, Ba, Sb, were also accumulated in such tissue. The results obtained will be used as initial material for further specific studies of the role of particular elements in thyroid pathology development. Received November 15, 1999. Revision March 15, 2000.     

The concentration of 131I in the thyroid glands of domestic animals

Iodine-131 concentrations in thyroid glands of cows, oxen and swine carried in the Yokohama slauterhouse were measured. The gamma-ray spectral analysis was done with a Ge(Li) detecter. It is considered that 131I in thyroid glands of domestic animals resulted from Chinese open-air nuclear tests and radioactive materials used at medical facilities. It is presumed that 131I from medical facilities was taken in swine thyroid glands from the leaving of meals of patients.     

Determination of microelements in thyroids of the inhabitants of Belarus by neutron activation analysis using thek 0-method

The k ₀-method of neutron activation analysis has been tested for applicability to the determination of trace elements in samples of thyroids of inhabitants from regions in Belarus affected to different degree by thyroid cancer among children after the accident of the Chemobyl power plant. It is shown that thek ₀-method produces results identical to the relative method in neutron activation analysis. Significant differences in the elemental composition of thyroids from the regions of Gomel and Minsk are observed and may be related to the different levels of occurrence of thyroid cancer among children.     

Isotopic ratios of129I/127I in mammalian thyroid glands in Japan

The isotopic ratios of¹²⁹I/¹²⁷I in cattle thyroid glands collected from various areas of Japan were measured by neutron activation analysis with combustion pre-treatment. Pig and human thyroid glands were also analyzed by the same method. The iodine isotopic ratio in cattle thyroid glands in Japan is comparable with that observed in Europe. The isotopic ratio in human thyroid glands in Japan is remarkably lower than that in Europe, which has been reported to be comparable to that of cattle. The isotopic ratio in pig thyroid glands is also lower than that in cattle.     

Long-Lived Radioiodine in Japanese Environment

The amount of long-lived radioiodine, ¹²⁹I (half-life 1.57·10⁷ y) in the Japanese environment has been studied by measuring thyroids of humans and animals. The collected samples were thyroids of (1) humans in Ibaraki Prefecture, in Kanto district, the central part of Japan, (2) cattle in Aomori Prefecture, north part of Japan, and (3) wild deer in Chiba Prefecture, in Kanto district. The measured mean isotopic ratio ¹²⁹I/¹²⁷I for thyroids of cattle in Aomori Prefecture is 3.5±1.8·10^-9. A higher value of 14±5·10^-9 has been obtained for thyroids of wild deer in Kanto district. On the other hand, the measured ratio for human thyroids in Kanto district is 1±0.2·10^-9. This value is significantly lower than that of cattle thyroids in Aomori and also those reported for human thyroids in Europe and USA. The higher mean ratio for cattle thyroid in Kanto district is possibly explained by the influence of nuclear reprocessing plant. Lower mean ratio for human thyroid might be due to higher dietary intake of algae.     

A search for losses of chemical elements during freeze-drying of biological materials

Possible losses of seven chemical elements were investigated in biological tissues during freeze-drying in vacuum. Thyroid glands were taken during post-mortem examination of 23 people died of different diseases. Instrumental neutron activation analysis (INAA) was used to estimate contents of Br, Ca, Cl, I, K, Mg, and Na. The nuclear reator vertical channel with flux density of 1.2·10¹³n·cm^–2·s^–1 was used for neutron irradiation. The analysis was carried out using short-lived radionuclides induced in samples after neutron irradiation. Then thyroids were freeze-dried at below 0 °C in vaccum up to the constant mass (lyophilisation) and then homogenized. Samples of lyophilised and homogenized tissues were again studied by INAA. The lack of difference between the results of the analysis before and after lyophilisation is an evedence of no loss of Br, Ca, Cl, I, K, Mg and Na during freeze-drying of biotissues in vaccum.     

In vivo X-ray fluorescent analysis of iodine concentration in the thyroid (author's transl)

A simple apparatus was made for the X-ray fluorescent analysis of iodine concentration of the thyroid. The apparatus consists of 241Am gamma-ray source of 300mCi and pure Ge detector of 50mm2X5mm. Diverging collimator was designed to achieve a full view of the thyroid. The detectable concentration was 0.2mg iodine/g tissue assuming the coefficient of variance of 30% and the counting time of 5 minutes. Measurement was performed for autopsied 10 thyroids and the results were in good correlation with those by neutron activation analysis (r=0.93). Iodine concentration ranged 0.3-1.2mg/g (mean 0.6mg/g) and compared well with the data in literatures. This technique is useful for the in vivo measurement of thyroidal iodine content in patients.     

New human hair certified reference material for methylmercury and trace elements

A new human hair certified reference material (NIES CRM No. 13) for mercury speciation and trace element analysis was prepared at the National Institute for Environmental Studies (NIES), Environmental Agency of Japan. Scalp hair from Japanese males, which is identical with the original material for the previous human hair CRM (NIES CRM No. 5), was used. Special attention was paid to reduce contamination from a grinding vessel during the preparation procedure. A newly-prepared ceramic/Teflon disc mill was used for cryogenic grinding of the hair. 1, 000 bottles (3 g each) were produced after sieving and blending of the hair powder. Certified values for total mercury and methylmercury, as well as other trace elements of toxicological and nutritional significance (antimony, cadmium, copper, lead, selenium, and zinc), were determined based on analyses from extensive collaborations. Reference values for 12 elements (aluminium, arsenic, barium, calcium, cobalt, iron, magnesium, manganese, silver, sodium, sulfur and vanadium) were also given.     

Enhanced ALA-induced fluorescence in hyperparathyroidism

INTRODUCTION: Intraoperative localization of parathyroid glands can be challenging especially in minimally invasive surgery. Fluorescence diagnosis using the photosensitizer aminolevulinic acid (ALA) has been described to identify normal parathyroid glands during experimental bilateral neck exploration. The present study evaluated fluorescence differences between hyperplastic and normal parathyroid glands as a precondition for a clinical application of the technique. MATERIALS AND METHODS: Polycystic kidney disease (PKD) rats with hyperparathyroidism due to hyperplastic parathyroid glands and Wistar rats with normal parathyroid glands were photosensitized by peritoneal lavage with ALA solution. After surgical exposure of thyroid and parathyroid glands the operative site was observed under blue light conditions using the d-light system to assess fluorescence characteristics of each tissue. Fluorescence intensities of parathyroid glands and surrounding thyroid tissue were measured by spectrometry. Parathyroid hormone in serum of the rats was determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: Observation of the exposed thyroid site showed a subjectively stronger red fluorescence of the parathyroid glands in the PKD rats in comparison to the Wistar rats, whereas thyroid tissue appeared equally fluorescent. In the PKD animals, spectrometric fluorescence intensity was 10 times higher in the parathyroid glands than in the thyroid gland, whereas in the Wistar rats the ratio was 3.2:1. Fluorescence intensity in the parathyroid glands was more than twice in the PKD rats than in the Wistar rats, however slightly lower in the thyroid tissue. ELISA confirmed the pathophysiological change of a hyperparathyroidism with significantly increased serum levels of parathyroid hormone in the PKD rats. DISCUSSION: Hyperparathyroidism enhances ALA-induced fluorescence of the parathyroid glands. A combined surgical fluorescence strategy may justify a unilateral, minimally invasive approach in selected patients and serve to improve the capability of the surgeon to safely and efficiently manage parathyroid diseases.     

New human hair certified reference material for methylmercury and trace elements

 A new human hair certified reference material (NIES CRM No. 13) for mercury speciation and trace element analysis was prepared at the National Institute for Environmental Studies (NIES), Environmental Agency of Japan. Scalp hair from Japanese males, which is identical with the original material for the previous human hair CRM (NIES CRM No. 5), was used. Special attention was paid to reduce contamination from a grinding vessel during the preparation procedure. A newly-prepared ceramic/Teflon disc mill was used for cryogenic grinding of the hair. 1,000 bottles (3 g each) were produced after sieving and blending of the hair powder. Certified values for total mercury and methylmercury, as well as other trace elements of toxicological and nutritional significance (antimony, cadmium, copper, lead, selenium, and zinc), were determined based on analyses from extensive collaborations. Reference values for 12 elements (aluminium, arsenic, barium, calcium, cobalt, iron, magnesium, manganese, silver, sodium, sulfur and vanadium) were also given. Received: 8 February 1996/Accepted: 4 April 1996     

Water soluble calixarenes as possible metal ion extractants in polyethylene glycol-based aqueous biphasic systems

The iodine thyroid content of 57 relatively healthy men and women 14–60 years old was studied using instrumental neutron activation analysis. Two methods were used: analysis of whole glands and the analysis of lyophilized samples weighing 50 mg each. Very good agreement between results was obtained. It was shown that the total iodine content, concentration and weight did not depend on age and sex. The typical mean thyroid parameters were found for healthy people of non-endemically goitrous regions where iodated food is not eaten. Average thyroid weight was 14.2g, iodine concentration was 350 g/g of wet weight and thus total iodine content was 5 mg.     

Multi-element neutron activation analysis measurements towards the geochemistry of particulate matter exchange between continent—Atmosphere—Ocean

Sampling of marine aerosol and ocean water particulate matter yields very small quantities of material. INAA is used for routine analysis since it provides measurements of as many as 25 elements and permits multiple use of the small samples. Results are given for the mean elemental composition of Atlantic marine aerosols and oceanic suspended matter. Such analyses are essential for the interpretation of global geochemical cycles.     

Multielement analysis with ICP-AES-possibilities for quality control with CRMs

Summary An analysis using Certified Reference Materials (CRMs) together with routine samples is by far the best approach for quality control in multielement analysis of environmental samples. The selection of the correct CRM is thus the first important step for all reliable analysis. The chosen material should have a similar matrix, similar concentration of the element(s) of interest and a sufficient number of well-certified elements. For the analysis of samples from the Environmental Specimen Bank only a few CRMs could be successfully used. These were analyzed for a considerable period of time, together with the routine samples for quality control. The results of these analyses were compared with the certified values.     

Study of human neutrophil peptides in saliva by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry

Matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) mass spectrometry is used to rapidly characterize the human neutrophil peptides – HNP 1, 2, and 3 – in saliva. The saliva excreted from the parotid and sublingual/submandibular glands of 70 individuals were collected and examined using MALDI‐TOF. The MALDI approach requires no sample pretreatment other than mixing the saliva‐absorbing material with the matrix and drying under ambient conditions. Tissue paper was the best material for collecting the saliva samples because of its strong texture and high absorbance, and sinapinic acid was the best MALDI matrix for the analysis of the HNPs. HNPs were detected in almost all the samples collected from the parotid glands, with no obvious differences among age or gender. In contrast, the distribution of the HNPs in the samples collected from the sublingual/submandibular glands was age‐dependent: no HNPs were detected for those collected from individuals younger than 30, but the HNPs were present in all of the samples collected from those older than 60 years. The increased probability of detecting saliva HNPs with age suggests that HNPs may function as a biomarker for aging. Copyright © 2009 John Wiley & Sons, Ltd.     

Application of SEC-ICP-MS for comparative analyses of metal-containing species in cancerous and healthy human thyroid samples

Size exclusion chromatography (SEC) was coupled on-line to inductively coupled plasma mass spectrometry (ICP-MS) for speciation study of trace metals in cancerous thyroid tissues in comparison to healthy thyroids aimed to estimation of changes in metalloprotein speciation in pathological tissue. The study showed a presence of species binding Cu, Zn, Cd and Pb in healthy thyroid tissue with a good reproducibility of chromatographic results, whereas the same species could not be detected in cancerous tissues. Thus, remarkable differences with respect to metal-binding species were revealed between healthy and pathological thyroid samples, pointing out a completely different distribution of trace metals in cancerous tissues. The metal-binding species could not be identified in the frame of this work because of a lack of appropriate standards. Nevertheless, the results obtained confirm the suitability of SEC-ICP-MS for monitoring of changes in trace metal distribution in cancerous tissue and will help to better understand the role of metal-containing species in thyroid pathology.     

Reversed-phase high-performance liquid chromatographic characterization of acetic acid extracts of the normal and the diabetic human pancreas

The combination of a divinylbenzene-based reversed-phase (RP) column and acetic acid gradients in water as mobile phase described in the accompanying paper was used for characterizing the extractable polypeptides from the normal and the diabetic human pancreas. The pancreas was lyophilized, minced and extracted three times in 3 M acetic acid. After mechanical clarification, the raw extracts were applied directly to the RP column. Alternatively, the extracts were lyophilized and subjected to size-exclusion chromatography on Sephadex G-50 in 3 M acetic acid. Two fractions with mol. wt. greater than 6000 dalton (Peak I) or with mol. wt. less than or equal to 6000 dalton (Peak II) were obtained. The Sephadex G-50 size-exclusion chromatography and the RP-high-performance liquid chromatographic (HPLC) analyses of the crude extracts from a normal pancreas clearly demonstrated the weight distribution and differences between the exocrine pancreas (containing primarily the major digestive enzymes) and the endocrine pancreas (containing insulin, glucagon, etc.). RP-HPLC analyses of crude extracts from various normal pancreatic glands resulted in very similar UV profiles, whereas those from a number of individual diabetic glands differed. Chromatograms of acetic acid extracts from normal pancreata were similar when analysed before or after lyophilization, whereas lyophilization of acetic acid extracts of diabetic glands resulted in severely obscured chromatograms. RP-HPLC analyses clearly demonstrated several differences between the diabetic and the normal pancreas. In the crude extracts, the extractable proteins from the diabetic pancreas were shifted towards lower molecular weight and/or hydrophobicity. Further, a peak co-eluting with authentic, human insulin could be demonstrated in the raw extract and in the peak II material from the normal pancreas, whereas virtually no mass signal was seen in the UV-profiles of similar materials from the diabetic gland. This finding was further verified by insulin radioimmunoassay (RIA) performed on the isolated fractions after RP-HPLC of a crude extract from a normal and a diabetic pancreas. The insulin content in the diabetic pancreas was found to be ca. 1% of that in the normal pancreas. When authentic glucagon was added to crude extracts from a diabetic pancreas, a single component was found after immediate analysis, but after several hours at room temperature the glucagon was found to be degraded. Added insulin was stable under these conditions. Similar RP analyses were performed on a silica C4 column eluted with an acetonitrile gradient in trifluoroacetic acid.(ABSTRACT TRUNCATED AT 400 WORDS)     

Radioiodine tracers as useful tools in studies of thyrotoxic effects of exogenous bromide and perchlorate ions

With the use of ¹²⁵I and ¹³¹I radionuclides, we followed the effects of exogenous bromide and perchlorate ions on the metabolism of iodine and of thyroid hormone in the rat. The presumed thyrotoxic effects of bromide and perchlorate have been confirmed and quantified. Correct assay conditions for the radiometric determination of the enzyme activity of thyroid peroxidase (TPO) have been established. The use of the adapted radiometric assay revealed a divergent influence of bromide and perchlorate ions on the TPO activity in the rat thyroids. Excessive bromide exerted a biphasic effect, depending on the extent of bromide intake in the animals. In contrast, in all the rats that were administered with high amounts of perchlorate were found elevated TPO activities.     

Quasi ‘non-destructive’ laser ablation-inductively coupled plasma-mass spectrometry fingerprinting of sapphires

A homogenized 193 nm excimer laser with a flat-top beam profile was used to study the capabilities of LA-ICP-MS for ‘quasi’ non-destructive fingerprinting and sourcing of sapphires from different locations. Sapphires contain 97–99% of Al₂O₃ (corundum), with the remainder composed of several trace elements, which can be used to distinguish the origin of these gemstones. The ablation behavior of sapphires, as well as the minimum quantity of sample removal that is required to determine these trace elements, was investigated. The optimum ablation conditions were a fluency of 6 J cm⁻², a crater diameter of 120 μm, and a laser repetition rate of 10 Hz. The optimum time for the ablation was determined to be 2 s, equivalent to 20 laser pulses. The mean sample removal was 60 nm per pulse (approx. 3 ng per pulse). This allowed satisfactory trace element determination, and was found to cause the minimum amount of damage, while allowing for the fingerprinting of sapphires. More than 40 isotopes were measured using different spatial resolutions (20–120 μm) and eight elements were reproducibly detected in 25 sapphire samples from five different locations. The reproducibility of the trace element distribution is limited by the heterogeneity of the sample. The mean of five or more replicate analyses per sample was used. Calibration was carried out using NIST 612 glass reference material as external standard. The linear dynamic range of the ICP-MS (nine orders of magnitude) allowed the use of Al, the major element in sapphire, as an internal standard. The limits of detection for most of the light elements were in the μg g⁻¹ range and were better for heavier elements (mass >85), being in the 0.1 μg g⁻¹ range. The accuracy of the determinations was demonstrated by comparison with XRF analyses of the same set of samples. Using the quantitative analyses obtained using LA-ICP-MS, natural sapphires from five different origins were statistically classified using ternary plots and principal multi-component analysis.     

Characterization of NIES CRM No. 23 Tea Leaves II for the determination of multielements

A candidate environmental certified reference material (CRM) for the determination of multielements in tea leaves and materials of similar matrix, NIES CRM No. 23 Tea Leaves II, has been developed and characterized by the National Institute for Environmental Studies (NIES), Japan. The origin of the material was tea leaves, which were ground, sieved through a 106-μm mesh, homogenized, and then subdivided into amber glass bottles. The results of homogeneity and stability tests indicated that the material was sufficiently homogeneous and stable for use as a reference material. The property values of the material were statistically determined based on chemical analyses by a network of laboratories using a wide range of methods. Sixteen laboratories participated in the characterization, and nine certified values and five reference values were obtained. These property values of the candidate CRM, which are expressed as mass fractions, were close to the median and/or mean values of the mass fractions of elements in various tea products. The candidate CRM is appropriate for use in analytical quality control and in the evaluation of methods used in the analysis of tea and materials of similar matrix.