Coupled Plasma Mass Spectrometry Method Research Articles

Investigation of toxic heavy metals content and estimation of potential health risks in Chinese herbal medicine

The content of toxic heavy metals (THMs), including lead (Pb), arsenic (As), cadmium (Cd), and mercury (Hg), was determined in a total of 10,245 samples for 279 types of Chinese herbal medicine (CHM) using a validated inductively coupled plasma mass spectrometry method. The exceeding rate (ER) for the four THMs were calculated based on diverse permissible limits (PLs) established by different organizations and national pharmacopeias. Cluster analysis was used to classify the degree risk of THMs contamination according to the calculated ER. Results revealed that Cibotii rhizome, Selaginellae herba, Morindae officinalis radix, Asprellae ilicis radix, and Toxicodendri resina exhibited high-degree risk of Pb contamination. Eckloniae/Laminariae thallus, Spirodelae herba, and Naturalis indigo possessed high-degree risk of As contamination. Tetrapanacis medulla, Centipedae herba, Cyathulae radix, Linderae radix, Meretricis/Cyclinae concha, and Tabanus displayed high-degree risk of Cd contamination. Toxicodendri resina has high-degree risk of Hg contamination. In addition, six types of CHM, including Asprellae ilicis radix, Toxicodendri resina, Eckloniae/Laminariae thallus, Fossilia Ossis Mastodi, Haematitum, and Hedyotidis diffusae herba, may have non-carcinogenic health risk after consumption of raw materials because the calculated hazard quotient and hazard index were over 1.0. In summary, these data provide useful information about THMs contamination in CHM.

Development and Validation of an Inductively Coupled Plasma Mass Spectrometry Method for Estimation of Elemental Impurities in Calcium Acetate Active Pharmaceutical Ingredient

A sensitive and selective method has been developed and validated for the simultaneous quantitative estimation of aluminum, magnesium, potassium, strontium and sodium in calcium acetate active pharmaceutical ingredient by inductively coupled plasma mass spectrometry. Inductively coupled plasma mass spectrometry is an advanced technique which is capable of analyzing multiple elements simultaneously with high selectivity, sensitivity and much lower detection limit. The test sample was prepared with microwave assisted acid digestion and introduced into optimized instrumental parameters for use of a quadrupole based Agilent 7800 inductively coupled plasma mass spectrometry instrument. Scandium is used as an internal standard in the study. The developed method was validated in terms of specificity, linearity, accuracy, precision, range, limit of detection, limit of quantitation and ruggedness. The results for recoveries of all elements were found between 85.3 to 103.9 %. The relative standard deviation for precision was within 15 %. Calibration plots were linear. The low relative standard deviation values and high recoveries of the method confirm the suitability of the method.

AURUM POLYACRYLATE: THE EXPERIMENTAL STUDY OF THE ANTITUMOR ACTIVITY

Introduction. The investigation of metal substituted organic compounds as potential antitumor drugs is one of the promising areas of research in experimental and clinical oncology.Objective. The pre-clinical study of the original antitumor drug aurum polyacrylate (aurumacryl) which belongs to such new for oncology group of compounds as polyacrylates of metals was the aim of this work.Materials and methods. Aurumacryl antitumor activity was determined as the tumor growth inhibitory effect against some of the murine solid tumors (Lewis lung carcinoma, Acatol adenocarcinoma and Ca-755 adenocarcinoma). Drug cytotoxic effect against some of the human tumor cells (Mel-Mo melanoma, A549 lung carcinoma, MCF-7 breast carcinoma, HCT116 colon adenocarcinoma) was evaluated with standard МТТ-test. The aurumacryl pharmacokinetics in tumor bearing mice (Lewis lung carcinoma) was studied. The inductively coupled plasma mass spectrometry method was used for the estimation of the aurum maintenance in the tested tissues (tumor, blood, kidneys, liver, lungs, spleen, brain).Results. The 80–90 % tumor growth inhibitory effect of aurumacryl against some solid tumors in mice had been revealed in vivo as well as the death of the 60–90 % human tumor cells of various origins in vitro. Beside this the strong decrease of the number of proliferating MCF-7 tumor cells had been shown. The distribution of aurumacryl in the body of the mice with the solid tumor had been revealed.Conclusion. On the base of the data obtained the further study of the aurumacryl as a potential antitumor agent seems rather promising.

Occurrence forms of rare earth elements in coal and coal gangue and their combustion products

Distribution of rare earth elements (REEs) in six speciations extracted from coal and coal gangue and their combustion products (slag and fly ash) generated by three different power plants in China were determined by sequential extraction procedure combined with inductively coupled plasma mass spectrometry method. The results show that the REEs mainly occurred as acid soluble and silicate & aluminosilicate fraction, e.g., approximately 42.54% and 45.62% in coal gangue, 32.85% and 57.13% in lignite, and 18.10% and 75.46% in bituminous coal, respectively. However, REEs in the combustion products were mainly presented in silicate & aluminosilicate fraction regardless of coal or coal gangue, reaching up to approximately 80% of the total REEs content. During combustion, around 36%, 23%, and 5% from the other five fractions (water soluble, ion-exchangeable, acid soluble, organic, and sulfide) were transformed to silicate & aluminosilicate fraction from coal gangue, lignite, and bituminous coal, respectively. In the case of coal or coal gangue, the amount of each REEs in the same extracted fraction was different, but the distribution trend of REEs from La to Lu in each fraction was followed in the same rule. In the case of slag and fly ash generated from coal or coal gangue, distribution of REEs from La to Lu in each fraction showed the different trend between fly ash and slag. This was due to the fly ash exposed in flue gas system was much longer than the time for slag formation.

Thermodynamic and kinetics investigation of elemental evaporation from molten Al7Si4Cu alloy

Treatment of liquid aluminum alloys in low vacuum conditions is often applied for parts production in the automotive and aerospace industry because of its effectiveness in removing dissolved gases. Because of the low vapour pressure of aluminum, concentrations of the most unwanted elements can be significantly reduced at lower pressures. Presented work analyzing kinetics parameters for elemental evaporation from liquid Al7Si4Cu alloy. The pressure inside mullite refractory material was below 2.1 kPa for melt temperatures between 760 and 910 °C. The alloy’s chemical composition was characterized by the Inductively Coupled Plasma Mass Spectrometry method. Lead, Zinc, and Mercury were reduced at the highest rate while the lowest evaporation occurred for key alloying elements such as Silicon and Copper. Higher evaporation rates were achieved at higher temperatures. The evaporation ratios, volatility coefficients, reaction rate constants, mass transfer coefficients, and elemental evaporation susceptibility on temperature increase were deduced for 16 elements. The obtained results confirmed that keeping molten aluminum alloys in low vacuum conditions for one hour is an efficient method in removing unwanted elements with great potential for further improvement in industrial conditions.

Mercury in samples of gas mixtures – a review of mercury sampling and determination methods

The determination of the composition of gas mixtures, especially those analytes which exist, for example, as contaminants for the main components of the gas mixture, very often requires the concentration of the analyte so that it can be quantified. The analysis of gaseous environmental samples, including air and air samples at workplaces, is difficult, which results from: the need to work with samples with an extensive matrix and heterogeneous distribution of pollutants, the stability of the analyte and the presence of interfering substances (interferents) in the sample. On the other hand, the analysis of trace components of gaseous fuels is difficult due to the need to collect a suitably concentrated sample so that these components can be quantified. This article provides an overview and analysis of the methods used for the collection and determination of mercury in gas mixtures. Currently, there are standardized mercury collection and determination methodologies dedicated to matrices such as air, workplace air, waste gases or natural gas. These are both manual and fully automated methods. Most of the methods described in the literature on the subject consist of two stages, i.e. the stage of collecting a sample for a solid or liquid sorbent and the stage of desorption and determination of the mercury content in the collected sample using methods dedicated to the analysis of this element. The most frequently used methods for collecting mercury samples in gas mixtures are: the gold amalgamation method and the sorption methods on powder sorbents (such as activated carbon, hopcalite, impregnated silica gel), glass fibers, impregnated cellulose filters and liquid sorbents (such as e.g. acids). The methods of sample desorption are varied and depend on the material on which the analyte has been absorbed and the selected mercury determination method. Three methods are mainly used to analyze samples for mercury content, i.e. the cold vapor atomic absorption spectrometry method (CV-AAS), the cold vapor fluorescence atomic spectrometry method (CV-AFS) and the inductively coupled plasma mass spectrometry method (ICP-MS). However, it should be kept in mind that although the methods available and used for the analysis of mercury content in gas are standardized, they are not resistant to the presence of hydrocarbons and hydrogen sulphide in the tested samples. These are the compounds that are most often mentioned as substances interfering in the determination of mercury in gases using the above-mentioned methods.

Personal exposure to PM2.5-bound heavy metals associated with cardiopulmonary function in general population.

To better understand the cardiopulmonary alterations associated with personal exposed PM2.5-bound heavy meals, we conducted a cross-sectional study in 2018 on 54 general residents. For each subject, PM2.5 exposure filter was collected by a low-volume sampler for 24h; blood and urine samples were collected subsequently. Heavy metals in PM2.5, blood, and urine samples were determined by inductively coupled plasma mass spectrometry method. PM2.5-bound Mn, Cd, Sb, Pb, and Ni levels were 20.5, 9.27, 9.59, 28.3, and 16.9ng/m3, respectively. The distribution of these metals followed the order: Pb (33.47%) > Mn (24.24%) > Ni (19.99%) > Sb (11.34%) > Cd (10.96%). The distribution of heavy meals in PM2.5, blood, and urine differed from each other. PM2.5-bound Cd, Pb levels were positively correlated with blood Cd, Pb levels (r= 0.323, r= 0.334, p< 0.05), respectively. PM2.5-bound Cd level was significantly higher in smoking group than non-smoking group (28.8 vs. 7.27ng/m3, p< 0.01), same as Sb level (12.0 vs. 9.34ng/m3, p< 0.01). Cd and Pb exposure might interact with cardiovascular function through autonomic regulation. No significant correlation was observed between metal exposure and pulmonary function. In conclusion, our data suggested that personal exposure to specific PM2.5-bound heavy metals might interact with profound cardiovascular alterations.

Pengaruh Media Perebusan Terhadap Komposisi Mineral Kerang Air Tawar Meti (Batissa violacea Lamarck, 1818)

This research aims were to analyzed mineral composition of fresh and processed meti freshwater mussels (Batissa violacea Lamarck,1818) and to know the effect of boiling media on the mineral composition with various added boiling media conditions that are water, NaCl 1%, and acetic acid 0.5%. Mineral compositions were tested with microwave digestion and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) method. Mineral composition of fresh mussel were consisted of calcium (Ca) 10412 mg/kg, cobalt (Co) 0,182 mg/kg, copper (Cu) 3,54 mg/kg, magnesium (Mg) 345 mg/kg, mangan (Mn) 13,6 mg/kg, phosphor (P) 7753 mg/kg, potassium (K) 1163 mg/kg, sodium (Na) 291 mg/kg, and zinc (Zn) 44,2 mg/kg. The results of research on freshwater mussels in boiling media of water, NaCl 1%, and acetic acid 0.5% gave effect on the levels of minerals of calcium (Ca), magnesium (Mg), phosphor (P), potassium (K), sodium (Na ), cobalt (Co), copper (Cu), mangan (Mn) and there is no effect on the levels of zinc (Zn).

Application of μ-TLC for speciation of inorganic arsenic by laser ablation inductively coupled plasma mass spectrometry

A novel µ-Thin layer Chromatography coupled with Laser Ablation Inductively coupled Plasma Mass Spectrometry method based on Ion Imprinted Polymer (IIP) is developed for the first time in this paper which tries to investigate the separation of inorganic arsenic species in aqueous media. Surface morphology, functionality, and bulk composition of the as-synthesized copolymer were confirmed utilizing multiple techniques, such as XRD, FESEM, and FT-IR. IIP-Copolymer was combined with CaSO4, as a binder agent, that was used to prepare a thin layer chromatography plate. Subsequently, inorganic arsenic species were separated over the TLC plate based on As(V)-imprinted polymer. In the following, the plate surface was scanned via laser ablation which volatilized the inorganic arsenic species from the TLC plate and then introduced them to the ICP-MS system. The effect of some experimental conditions including pH, mobile phase composition, and IIP/CaSO4 mass ratio on the separation efficiency were also investigated. Moreover, the obtained results for the spiked inorganic arsenic species in real samples, such as Angouran, Nakhlak, and Zarshouran proved that the methods were practically applicable to speciation analysis. Under the established optimal condition, the detection limit, Relative Standard Deviation (RSD) of responses, and linear dynamic range (LDR) of the method were obtained as 0.3 μg L−1, 3.8%, and 0.2–100 μg L−1 for As(V) assay. The IIP-µTLC/LA-ICP-MS has also illustrated great application perspectives for rapid and high-effective selection, characterization, and separation of ultra-trace inorganic arsenic species in environmental water samples.

Food Fingerprinting: Using a Two-Tiered approach to Monitor and Mitigate Food Fraud in Rice.

Rice is an important staple food that is consumed around the world. Like many foods, the price of rice varies considerably, from very inexpensive for a low-quality product to premium pricing for highly prized varieties from specific locations. Therefore, like other foods it is vulnerable to economically motivated adulteration through substitution or misrepresentation of inferior-quality rice for more expensive varieties. In this article we describe results of a research project focused on addressing potential food fraud issues related to rice supplies in China, India, Vietnam, and Ghana. Rice fraud manifests differently in each country; therefore, tailored solutions were required. Here we describe a two-tiered testing regime of rapid screening using portable Near Infrared technology supported by second tier testing using mass spectrometry-based analysis of suspicious samples. Portable Near Infrared spectroscopy models and laboratory-based Gas Chromatography-Mass Spectrometry methods were developed to differentiate between: high-value Basmati rice varieties and their potential adulterants; six Geographic Indicated protected rice varieties from specific regions within China; various qualities of rice in Ghana and Vietnam; and locally produced and imported rice in Ghana. Furthermore, an Inductively Coupled Plasma-Mass Spectrometry method was developed to support the Chinese rice varieties methods as well as a Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry method for quality differentiation in Vietnam. This two-tier approach can provide a substantially increased level of testing through rapid screening outside of the laboratory with the reassurance of corroborating mass spectrometry-based laboratory analysis to support decision making.

Influence of sample surface topography on laser ablation process

In this work we discuss how sample surface topography can significantly influence the laser ablation (LA) process and, in turn, the analytical response of the LA Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) method. Six different surface topographies were prepared on a certified aluminium alloy sample BAM 311 and SRM NIST 610 to investigate the phenomenon. All the samples were repetitively measured by LA-ICP-MS using a spot by spot analysis. The effect of laser fluence in the range of 1–13 J/cm2 was studied. For majority of measured isotopes, the ICP-MS signal was amplified with roughening of the sample surface. A stronger effect was observed on the Al alloy sample, where the more than sixty-time enhancement was achieved in comparison to the polished surface of the sample. Since the effect of surface topography is different for each analyte, it can be stated that surface properties affect not only the ICP-MS response, but also elemental fractionation in LA. The presented results show that different surface topographies may lead to misleading data interpretation because even when applying ablation preshots, the signal of individual elements changes. The utmost care must be taken when preparing the surface for single shot analysis or chemical mapping. On the other hand, by roughening the sample surface, it is possible to significantly increase the sensitivity of the method for individual analytes and supress a matrix effect.

Assessment of potentially harmful elements in floodplain soils and stream sediments in Ile-Ife area, South-western Nigeria

The enrichment of potentially harmful elements (PHEs) in stream sediments (SS) and floodplain soils (FS) poses great environmental hazards to water bodies and other parts of the ecosystem. The aim of this research was to evaluate the distribution pattern of selected PHEs (Cu, Pb, Zn, Co, Mn, As, Cd, V, Cr, Ni, Th, Sr and La) in SS of selected rivers that drain Ile-Ife area and their adjacent FS, to ascertain the pollution status of these elements in the study area. Sixty samples (40 SS and 20 FS) were purposely collected for this study; the samples were analysed with ultra-trace inductively coupled plasma mass spectrometry method (ICP-MS). The PHEs results showed decreasing trend of average contents of PHEs studied; Mn > Zn > V > Cr > Pb > La > Sr > Cu > Ni > Co > Th > As > Cd for both SS and FS. Also, PHEs concentration in the studied geo media showed a significant level of enrichment as observed from the results. Elemental association showed positive correlation for topsoil, Pb/Zn = R2, 0.85 and negative correlation for topsoil Cr/Zn = R2 0.02 among the other PHEs. Source apportionment showed that the studied metal enrichment is largely anthropogenic rather than geogenic. Geoaccumulation and metal ratio indexes indicated that FS and SS studied have received significant PHEs of between moderately to strongly polluted, which implies significant environmental implications in the study area.

Higher toenail selenium is associated with increased insulin resistance risk in omnivores, but not in vegetarians

BackgroundThe relationship between selenium (Se) and insulin resistance remains unclear. We aim to explore the association between toenail Se levels and insulin resistance through a cross-sectional study comprising Chinese vegetarians and matched omnivores.MethodsIn this study, we enrolled 220 vegetarians and 220 omnivores matched by age and sex from Shanghai. The inductively coupled plasma mass spectrometry method was used to measure toenail Se levels. Dietary Se intakes were assessed by the 24-h dietary recall method. Blood samples were collected to measure fasting blood glucose level and fasting insulin concentrations. Insulin resistance index (HOMA-IR) and insulin secretion index (HOMA-B) were calculated to evaluate insulin resistance. Multi-linear regression analysis was performed to determine the association between toenail Se levels and insulin resistance, after adjusting for confounders.ResultsThe mean ages of vegetarians (76 vegans, 144 lacto-ovo-vegetarians) and omnivores were 35.96 ± 8.73 years and 35.23 ± 8.93 years, respectively. Of these, 180 (81.8%) were female and 40 (18.2%) were male. No association was found between toenail Se levels and insulin resistance in vegetarians. However, the concentration of Se in toenails was positively correlated with fasting insulin levels (β = 1.030, 95%CI: 0.393 to 1.667) and HOMA-IR (β = 0.245, 95%CI: 0.098 to 0.392) in omnivores, after multivariate adjustment for age, sex, BMI, alcohol consumption, income, and daily dietary intakes (energy, protein, fat, carbohydrate, and fiber). This positive relationship persisted only in omnivores whose dietary Se intake was above 60 μg/d.ConclusionsHigher toenail Se levels were associated with increased insulin resistance risk in Chinese omnivores whose dietary Se intake was above 60 μg/d, but not in vegetarians. These findings create awareness on the association of dietary Se intake above 60 μg/d with the risk of insulin resistance.

Monitoring of toxic heavy metals contamination in commonly used Chinese materia medica

Monitoring of toxic heavy metals (THMs) contamination, including lead (Pb), arsenic (As), cadmium (Cd), and mercury (Hg), for the quality control in Chinese materia medica (CMM) is critical for ensuring safe medication use in the pharmaceutical industry. A validated inductively coupled plasma–mass spectrometry method was used to determine THMs content in 1887 samples for 27 selected types of commonly used CMM. The correlation coefficient of the calibration curves for four THMs was higher than 0.995, indicating that the linearity is fine. The recovery rate was ranged in 82.6–105.4% for four THMs. The percentage of RSD in inter-day and intra-day precision test for four THMs was all lower than 10%. The limit of quantitation in test solution for Pb, As, Cd and Hg was 0.212, 0.500, 0.038, 0.044 μg/L, indicating that this validated ICP-MS method exhibited excellent sensitivity. Among these THMs, Pb and Cd are the most abundant contaminants in 27 selected types of CMM. In diverse permissible limits (PL) established by different countries/organizations, Cinnamomi ramulus and Eucommiae cortex usually exceeded the PL of 0.3 μg/g for Cd and occasionally exceeded the PL of 5.0 μg/g for Pb. Chuanxiong rhizome seldom exceeded the PL of 1.0 μg/g for Cd. Eucommiae cortex, Raphani semen, Atractylodis macrocephalae rhizoma and Bupleuri radix occasionally exceeded the PL of 0.3 μg/g for Cd. In conclusion, we hope to raise awareness of THMs contamination in commonly used CMM that affects safe medication use among farmers, manufacturer, and consumers.

Consequences of Iodine Deficiency and Excess in Pregnancy and Neonatal Outcomes: A Prospective Cohort Study in Rio de Janeiro, Brazil.

Background: Insufficient or excessive iodine intake during gestation may compromise adaptive mechanisms in maternal thyroid function and lead to adverse pregnancy outcomes. In this context, we aimed to study the effects of maternal iodine status in the first and third trimesters of gestation on obstetric and neonatal outcomes in an iodine-sufficient population in Rio de Janeiro, Brazil. Methods: A total of 214 pregnant women in the first trimester of gestation were enrolled and prospectively followed until delivery between 2014 and 2017. All participants were ≥18 and ≤35 years, had a spontaneous single pregnancy, and had no history of thyroid or other chronic diseases, nor were they taking iodine-containing supplements at enrollment. In the first trimester, we obtained clinical information and determined thyroid function and the urinary iodine concentration (UIC) of the participants. Thyroid function and UIC were reassessed in the third trimester. Iodine status was determined by the median of UIC obtained from six urine spot samples by the inductively coupled plasma mass spectrometry method. Pregnancy and neonatal outcomes and delivery information were obtained from medical records. Results: The median UIC in the whole population was 219.7 μg/L. The prevalence of UIC <150 μg/L was 17.2%, and 38.7% had UIC ≥250 μg/L. Gestational diabetes (GDM) was higher in the group with UIC 250-499 μg/L (n = 77) compared with the group with UIC 150-249 μg/L (n = 94) (20.3% vs. 9.7%, p < 0.05). Ultimately, UIC ≥250 μg/L was an independent risk factors for GDM (relative risk [RR] = 2.9 [confidence interval, CI = 1.1-7.46], p = 0.027) and hypertensive disorders of pregnancy (HDP) (RR = 4.6 [CI = 1.1-18.0], p = 0.029). Among 196 live-born newborns, lower birth length was observed in infants whose mothers had UIC <150μg/L (n = 37) in the first trimester compared with those with UIC 150-249 μg/L (n = 86) (median interquartile range: 48.0 [2.2] vs. 49.0 [4.0] cm, p = 0.01). Maternal UIC <150 μg/L was negatively associated with birth length of newborns (Exp (B) = 0.33 [CI = 0.1-0.9], p = 0.03). Conclusions: In a population whose median iodine intake is sufficient, extensive individual variation occurs. Such abnormalities are associated with increased GDM and HDP when UIC is ≥250 μg/L, and lower infant birth length when UIC is <150 μg/L.

Inductively coupled plasma with mass-spectrometry method development and validation for gadolinium in gadolinium-based contrast agents of pharmaceutical formulations

Gadolinium-based contrast agent interacts with the human body temporarily and improves the pictures of inside of the body produced by magnetic resonance imaging, computed tomography, X-rays and ultrasound and it also helps to distinguish the normal from abnormal conditions. In this study, the authors developed a simple, rapid, reliable and robust inductively coupled plasma mass-spectrometry method for estimation of gadolinium in gadolinium-based contrast agents to check the drug quality and ensure the patient safety. The samples were digested at 160°C using the microwave digestion system and the gadolinium was extracted in 0.4% (w/w) nitric acid. Interference of deposited gadolinium on sample cone and skimmer cone were investigated and evaluated. The developed method was validated as per ICH Q2 (R1) guideline and USP&lt;730&gt;. The precision was evaluated with six independent assays of gadolinium in each gadolinium-based contrast agent. The test method was found linear (r2 &gt; 0.999) with five different levels covered from 25~200%, and accurate, mean recoveries were 92.5~107.5% at three different levels covered from 50~150%. The robustness was performed by changing the nitric acid concentration (0.4±0.04%, w/w) in diluent system. This method is suitable to quantitatively determine the amount of gadolinium in gadolinium-based contrast agent of drug products in presence of excipients used in formulation and also in drug substance.

Speciation Analysis of Chromium in Chromium-Enriched Yeast by Ion Chromatography-Inductively Coupled Plasma Mass Spectrometry.

Chromium-enriched yeast (CrY) is a popular Cr dietary supplement, but suitable speciation analysis of highly toxic Cr(VI) in CrY is not available. Ion chromatography-inductively coupled plasma mass spectrometry method was firstly developed and validated for the quantification of Cr(III) and Cr(VI). Ultrasound-assisted weakly alkaline EDTA solution combined with boiling was used to extract two Cr species in CrY. Two species were separated on two successive anion-exchange columns using a mobile phase of 0.6mmol/L EDTA and 76mmol/L NH4NO3 solution. The method was sensitive, accurate (92.4-100.9%), and precise (0.8-3.1%). Species of Cr(VI) were not found in CrY.

A metabolomic study on the association of exposure to heavy metals in the first trimester with primary tooth eruption

BackgroundThe influence of prenatal heavy metals exposure on primary tooth eruption in humans is rarely reported. AimBased on the cohort study design, we investigated the association of exposure to 12 heavy metals in the first trimester with primary tooth eruption, and the maternal metabolisms in the first trimester which might be related to the above relationship. MethodsMaternal urine samples were collected in their first trimester, and 12 metals (Ti, V, Fe, Co, Cu, As, Se, Cd, Sn, Hg, Tl, U) were measured using the inductively coupled plasma mass spectrometry method. The maternal metabolome in the first trimester was analyzed by ultrahigh performance liquid chromatography coupled mass spectrometry based metabolomics using urine samples. The infant's first tooth eruption time and number of teeth at age one were recorded by oral examination and questionnaire. ResultsNo significant associations were observed between heavy metals exposure in the first trimester and primary tooth eruption, except for Co. The level of Co was positively associated with time of infant's first tooth eruption, and was negatively associated with the number of teeth at age one. Based on metabolomic profiling, glycine was revealed as the key mediating metabolite, which showed negative correlation with Co and opposite effect of Co in the primary tooth eruption. ConclusionsPrenatal Co exposure in the first trimester might delay the primary tooth eruption in children through the decreased glycine-disrupted dentin formation, providing the first evidence and novel insights into the control of prenatal heavy metals exposure for ensuring normal (timely) primary tooth eruption.

Rapid inductively coupled plasma mass spectrometry method to determine iodine in amniotic fluid, breast milk and cerebrospinal fluid

BackgroundGiven that both insufficient and excess maternal iodine have adverse consequences such as poor cognitive performance, delayed physical development and increased fetal and infant mortality, the determination of maternal iodine status is very important. In this study, we established and verified a method involving inductively coupled plasma-mass spectrometry (ICP-MS) technology for the rapid determination of the amniotic fluid iodine concentration (AFIC), breast milk iodine concentration (BMIC) and cerebrospinal fluid (CSF) iodine concentration (CSFIC). MethodAmniotic fluid, breast milk and CSF were collected from residual samples at Peking Union Medical College Hospital (PUMCH). The linearity, detection limit, precision, recovery, carryover and matrix effect of the testing method using ICP-MS technology were thoroughly evaluated according to the EP-10-A2 evaluation protocol approved by the Clinical and Laboratory Standards Institute (CLSI) guidelines. Furthermore, we evaluated the AFIC, BMIC and CSFIC distributions among clinical patients from PUMCH. ResultsThe correlation coefficient (r) was higher than 0.99 (0.995–1.000). The limit of detection (LOD) was 0.233 µg/L, and the limit of quantification (LOQ) was 0.778 µg/L. For amniotic fluid, breast milk and CSF, the assay repeatabilities were 1.5%–1.8%, 1.9%–4.0% and 1.8%–4.0%, respectively, and the within-laboratory coefficient of variations (CV%) over five days were 3.3%–9.2%, 7.2%–8.0% and 3.2%–7.8%, respectively. The recovery rates ranged from 97.7% to 109.8%. Moreover, the median concentrations of iodine in the amniotic fluid, breast milk and CSF of the patients from PUMCH were 176.3 µg/L, 136.0 µg/L, and 81.8 µg/L, respectively. ConclusionA rapid, stable and accurate method that incorporates ICP-MS technology for the determination of iodine concentration was established for amniotic fluid, breast milk and CSF in this study.

Пространственно-временные изменения вещественного состава донных отложений и речных вод Туганского россыпного узла (Томская область)

The changes in the chemical and mineral composition of bottom sediments and waters of the Omutnaya River (the element of the Omutnaya–Kirghizka–Tom–Ob river system) during the main phases of the water regime in 2018–2019 within the planned Tugan placer deposit (ore minerals—ilmenite and zircon) have been studied. Geochemical parameters were estimated using an inductively coupled plasma mass spectrometry method. It was obtained that the spatiotemporal changes in the gross contents of chemical elements are generally interrelated with their migration forms. General increase in the concentrations of substances in suspended form is predominant and noted in spring floods, with dissolved—in the winter low-water period. Changes in the chemical composition of bottom sediments (fraction up to 1 mm) during the year and from the source to the mouth of the river due to the influence of local geological and hydrological factors are weaker than the corresponding changes in the chemical composition of river waters. Based on the studies, it was shown that the maximum concentrations of ore elements within the halos of placer deposits are most likely under conditions of a relatively stable (geologically) decrease in the intensity of water exchange.