Accurate determination of ultra-trace levels of Ti in blood serum using ICP-MS/MS

Trace Element Exposure during Pregnancy Has a Persistent Influence on Perinatal Gut Microbiota in Mother-Infant Dyads

Trace elements have been recognized as the modifiers of the gut microbiota. However, population-based evidence about their effects on maternal gut microbiota dynamics, as well as the intergenerational impacts on neonatal gut microbiota, has been lacking. We examined the longitudinal microbiota data from mother-infant dyads and demonstrated that maternal trace element exposure played a pivotal role in shaping the composition and similarity of the mother-infant gut microbiota. Specifically, serum levels of cobalt (Co), molybdenum (Mo), and rubidium (Rb) were identified to cause further fluctuation in the shift of the maternal gut microbiota. Antibiotic usage shortly before or on the delivery day, as well as maternal zinc (Zn) exposure, affected the gut microbiota similarity within mother-infant dyads. Rb demonstrated an intergenerational effect on meconium Bifidobacterium abundance by altering its abundance in the maternal gut. Notably, this effect was strengthened in the vaginal delivery group without antibiotic usage, while it was attenuated in the c-section delivery group. Our results suggest that maternal trace element exposure has a persistent influence on perinatal gut microbiota, which offers novel insights into promoting mother and infant health.

The importance of ion kinetic energy for interference removal in ICP-MS/MS

The effect of ion kinetic energy on gas phase ion reactivity with ICP-MS/MS was investigated in order to explore tuning strategies for interference removal. The collision/reaction gases CO2, N2O and O2 were used to observe the ion product distribution for 48 elements using an Agilent tandem ICP-MS (ICP-MS/MS) as a function of reaction gas flow rate (pressure) and ion kinetic energy. The kinetic energy of the incident ion was varied by adjusting the octopole bias (Voct). The three gases all form oxides (MO+) as the primary product with differing reaction enthalpies that result in distinct differences in the ion energies required for reaction with product ion distributions that vary with Voct. Consequently, by varying the ion kinetic energy (i.e., Voct), differences in interference reactivity can be used to achieve maximum separation. Three practical application examples were reported to demonstrate how the ion kinetic energy can be varied to achieve the ideal ion product distribution for interference resolution: CO2 for the removal of 238U in Pu analyses, CO2 for the removal of 40Ar16O vs. 56Fe, and O2 for the removal of Sm in Eu analyses, analogous to Pu/Am. The results demonstrate how the starting ion energy defined by Voct is an important factor to fully leverage the utility of any given reaction gas to remove interferences in the mass spectrum using ICP-MS/MS.

Concentrations of Cobalt, Chromium and Titanium and Immunological Changes after Primary Total Knee Arthroplasty-A Cohort Study with an 18-Year Follow-Up

Background: Total knee arthroplasty (TKA) generates elevated metal ion concentrations, but long-term changes in the concentrations of cobalt (Co), chromium (Cr) and titanium (Ti) after primary TKA and potential subsequent immune system activation-not limited to the joint but systemically-are not known. Patients and Methods: We conducted a cohort study on 26 patients with TKA (19 women; 16 with metal-backed and 10 with all-polyethylene tibial components) 18.3 years (min. 16.7, max. 20.5) after index TKA. A total of 69% of patients additionally underwent subsequent arthroplasty of the contralateral knee or either hip after the index surgery. Blood samples were analysed by inductively coupled plasma-mass spectrometry, and leukocytes were characterised by flow cytometry. Patients were clinically assessed using the Knee Society score and by plain radiography of the knee. Results: The median metal ion concentrations were 0.7 (0.1-13.0) µg/L for Co, 0.9 (0.4-5.0) µg/L for Cr, and 1.0 (0.2-13.0) µg/L for Ti. There was no relevant difference in systemic metal ion concentrations between patients exposed to single and multiple arthroplasties. The absolute count and proportion of CD3+CD4+CD8+ T cells was inversely correlated with both Co (rho -0.55, p = 0.003) and Cr concentrations (rho -0.59, p = 0.001). Conclusions: Between the first and second decades after primary TKA, in most patients, the concentrations of Co, Cr and Ti in blood samples were below the thresholds that are considered alarming. The negative correlation of Co and Cr concentrations with a subset of lymphocytes that commonly increases during immune activation is reassuring. This represents a worst-case scenario, underscoring that the investigated metal ions remain within reasonable ranges, even after additional hardware exposure.

An ICP-MS-Based Analytical Strategy for Assessing Compliance with the Ban of E 171 as a Food Additive on the EU Market

A method was developed for the determination of total titanium in food and food supplements by inductively coupled plasma mass spectrometry (ICP-MS) after microwave-assisted acid digestion of samples. Five food supplements, including one certified reference material, and 15 food products were used for method development. Key factors affecting the analytical results, such as the composition of the acid mixture for sample digestion and the bias from spectral interferences on the different titanium isotopes, were investigated. Resolution of interferences was achieved by ICP-MS/MS with ammonia adduct formation and viable conditions for control laboratories equipped with standard quadrupole instruments were identified. The method was successfully validated and enables rapid screening of samples subject to confirmatory analysis for the presence of TiO2 particles. For the latter, single-particle ICP-MS (spICP-MS) analysis after chemical extraction of the particles was used. The two methods establish a viable analytical strategy for assessing the absence of titania particles in food products on the EU market following the E 171 ban as a food additive.

Whole Blood Titanium Concentration after Limb Salvage Surgery with Three-Dimensional-Printed Ti6Al4V Implants

Background

Three-dimensional (3D)-printed customized implants can be fabricated and utilized for all bones with massive bone defects. The main safety issues with 3D-printed implants made of Ti6Al4V alloy are related to the release of metal debris and residual powder. In this study, we investigated the perioperative titanium concentrations in whole blood and peri-implant fluid samples of patients who underwent limb salvage surgery with a 3D-printed Ti6Al4V implant.

Methods

Nineteen patients who underwent limb salvage surgery with 3D-printed Ti6Al4V implants were divided into two groups: the serial samples group and the follow-up group. To observe metal distribution and clearance in the body, serial samples of blood and peri-implant fluid from the surgical drain were prospectively collected for five patients in the serial samples group. For the remaining 14 patients who were followed up for more than a year, blood samples were collected only once.

Results

In the serial samples group, the mean baseline titanium concentration was 0.78 µg/L (range, 0.1-2.2 µg/L): 3 patients showed peak concentration before the third postoperative month, while 2 patients still showed an increasing pattern at this point. Total titanium mass in the surgical drain showed a wash-out phenomenon in a week, with a significant uniform decrease (p = 0.04). In 14 patients in the follow-up group, the mean titanium concentration in the whole blood was 10.8 µg/L (range, 0.3-36.6 µg/L). For the 14 patients with a long-term follow-up, the aluminum and vanadium concentrations were all negligible.

Conclusions

Whole blood titanium concentrations were higher after surgery using 3D-printed implants than after that using conventional orthopedic implants, but markedly lower than in patients with implant failure. None of the patients developed serious clinical adverse effects during follow-up.

Analysis of Ti- and Pb-based particles in the aqueous environment of Melbourne (Australia) via single particle ICP-MS

The analysis of natural and anthropogenic nanomaterials (NMs) in the environment is challenging and requires methods capable to identify and characterise structures on the nanoscale regarding particle number concentrations (PNCs), elemental composition, size, and mass distributions. In this study, we employed single particle inductively coupled plasma-mass spectrometry (SP ICP-MS) to investigate the occurrence of NMs in the Melbourne area (Australia) across 63 locations. Poisson statistics were used to discriminate between signals from nanoparticulate matter and ionic background. TiO2-based NMs were frequently detected and corresponding NM signals were calibated with an automated data processing platform. Additionally, a method utilising a larger mass bandpass was developed to screen for particulate high-mass elements. This procedure identified Pb-based NMs in various samples. The effects of different environmental matrices consisting of fresh, brackish, or seawater were mitigated with an aerosol dilution method reducing the introduction of salt into the plasma and avoiding signal drift. Signals from TiO2- and Pb-based NMs were counted, integrated, and subsequently calibrated to determine PNCs as well as mass and size distributions. PNCs, mean sizes, particulate masses, and ionic background levels were compared across different locations and environments.

Evaluation of trace-element contamination from serum collection tubes used by the California Biobank Program

BACKGROUND

Serum samples archived by the California Biobank Program (CBP) can be a valuable resource to researchers with multiple benefits: affordability, relatively large sample sizes, and racial and geographical representativeness. However, there has been little attention given to the reliability of CBP samples for trace-element analysis. The objectives of this study are to estimate the contamination levels from the serum separation tubes (SST, BD 367983) utilized by the CBP for 13 trace elements (Cr, Mn, Co, As, Se, Sr, Mo, Cd, Sb, Hg, Tl, Pb and U) and to evaluate the feasibility of the use of CBP serum samples for biomonitoring trace elements in human body.

METHODS

Serum separation tubes were tested using deionized (DI) water and whole blood and compared with two alternative sampling devices, plasma separation tubes (PST, BD 365047) and acid-cleaned blood tubes (ABT, BD 367856).

RESULTS AND CONCLUSIONS

The leaching tests for SSTs with DI water demonstrated that detectable levels of Cr, Mn, Co, Sr, Sb, Pb and U were measured, while Sb was elevated. Tests of PSTs also revealed contamination of Mn, Co, Sr and Sb, with Co and Sr being much higher than those found from SSTs. As a more direct approach to estimate trace element contamination, a 45-day time series was conducted using human blood. The differences in elemental concentrations leached into serum/plasma was not considerable between the three types of sampling tubes for Cr, As, Se, Mo, Cd, Hg and Tl. However, SSTs had far greater concentrations than the ABTs for Mn, Co, Sr, Sb and U. For Co and Sr, the PSTs had higher concentrations throughout the experiment than both ABTs and SSTs. Pb showed lower concentrations from the PSTs than the other tubes; we speculate this may be due to re-suspension of settled cellular materials that are elevated in Pb, or re-dissolution of Pb from these materials. Trace-element measurements from 200 samples archived by the CBP using SSTs suggest that SST contamination was negligible for Se and Mo. For Mn, As, Sr, Cd and Hg, based on our leaching results, only a fraction of these samples had considerably high concentrations (e.g., > 10×) compared to the contamination from the SST. For Cr, Co, Sb, Tl, Pb and U, analyte levels were too low in most samples compared to the contamination from the SSTs. Our study also demonstrated that the PSTs could be a "cleaner" alternative to SSTs for analytes such as Cr, As, Cd, Hg, Tl, Pb and U.

Latest Trends in Surface Modification for Dental Implantology: Innovative Developments and Analytical Applications

An increase in the world population and its life expectancy, as well as the ongoing concern about our physical appearance, have elevated the relevance of dental implantology in recent decades. Engineering strategies to improve the survival rate of dental implants have been widely investigated, focusing on implant material composition, geometry (usually guided to reduce stiffness), and interface surrounding tissues. Although efforts to develop different implant surface modifications are being applied in commercial dental prostheses today, the inclusion of surface coatings has gained special interest, as they can be tailored to efficiently enhance osseointegration, as well as to reduce bacterial-related infection, minimizing peri-implantitis appearance and its associated risks. The use of biomaterials to replace teeth has highlighted the need for the development of reliable analytical methods to assess the therapeutic benefits of implants. This literature review considers the state-of-the-art strategies for surface modification or coating and analytical methodologies for increasing the survival rate for teeth restoration.

Cytotoxicity and Ion Release of Functionally Graded Al₂O₃- Ti Orthopedic Biomaterial

The aim of this study was to evaluate the biocompatibility of Al2O3-Ti functionally graded material (FGM) successfully fabricated by Spark Plasma Sintering (SPS) technology, and to compare with pure Ti and alumina. Pre-osteoblast MC3T3-E1 cells were used to examine cell viability, proliferation and differentiation using lactate dehydrogenase (LDH) cytotoxicity detection kit, MTT assay and Alkaline Phosphatase (ALP) colorimetric test at different time points. Furthermore, ion release from the materials into the culture medium was assessed. The results showed cell viability over 80% for FGM and alumina which dismissed any cytotoxicity risk due to materials or manufacturing. The results of MTT tests identified superiority of FGM than Ti and alumina, particularly in late proliferation. Nevertheless, in cell differentiation, all materials performed similarly with no statistical differences. Furthermore, it was indicated that Ti had no ion release, while alumina had small amount of Al ion dissolution. FGM, however, had more ions detachment, particularly Al ions.

Multi-elemental determination of metals, metalloids and rare earth element concentrations in whole blood from the Canadian Health Measures Survey, 2009-2011

BACKGROUND

As part of Government of Canada's Chemical Management Plan, substances containing aluminum (Al), bismuth (Bi), cerium (Ce), chromium (Cr), germanium (Ge), lanthanum (La), lithium (Li), neodymium (Nd), praseodymium (Pr), tellurium (Te), titanium (Ti) and yttrium (Y) were identified as priorities for risk assessment. Generating exposure estimates from all routes of exposure from multiple sources using a traditional approach for these elements can be challenging. The use of human biomonitoring (HBM) data would allow for direct and more precise assessment of the internal concentrations from all routes and all sources of exposure. There are no Canadian or North American population-level whole blood HBM data for the elements listed above. Therefore, this is the first biomonitoring project carried out to determine the concentrations of these elements from a nationally representative sample of Canadians.

OBJECTIVES

The objective of this study was to generate whole blood concentrations for Al, Bi, Ce, Cr, Ge, La, Li. Nd, Pr, Te, Ti and Y in the Canadian population using biobank samples from the Canadian Health Measures Survey (CHMS) cycle 2 (2009-2011) for use in characterizing exposure in screening assessments and for establishing baseline concentrations to determine how exposures are changing over time.

METHODS

The sample analysis was conducted by ICP-MS. A rigorous quality control and quality assurance process was implemented in order to generate data with high accuracy and precision while measuring low concentrations and minimizing possible inadvertent contamination.

RESULTS

Of the elements analysed, the whole blood concentrations (μg/L) of Al, Ce, Cr, Ge, La, Nd, Pr, Te, Ti and Y in the Canadian population aged 3-79 years were below their respective method reporting limit (MRL). Two elements, Bi and Li were detected in 5 % and 66 % of the Canadian population. The median Li concentration was 0.47 μg/L.

CONCLUSION

The results of this study provide information on concentrations of these elements in the Canadian population which can be utilized to characterize exposure in screening assessments and there by the potential for harm to human health. In addition, this study provides baseline HBM data which can be used as a comparative HBM dataset for other populations with similar exposure patterns.

Contribution of trace element exposure to gestational diabetes mellitus through disturbing the gut microbiome

BACKGROUND

A healthy gut microbiome is critical for glucose metabolism during pregnancy. In vivo studies indicate that trace element affects the composition and function of the gut microbiome and potentially leads to metabolic disorders but their relationships are largely unknown. We aimed to investigate whether the gut microbiome plays a role in the relationship between trace element exposure and gestational diabetes mellitus (GDM).

METHODS

In a prospective cohort study, serum levels of 22 trace elements and the fecal gut microbiome composition were assessed in 837 pregnant women in the second trimester between 22 and 24 weeks of pregnancy prior to GDM diagnosis. Regression and mediation analysis were used to explore the link between element exposure, the gut microbiome, and GDM.

RESULTS

128 pregnant women (15.3%) were diagnosed with GDM. No individual trace elements were found significantly associated with GDM. In contrast, the composition of the gut microbiome was dramatically altered in women later diagnosed with GDM and characterized by lower alpha diversity and lower abundance of co-abundance groups (CAGs) composed of genera belonging to Ruminococcaceae, Coriobacteriales, and Lachnospiraceae. Rubidium (Rb) was positively associated with alpha diversity indices while mercury (Hg) and vanadium (V) showed negative associations. Elements including rubidium (Rb), thallium (Tl), arsenic (As), and antimony (Sb) were significantly correlated with GDM-related CAGs and mediation analysis revealed that Rb and Sb were inversely related to GDM risk by altering abundance levels of CAGs enriched for Lachnospiraceae, Coriobacteriales, and Ruminococcaceae.

CONCLUSION

Our study indicates that trace element exposure is associated with specific gut microbiome features that may contribute to GDM development, which could provide a new avenue for intervening in environmental exposure-related GDM.

Elemental Testing Using Inductively Coupled Plasma Mass Spectrometry in Clinical Laboratories

OBJECTIVES

This review aims to describe the principles underlying different types of inductively coupled plasma mass spectrometry (ICP-MS), and major technical advancements that reduce spectral interferences, as well as their suitability and wide applications in clinical laboratories.

METHODS

A literature survey was performed to review the technical aspects of ICP-MS, ICP-MS/MS, high-resolution ICP-MS, and their applications in disease diagnosis and monitoring.

RESULTS

Compared to the atomic absorption spectrometry and ICP-optical emission spectrometry, ICP-MS has advantages including improved precision, sensitivity and accuracy, wide linear dynamic range, multielement measurement capability, and ability to perform isotopic analysis. Technical advancements, such as collision/reaction cells, triple quadrupole ICP-MS, and sector-field ICP-MS, have been introduced to improve resolving power and reduce interferences. Cases are discussed that highlight the clinical applications of ICP-MS including determination of toxic elements, quantification of nutritional elements, monitoring elemental deficiency in metabolic disease, and multielement analysis.

CONCLUSIONS

This review provides insight on the strategies of elemental analysis in clinical laboratories and demonstrates current and emerging clinical applications of ICP-MS.

Determination of ultra-trace levels of titanium in human serum using inductively coupled plasma tandem mass spectrometry based on O2/H2 reaction gas

This study proposes a new strategy to determine ultra-trace Ti in human serum using inductively coupled plasma tandem mass spectrometry (ICP-MS/MS). The human serum samples were diluted with 1% (v/v) HNO₃, followed by the determination of ultra-trace Ti using ICP-MS/MS. In the MS/MS mode, a small amount of H₂ was mixed with O₂ (the reaction gas) in a collision reaction cell (CRC) to form an O₂/H₂ reaction mixture, and then, the conversion of Ti⁺ to TiO⁺ was determined by the O₂ mass shift method. High concentrations of Ca, S, and P in human serum were ionized in plasma, and the formed Ca⁺, SO⁺, and PO ⁺ reacted with O₂ in CRC to form CaO⁺, SO₂⁺, and PO₂⁺ to interfere with the determination of TiO⁺. We employed the mass shift reaction of H₂ and oxide ions to eliminate this interference. This method was evaluated using the human serum sample spike recovery experiment and comparative analysis by sector field (SF)-ICP-MS. The results showed that using reaction gas mixture O₂/H₂ reduced the background equivalent concentration (BEC) of Ti and improved sensitivity. The values determined by this method were consistent with the SF-ICP-MS values, which confirmed its accuracy and reliability. The limit of detection (LOD) of Ti was 0.78-7.20 ng L^-1, the recovery was 96.0%-104%, and the relative standard deviation (RSD) was 2.0%-4.2%. This method has solved the problem that the determination of ultra-trace Ti in human serum cannot be accurately determined using O₂ reaction mode. It realizes the interference-free and highly sensitive determination of the ultra-trace Ti in samples with high levels of Ca, S, and P and provides a new technique for high-throughput and accurate determination of ultra-trace Ti in human serum.

Metallomics-based platforms for comparing the human blood serum profiles between bipolar disorder and schizophrenia patients

RATIONALE

An evaluation of bipolar disorder (BD) and schizophrenia (SCZ) was carried out, from a metallomics point of view, using native conditions, attempting to preserve the interaction between metals and biomolecules.

METHOD

For this task, blood serum samples from healthy individuals and patients were compared. In addition, the profiles of metal ions and metalloids involved in the pathologies were quantified, and a comparison was carried out of the protein profile in serum samples of healthy individuals and diseased patients.

RESULTS

After optimization and accuracy evaluation of the method, different concentrations of Li, Mg, Mn and Zn were observed in the samples of BD patients and high levels of copper for SCZ patients, indicating an imbalance in the homeostasis of important micronutrients. The treatment, especially with lithium, may be related to competition between metallic ions. BD-related metallobiomolecules were detected, preserving the binding between metal ions and biomolecules, with four fractions detected in the ultraviolet range (280 nm). Four fractions were collected by high-performance liquid chromatography/inductively coupled plasma mass spectrometry (HPLC/ICP-MS) and the proteins were identified by liquid chromatography/tandem mass spectrometry (LC/MS/MS). The Ig lambda chain V-IV region Hil, immunoglobulin heavy constant gama 1 (IGHG1) and beta-2-glycoprotein 1 (or ApoH) was identified in SCZ samples, suggesting its relationship with mood disorders. Surprisingly, Protein IGKV2D-28 was identified only in BD samples, opening up new possibilities for studies regarding the role of this protein in BD.

CONCLUSIONS

This approach brings new perspectives to the comprehension of mood disorders, highlighting the importance of metallomics science in disease development. This strategy showed an innovative potential for evaluating mood disorders at the proteomic level, making it possible to identify proteins related to mood disorders and BD.

Challenges in the Measurement and Interpretation of Serum Titanium Concentrations

The measurement of circulating metal ion levels in total hip arthroplasty patients continues to be an area of clinical interest. National regulatory agencies have recommended measurement of circulating cobalt and chromium concentrations in metal-on-metal bearing symptomatic total hip arthroplasty patients. However, the clinical utility of serum titanium (Ti) measurements is less understood due to wide variations in reported values and methodology. Fine-scale instrumentation for detecting in situ Ti levels continues to improve and has transitioned from graphite furnace atomic absorption spectroscopy to inductively coupled plasma optical emission spectrometry or inductively coupled plasma mass spectrometry. Additionally, analytical interferences, variable sample types, and non-standardized sample collection methods complicate Ti measurement and underlie the wide variation in reported levels. Normal reference ranges and pathologic ranges for Ti levels remain to be established quantitatively. However, before these ranges can be recognized and implemented, methodological standardization is necessary. This paper aims to provide background and recommendations regarding the complexities of measurement and interpretation of circulating Ti levels in total hip arthroplasty patients.

Microelement composition of serum in Dolgans, indigenous inhabitants of the Russian Arctic, in the conditions of industrial development of territories

The geochemical conditions of landscapes are the content in the environment of certain chemical elements and their compounds, the lack or excess of which causes deviations in the state of human health. This problem has arisen in connection with the extraction of alluvial diamonds and the forthcoming development of the Tomtor deposit of rare-earth metals in the territories where the indigenous peoples of the North live. The study included 107 indigenous people of the North, belonging to the ethnic group of Dolgans living in the village of Yuryung-Khaya, Anabar district, Yakutia of Russia. The method of mass spectrometry was used to study the content of 13 trace elements in blood serum (P, Sc, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Rb, Sr, Cs, Pb). The study revealed an increase in the content of the macroelement phosphorus (148 mg/L) and trace elements of chromium (277 μg/L), manganese (133 μg/L), iron (5219 μg/L), nickel (57 μg/L) in serum of Dolgans, which may affect the development of diseases of the cardiovascular system and other diseases among indigenous inhabitants of the Arctic under conditions of industrial development of territories.

Gastrointestinal Absorption and Toxicity of Nanoparticles and Microparticles: Myth, Reality and Pitfalls explored through Titanium Dioxide

Daily oral exposure to vast numbers (>1013/adult/day) of micron or nano-sized persistent particles has become the norm for many populations. Significant airborne particle exposure is deleterious, so what about ingestion? Titanium dioxide in food grade form (fgTiO2) , which is an additive to some foods, capsules, tablets and toothpaste, may provide clues. Certainly, exposed human populations accumulate these particles in specialised intestinal cells at the base of large lymphoid follicles (Peyer's patches) and it's likely that a degree of absorption goes beyond this- i.e. lymphatics to blood circulation to tissues. We critically review the evidence and pathways. Regarding potential adverse effects, our primary message, for today's state-of-art, is that in vivo models have not been good enough and at times woeful. We provide a 'caveats list' to improve approaches and experimentation and illustrate why studies on biomarkers of particle uptake, and lower gut/mesenteric lymph nodes as targets, should be prioritized.

Inductively Coupled Plasma Mass Spectrometry: Introduction to Analytical Aspects

Inductively coupled plasma mass spectrometry (ICP-MS) is an analytical technique that can be used to measure elements at trace levels in biological fluids. Although older techniques such as atomic absorption and atomic emission are still in use by some laboratories, there has been a slow shift toward ICP-MS, particularly in the last decade. As this shift is likely to continue, clinical scientists should be aware of the analytical aspects of ICP-MS, as well as the potential for both spectroscopic and non-spectroscopic interference, and strategies that can be employed to eliminate or mitigate these issues.

Blood titanium level as a biomarker of orthopaedic implant wear

BACKGROUND

Joint replacement implants are usually manufactured from cobalt-chromium or titanium alloys. After the device is implanted, wear and corrosion generate metal particles and ions, which are released into local tissue and blood. The metal debris can cause a range of adverse local and systemic effects in patients.

RESEARCH PROBLEM

In the case of cobalt and chromium, a blood level exceeding 7 μg L^-1 indicates potential for local toxicity, and a failing implant. It has been repeatedly suggested in the literature that measurement of titanium could also be used to assess implant function. Despite an increasing interest in this biomarker, and growing use of titanium in orthopaedics, it is unclear what blood concentrations should raise concerns. This is partly due to the technical challenges involved in the measurement of titanium in biological samples.

AIM

This Review summarises blood/serum titanium levels associated with well-functioning and malfunctioning prostheses, so that the prospects of using titanium measurements to gain insights into implant performance can be evaluated.

CONCLUSION

Due to inter-laboratory analytical differences, reliable conclusions regarding "normal" and "abnormal" titanium levels in patients with orthopaedic implants are difficult to draw. Diagnosis of symptomatic patients should be based on radiographic evidence combined with blood/serum metal levels.

Theoretical insights into the competitive metal bioaffinity of lactoferrin as a metal ion carrier: a DFT study

Metal–protein complexes, specifically lactoferrin (Lf), an iron-binding glycoprotein found naturally in milk and several other body fluids play a pivotal role in all living organisms.

Differential diagnosis of multielements in cancerous and non-cancerous esophageal tissues

It is known that variations in the concentrations of certain elements in humans may be an indication of cancers. In this work, a method for the quantitative analysis of 22 elements in non-tumor and esophageal squamous cell carcinoma (ESCC) tissues from the same individual is reported. Based on the optimized platform combined with multivariate analysis, diagnostic models of ESCC were established using principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA), showing excellent classification of cancerous and non-cancerous group by metallomic profiling. Elemental concentrations of 10 elements (Mn, Se, Cu, Ti, Mg, Fe, Co, Zn, Sr, Ca) showed significant difference (p < 0.001) in tumor and non-tumor tissues, in which Mn, Se, Cu and Ti are the top 4 elements of statistical significance and a shift towards higher concentration levels has also been observed in the tumor samples. These results confirm the considerable potential of elemental studies for biomedical purposes. To our knowledge, previous studies on elemental concentration in esophageal cancer were performed in serum or plasma levels; and this is the first study to evaluate the association of tissue elemental concentrations with ESCC.

Distribution and predictors of 20 toxic and essential metals in the umbilical cord blood of Chinese newborns

Early-life exposure to heavy metals and/or trace metal imbalances can have negative developmental effects. Here we sought to characterize exposure profiles for 20 heavy metals and trace elements in umbilical cord blood plasma and identify demographic predictors of exposure. Twenty metals were measured in cord plasma from 357 Chinese infants using ICP-MS. Relationships between demographic variables and metals were analyzed using generalized linear models and logistic regression. Ten metals (antimony [Sb], cobalt [Co], cesium [Cs], copper [Cu], lead [Pb], molybdenum [Mo], rubidium [Rb], selenium [Se], strontium [Sr], titanium [Ti], zinc [Zn]) were detected in all samples. Season of birth was the strongest predictor of metals in cord blood across analyses. Infants born in the spring had 0.1-0.2 μg L-1 higher logAs and logCo in their cord blood (β [95%CI] = 0.22 [0.01,0.42], p = 0.04; 0.11 [0.01,0.22], p = 0.04), while infants born in the summer had higher Sb, logB, logHg, and logZn (β [95%CI] = 0.74 [0.24,1.24], p = 0.004; 0.11 [0.00,0.21], p = 0.04; 0.29 [0.08,0.49], p = 0.007; 0.18 [0.06,0.31], p = 0.005), compared to those born in fall/winter. Prenatal heavy metal exposure and/or trace metal deficiencies are global concerns because of increasing awareness of downstream developmental effects.

A Randomized Seven-Year Study on Performance of the Stemmed Metal M2a-Magnum and Ceramic C2a-Taper, and the Resurfacing ReCap Hip Implants

BACKGROUND

The large-diameter metal-on-metal hip prostheses were expected to have low wear and reduced dislocation rate compared to the traditional metal-on-polyethylene implants. We compare 2 such prostheses, the ReCap resurfacing implant and the M2a-Magnum stemmed implant, with the C2a ceramic-on-ceramic stemmed implant as to clinical performance, serum concentrations of prosthesis metals, and the durability of the implants in a randomized, controlled clinical trial at 7 years of follow-up.

METHODS

All included patients had osteoarthritis. Preoperatively, the size of the implants was estimated from a magnetic resonance imaging (MRI) scan. Follow-up data included serum cobalt and chromium concentrations, Oxford and Harris Hip Scores, leg press and abduction force, 6-minute walk distance, WOMAC and SF-36 self-assessment scores, and from the 7th postoperative year also ultrasonography (US) examination of the soft tissue adjacent to the implant as well as MRI with metal artifact reduction sequence (MARS-MRI) when indicated.

RESULTS

One hundred fifty-two hips in 146 patients were included. The serum cobalt and chromium concentrations were significantly higher for the 2 metal-on-metal prostheses than for the ceramic-on-ceramic, with the M2a-Magnum as the highest. No significant difference was found between the groups concerning physical performance measurements and scores as well as dislocations and prosthesis survival. Five revisions were done and concerned all groups, for reasons of pain, high serum cobalt and chromium concentrations, cystic fluid collection around the joint, and infection. Metal concentrations, US, and MARS-MRI contributed to the decision making regarding prosthesis revision.

CONCLUSION

Metal concentrations were significantly higher for the metal-on-metal prostheses than for the ceramic-on-ceramic. The clinical performance was good in all 3 prosthesis groups. Metal concentrations, US, and MARS-MRI findings were of use to identify hips needing revision. ID Number in ClinicalTrials.gov PRS: NCT00284674.

Analysis of soluble or titanium dioxide derived titanium levels in human whole blood: consensus from an inter-laboratory comparison

Exposure to titanium (Ti),viathe ingestion of pigment grade Ti dioxide (TiO₂), is commonplace for westernised populations.

Release of titanium after insertion of dental implants with different surface characteristics - an ex vivo animal study

In the present study, amount of titanium (Ti) released into the surrounding bone during placement of implants with different surface structure was investigated. Quantification of Ti released during insertion from three different implants was performed in this ex vivo study. Jaw bone from pigs was used as model for installation of the implants and Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) was used for analysis of the released Ti. Implant surface were examined with scanning electron microscopy (SEM), before and after the placement into the bone. Ti was abraded to the surrounding bone upon insertion of a dental implant and the surface roughness of the implant increased the amount of Ti found. Diameter and total area of the implant were of less importance for the Ti released to the bone. No visible damages to the implant surfaces could be identified in SEM after placement.

Measurement of titanium in hip-replacement patients by inductively coupled plasma optical emission spectroscopy

Background

Patients with metal-on-metal hip replacements require testing for cobalt and chromium. There may also be a need to test for titanium, which is used in the construction of the femoral stem in total hip replacements. It is not possible to use quadrupole inductively coupled plasma mass spectrometry due to interferences.

Methods

Titanium was measured using inductively coupled plasma optical emission spectroscopy using the emission line at 336.1 nm and Y (internal standard) at 371.0 nm. Internal quality control materials were prepared for blood and serum and concentrations assigned using a sector field-inductively coupled plasma mass spectrometer. A candidate whole blood certified reference material was also evaluated.

Results

The method had detection and quantitation limits of 0.6 and 1.9 µg/L, respectively. The respective bias (%) and measurement uncertainty ( U) (k = 2) were 3.3% and 2.0 µg/L (serum) and − 1.0% and 1.4 µg/L (whole blood). The respective repeatability and intermediate precision (%) were 5.1% and 10.9% (serum) and 2.4% and 8.6% (whole blood). The concentration of titanium was determined in patients’ samples, serum (median = 2.4 µg/L, n = 897) and whole blood (median = 2.4 µg/L, n = 189). Serum is recommended for monitoring titanium in patients, since the concentration is higher than in whole blood and the matrix less problematic. In hip fluid samples, the concentrations were much higher (mean 58.5 µg/L, median 5.1 µg/L, n = 83).

Conclusions

A method based on inductively coupled plasma optical emission spectroscopy was developed and validated for measuring titanium in clinical samples.

Trace metal determination as it relates to metallosis of orthopaedic implants: Evolution and current status

In utilising metal surfaces that are in constant contact with each other, metal-on-metal (MoM) surgical implants present a unique challenge, in the sense that their necessity is accompanied by the potential risk of wear particle generation, metal ion release and subsequent patient toxicity. This is especially true of orthopaedic devices that are faulty and subject to failure, where the metal surfaces undergo atypical degradation and release even more unwanted byproducts, as was highlighted by the recent recall of orthopaedic surgical implants. The aim of this review is to examine the area of metallosis arising from the wear of MoM articulations in orthopaedic devices, including how the surgical procedures and detection methods have advanced to meet growing performance and analytical needs, respectively.

Quantification of titanium from TiO2 particles in biological tissue

This study presents the development of a strategy for the quantification of titanium from titanium dioxide polydisperse particles (TiO2) in dry biological tissue. Calf liver was chosen as laboratory testing material. The challenge was to (i) obtain a complete mineralization of the solid material (biological tissue and TiO2) and (ii) ensure the accuracy of the determined concentrations with a sufficient sensitivity. Mineralization was performed using a mixture of concentrated nitric and hydrofluoric acids. Atomic mass spectrometry associated with light-scattering technique was used to control the physical state (dissolved and particle forms) of titanium and reliably estimate the total titanium concentration in calf liver. The monitoring of (46)Ti and (49)Ti, operating in helium collision/reaction cell mode, and using external calibration with internal standard addition, allowed the quantification of Ti while removing isobaric interferences. The limit of detection and quantification were 0.7 and 2.3μg (Ti)g(-1) (tissue) respectively. The mean analytical recovery over the whole procedure was (103±6)% in a range of concentrations from LOD to 200μg(Ti)g(-1) (tissue).

Inductively coupled plasma - Tandem mass spectrometry (ICP-MS/MS): A powerful and universal tool for the interference-free determination of (ultra)trace elements – A tutorial review

This paper is intended as a tutorial review on the use of inductively coupled plasma - tandem mass spectrometry (ICP-MS/MS) for the interference-free quantitative determination and isotope ratio analysis of metals and metalloids in different sample types. Attention is devoted both to the instrumentation and to some specific tools and procedures available for advanced method development. Next to the more typical reaction gases, e.g., H2, O2 and NH3, also the use of promising alternative gases, such as CH3F, is covered, and the possible reaction pathways with those reactive gases are discussed. A variety of published applications relying on the use of ICP-MS/MS are described, to illustrate the added value of tandem mass spectrometry in (ultra)trace analysis.

Determination of selenium in serum in the presence of gadolinium with ICP-QQQ-MS

Triple–quadrupole ICP-MS using O₂mass-shift technology is superior for removing gadolinium interference on selenium in serum.

Interference-free determination of ultra-trace concentrations of arsenic and selenium using methyl fluoride as a reaction gas in ICP-MS/MS

Interference-free conditions, allowing straightforward As and Se determination, can be obtained by using CH3F (a mixture of 10% CH3F and 90% He) as a reaction gas in tandem ICP-mass spectrometry (ICP-MS/MS). Both target elements react via CH3F addition and subsequent HF elimination, rendering AsCH2 (+) and SeCH2 (+) the respective favored reaction product ions. Instrumental limits of detection were 0.2 ng L(-1) for As and below 10 ng L(-1) for Se, using either (77)Se, (78)Se, or (80)Se. Neither addition of carbon to the solutions, nor admixing of additional He into the octopole reaction cell resulted in a further improvement of the LoDs, despite the increase in analyte signal intensity. By using synthetic matrices, containing elements giving rise to ions interfering at either the original mass-to-charge ratios or those of the reaction products, absence of spectral overlap could be demonstrated. This conclusion was corroborated by successful As and Se determination in a collection of reference materials from plant, animal, or environmental origin, displaying a considerable range of As and Se contents. These accurate results were obtained via external calibration using Te as an internal standard. The high efficiency reaction between As and CH3F and the possibility to use the major isotope of Se provides enhanced detection power versus other techniques, such as sector-field ICP-mass spectrometry, while the possibility to monitor at least three Se isotopes interference-free also enables isotopic analysis.

Potential of methyl fluoride as a universal reaction gas to overcome spectral interference in the determination of ultratrace concentrations of metals in biofluids using inductively coupled plasma-tandem mass spectrometry

Methyl fluoride (a mixture of 10% CH3F and 90% of He) was evaluated as a reaction gas in inductively coupled plasma-tandem mass spectrometry (ICPMS/MS) in the context of the determination of ultratrace concentrations of medically relevant metals (Al, Co, Cr, Mn, Ni, Ti, and V) in blood serum and urine. Via product ion scanning, whereby only ions of the mass-to-charge ratio of the target nuclide were admitted into the octopole reaction cell, the various reaction product ions formed for each of the target elements were identified at different CH3F gas flow rates. Limits of detection (LODs) and of quantification (LOQs) and linearity of the calibration curve were documented under (i) optimized ICPMS/MS conditions for single-element monitoring and (ii) compromise conditions, allowing for multielement determination. Even under compromise settings, instrumental LODs were below 10 ng/L for all target elements, while the use of CH3F provided interference-free conditions for their determination in the biofluids of interest. Quantitative data obtained for Seronorm blood serum and urine reference materials were in excellent agreement with the corresponding reference values and/or results obtained using double-focusing sector-field ICPMS (for those elements for which no certified values were available or that were affected during reconstitution), proving the potential of this reaction gas for multielement ultratrace analysis via ICPMS/MS.

Potential release of in vivo trace metals from metallic medical implants in the human body: from ions to nanoparticles--a systematic analytical review

Metal ion release from metallic materials, e.g. metallic alloys and pure metals, implanted into the human body in dental and orthopedic surgery is becoming a major cause for concern. This review briefly provides an overview of both metallic alloys and pure metals used in implant materials in dental and orthopedic surgery. Additionally, a short section is dedicated to important biomaterials and their corrosive behavior in both real solutions and various types of media that model human biological fluids and tissues. The present review gives an overview of analytical methods, techniques and different approaches applied to the measurement of in vivo trace metals released into body fluids and tissues from patients carrying metal-on-metal prostheses and metal dental implants. Reference levels of ion concentrations in body fluids and tissues that have been determined by a host of studies are compiled, reviewed and presented in this paper. Finally, a collection of published clinical data on in vivo released trace metals from metallic medical implants is included.

Utilization of triangle nanosilver to prepare spherical nanosilver and quantitatively detect trace titanium by SERS

The blue triangle nanosilver (BAgNP) sol was prepared by the two reducers of NaBH4 and H2O2. Using BAgNP as the precursor, a small spherical nanosilver (AgNP) sol in yellow was synthesized by addition of suitable amounts of X (-) (X = Cl, Br, and I). The oxidization process of BAgNP to AgNP was studied in detail by resonance Rayleigh scattering (RRS), surface-enhanced Raman scattering (SERS), laser scattering, surface plasmon resonance (SPR) absorption, and microscope techniques. It has been observed that NaCl accelerated the oxidizing BAgNP to form AgNP, and an oxidizing mechanism and quasi-nanograting Raman-scattering enhanced mechanism were developed to explain the phenomena. Using the BAgNP sol as substrate and based on the catalysis of Ti(IV) on the BrO3 (-) oxidizing safranine T (ST) molecular probe with a strong SERS peak at 1,535 cm(-1), a new catalytic SERS quantitative method was developed for the determination of 1.0 to 100 ng/mL Ti, with a detection limit of 0.4 ng/mL.