Medical application of laser-induced breakdown spectroscopy (LIBS) for assessment of trace element and mineral in biosamples: Laboratory and clinical validity of the method.

BACKGROUND: Biomedical application is based on the use of LIBS-derived data on chemical contents of tissues in diagnosis of diseases, forensic investigation, as well as a mechanism for providing online feedback for laser surgery. Although LIBS has certain advantages, the issue of correlation of LIBS-derived data on chemical element content in different human and animal tissues with other methods, and especially ICP-MS, remains pertinent. The objective of the present review was to discuss the application of laser-induced breakdown spectroscopy (LIBS) for elemental analysis of human biosamples or tissues from experimental models of human diseases. METHODS: A systematic search in the PubMed-Medline, Scopus, and Google Scholar databases using the terms laser-induced breakdown spectroscopy, LIBS, metals, trace elements, minerals, and names of particular chemical elements was performed up through 25 February, 2023. Of all extracted studies only those dealing with human subjects, human tissues, in vivo animal and in vitro cell line models of human diseases were reviewed in detail. RESULTS: The majority of studies revealed a wide number of metals and metalloids in solid tissues including teeth (As, Ag, Ca, Cd, Cr, Cu, Fe, Hg, Mg, Ni, P, Pb, Sn, Sr, Ti, and Zn), bones (Al, Ba, Ca, Cd, Cr, K, Mg, Na, Pb, Sr), and nails (Al, As, Ca, Fe, K, Mg, Na, P, Pb, Si, Sr, Ti, Zn). At the same time, LIBS was also used for estimation of trace element and mineral content in hair (Ca, Cu, Fe, K, Mg, Na, Zn), blood (Al, Ca, Co, Cd, Cu, Fe, Mg, Mn, Ni, Pb, Si, Sn, Zn), cancer tissues (Ca, Cu, Fe, Mg, K, Na, Zn) and other tissues. Single studies revealed satisfactory correspondence between quantitative LIBS and ICP-OES/MS data on the level of As (81-93 %), Pb (94-98 %), Cd (50-94 %) in teeth, Cu (97-105 %), Fe (117 %), Zn (88-117 %) in hair, Ca (97-99 %), Zn (90-95 %), and Pb (61-82 %) in kidney stones. LIBS also estimated specific patterns of trace element and mineral content associated with multiple pathologies, including caries, cancer, skin disorders, and other systemic diseases including diabetes mellitus type 2, osteoporosis, hypothyroidism, etc. Data obtained from in situ tissue LIBS analysis were profitably used for discrimination between tissue types. CONCLUSIONS: Taken together, the existing data demonstrate the applicability of LIBS for medical studies, although further increase in its sensitivity, calibration range, cross-validation, and quality control is required.

Monitoring of environmental persistent organic pollutants in hair samples collected from wild terrestrial mammals of Primorsky Krai, Russia.

Persistent organic pollutants (POPs) constitute a wide range of chemicals. Their release into the environment has raised great concern due to their potentially harmful impact in humans and wildlife species. The aim of this current study was to detect selected POPs in hair samples of wild terrestrial mammals from Primorsky Krai, Russia, so as to assess potential environmental exposure. The tested wild species were leopard cat, musk deer, wolf, amur hedgehog, and raccoon dog. The targeted organochlorines were hexachlorobenzene (HCB) and DDTs (opDDE, ppDDE, and opDDD), polychlorinated biphenyl (PCB) congeners (28, 52, 101, 118, 138, 153, and 180), and polycyclic aromatic hydrocarbons (PAHs) (acenaphylene (ACEN), fluorene (FLU), anthracene (ANTH) phenathrene (PHEN), and pyrene (PYR)). The detection of POPs was conducted in hair samples by a one-step hair extraction method, by using a headspace solid-phase microextraction technique (HS-SPME) and analyzed then by GC-MS. The majority of the wild animal hair samples were found positive in all tested pollutants. More specifically, the percentage of positive hair samples for HCB was 93.3% and for DDTs, PCBs, and PAHs, 20.0 to 100.0%, 6.7 to 100.0%, and 75.0 to 100.0%, respectively. DDT, PCB, and PAH detection ranged from 1.26 to 52.06 pg mg-1, 0.73 to 31.34 pg mg-1, and 2.59 to 35.00 pg mg-1, respectively. The highest mean concentration levels of all tested pollutants were found for musk deer (PCBs 12.41 pg mg-1, DDTs 21.87 pg mg-1, PAHs 22.12 pg mg-1) compared to the other wild species. To the best of our knowledge, this is the first study that provides results regarding contamination in different terrestrial mammals by POP exposure. The use of hair as a matrix is proven to be an effective tool for nondestructive biological monitoring of POP contamination in terrestrial ecosystems.

Comparative Evaluation of Drug Deposition in Hair Samples Collected from Different Anatomical Body Sites.

In this study, we focused on the validation of a method for the simultaneous detection and quantification of cannabinoids, cocaine and opiates in hair as well as on the distribution of the drugs deposition in hair collected from different anatomical body sites. The proposed analytical procedure was validated for various parameters such as selectivity, linearity, limit of quantification, precision, accuracy, matrix effect and recovery. Four hundred and eighty-one samples were collected during 2010-2015 from 231 drug abusers. A 6-h ultrasonic-assisted methanolic extraction was applied for the isolation of the drugs. The analysis was performed in an liquid chromatography-mass spectrometry system for the opiates and cocaine and in a gas chromatography-mass spectrometry system for the cannabinoids. Cocaine was the most frequent detected drug (68.8-80.5%) followed by cannabinoids (47.6-63.3%) and opiates (34.7-46.7%) depending on the body site that the samples were collected. The mean concentrations of Δ9-tetrahydrocannabinol (THC) were 0.63 ± 2.11 for head, 0.54 ± 1.03 for pubic, 0.34 ± 0.51 for axillary and 0.18 ± 0.18 ng/mg for chest hair samples. The values of cocaine were 6.52 ± 15.98, 4.64 ± 10.77, 6.96 ± 38.21 and 3.94 ± 6.35 ng/mg, while the values of 6-monoacetylmorphine (MAM) were 3.33 ± 5.89, 3.06 ± 9.33, 1.37 ± 1.37 and 16.4 ± 1.77 ng/mg for head, pubic, axillary and chest samples, respectively. Differences between the detected concentrations of cocaine and opiates between the hair samples of different anatomical sites, as well as the ratio of drug metabolites to the parent compounds were observed in some cases. Statistically significant differences in the mean detected levels were noticed for morphine and heroin between head and pubic hair and also for cocaine and benzoylecgonine, between head and axillary hair samples. Moreover, the ratio of MAM to morphine and THC to cannabinol seems to correlate statistically with the total opiate or cannabinoid detected concentrations. The above differences could be attributed to several parameters associated with the structure, morphology, growth rate and other characteristics of the collected hair.

Rapid method for the simultaneous determination of DDTs and PCBs in hair of children by headspace solid phase microextraction and gas chromatography-mass spectrometry (HSSPME/GC-MS).

The purpose of this study was to develop a rapid and cost efficient hair extraction method, using the headspace solid phase microextraction (HSSPME) technique for the simultaneous determination and biomonitoring of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane) (DDT) and its isomers/metabolites and polychlorinated biphenyls (PCBs) in hair samples. A total of 72 head hair samples were collected from children living in urban and rural regions of the island of Crete. Two hundred milligrams of hair were digested under alkaline conditions and thermostated for 30 min at 90°C while a 65 µm PDMS/DVB fibre was exposed into the headspace of the vial. Analytical parameters of the method (time of incubation, agitation speed, recovery, precision, accuracy, carry over, matrix effect, linearity, and selectivity) were examined. Recoveries of the DDTs in the spiked hair samples were calculated from 42.3% for opDDD to 87.1% for opDDE, while recoveries for PCB congeners were from 52.6% for PCB138 to 96.6 % for PCB28. The method was applied for the analysis of authentic hair samples. Significant differences (p=0.001) of the burden to total DDTs (sumDDTs) as well as of the frequencies of detection of positive samples (p=0.020) were observed between the examined regions. Moreover, significant differences in the detected concentrations of PCB congeners were observed for PCB52 (p<0.001) and PCB28 (p=0.017) as well for their prevalence between urban and rural regions. Application of HSSPME for the biomonitoring of DDTs and PCBs biomarkers in hair was tested and successfully applied to the analysis of spiked and authentic hair samples. HSSPME was found to be substantially simpler and faster procedure than previous reported sample treatment procedures.

Development and application of LC­APCI­MS method for biomonitoring of animal and human exposure to imidacloprid.

Imidacloprid (IMI) is a relatively new neuro-active neonicotinoid insecticide and nowadays one of the largest selling insecticides worldwide. In the present study a LC­APCI­MS based method was developed and validated for the quantification of imidacloprid and its main metabolite 6-chloronicotinic acid (6- CINA) in urine and hair specimens. The method was tested in biomonitoring of intentionally exposed animals and subsequently applied for biomonitoring of Cretan urban and rural population. The developed analytical method comprises two main steps of analytes isolation from specimen (solid­ liquid extraction with methanol for hair, liquid­liquid extraction with methanol for urine) and subsequent instrumental analysis by LC­APCI­MS. The developed method was applied for the monitoring of IMI and 6-ClNA in hair and urine of laboratory animals (rabbits) intentionally fed with insecticide at low or high doses (40 and 80 mg kg(-1) weight d(-1) respectively) for 24 weeks. The analytes were detected in the regularly acquired hair and urine specimens and their found levels were proportional to the feeding dose and time of exposure with the exception of slight decline of IMI levels in high dose fed rabbits after 24 weeks of feeding. This decline can be explained by the induction of IMI metabolizing enzymes by the substrate. After testing on animal models the method was applied for pilot biomonitoring of Crete urban (n = 26) and rural (n = 32) population. Rural but not urban population is exposed to IMI with 21 positive samples (65.6%) and found median concentration 0.03 ng mg(-1). Maximum concentration detected was 27 ng mg(-1)

Assessment of PCBs exposure in human hair using double focusing high resolution mass spectrometry and single quadrupole mass spectrometry.

Polychlorinated biphenyls (PCBs) levels were assessed in human hair samples, originating from two main agricultural regions of Greece. The analysis was performed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-double focusing high resolution mass spectrometry (GC-DFHRMS). The main analytical procedure involved hair decontamination, solid-liquid extraction and cleanup steps. The recoveries of PCBs ranged from 71.2% to 101.6%, with accuracies greater than 87.5% and the between-run precisions (%RSD) lower than 25% for all analytes. Differences in the frequencies of detection and the median values of PCBs were detected between the examined regions and between the applied analytical techniques. All Peloponnesus' hair examined samples were found positive for each examined PCB, while the percentage of the total positive samples ranged from 86.1% (for PCB 138) to 94.4% (for PCB 28 and 153 congeners) using GC-DFHRMS. The Cretan hair samples were less contaminated (SUM PCBs=0.61 and 1.47pg/mg) unlike the Peloponnesus' samples (SUM PCBs=24.68 and 38.74pg/mg) measured by GC-DFHRMS and GC-MS, respectively. PCBs with high chlorination gave lower concentration values compared to low chlorination PCBs in both populations. No significant differences were observed between women and men. The GC-DFHRMS technique provided higher percentage of positive samples and low PCBs median values, due to higher sensitivity and interferences from isobaric ions in the GC-MS technique and is therefore considered as a powerful tool for such assessments in hair specimens.

A novel photometric method for evaluation of the oxidative stability of virgin olive oils.

The Oxitester method, a novel, simple, and fast photometric method for the evaluation of the antioxidant capacity of olive oils, was validated and compared to the official oil stability index (Rancimat) method. The Oxitester method appeared to be a good alternative to the Rancimat method with adequate correlation for a wide range of virgin olive oil samples, including extrissima virgin olive oils (correlation coefficient 0.88), and extra virgin olive oils of increased acidity (free fatty acids >0.45%, correlation coefficient 0.89). Other quality factors (flavor, free fatty acids content, specific absorbance at 270 and 232 nm, peroxide value, and content of oleic, linoleic, and linolenic acids) were also measured and correlated to the antioxidant capacity values of the Oxitester and Rancimat methods. The Oxitester method, in contrast to the Rancimat method, was indicative of the flavor characteristics of the olive oils and the content of linolenic acid.