The Brazilian Chemical Society – Special issue Foster Mesko, Marcia; Lopes, Norberto Peporine
Rapid communications in mass spectrometry,
September 2020, 2020-09-00, 20200901, Letnik:
34, Številka:
S3
Journal Article
A single analysis of hair for determining halogens (chlorine, bromine, fluorine, and iodine) and sulfur by ion chromatography with suppressed conductivity and mass spectrometry detection (IC-MS) was ...proposed. Inductively coupled plasma optical emission spectrometry (ICP OES) and inductively coupled plasma mass spectrometry (ICP-MS) were also used to compare the results. For this purpose, 300 mg of human hair were digested by microwave-induced combustion (MIC) using 20 bar of oxygen pressure. The analytes were absorbed in 100 mmol L
−1
NH
4
OH. Trueness of the proposed method was evaluated by analysis of a CRM of human hair; by recovery tests, using standard solution at two levels (50% and 100%), and by comparison of results with those obtained by ICP OES (Cl and S) and ICP-MS (Br and I). Suitable recoveries (ranging from 92 to 105%) were obtained, and the results from CRM analysis did not differ significantly from those described in the certificate. Moreover, results obtained by IC-MS did not present significant differences (
p
> 0.05) from those obtained by ICP OES and by ICP-MS. Precision was evaluated in terms of repeatability and intermediate precision, and the relative standard deviations were always lower than 8%. The proposed method presented good accuracy and it is a reliable strategy for human hair analysis. Final digests obtained using the MIC method were fully compatible with all proposed determination techniques. Compared to others reported in the literature, the proposed method presents several advantages, especially given that it is possible to determine halogens and sulfur in a single analysis.
Graphical abstract
•A method for As speciation by LC-ICP-MS/MS was developed.•A simple extraction method using diluted HNO3 solution was proposed.•No dilution was required to eliminate chlorine interferences on As ...determination.•This method has good sensitivity, selectivity, accuracy, precision and robustness.•As species in shark, shrimp, squid, oyster and scallop were determined.
A method for arsenic speciation in shark, shrimp, squid, oyster and scallop using liquid chromatography coupled to inductively coupled plasma triple quadrupole mass spectrometry (LC-ICP-MS/MS) was proposed. Suitable sensitivity and selectivity by LC-ICP-MS/MS were obtained using 10 mmol L−1 (NH4)2HPO4 diluted in 1% methanol (pH 8.65) as mobile phase. Recoveries from 90 to 104% for arsenobetaine (AsB), arsenite As(III), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA) and arsenate As(V) were obtained for all samples. A certificated reference material was also analyzed and the sum of As species was in agreement with the total As concentration. Limits of quantification (LOQ) for AsB, As(III), DMA, MMA, and As(V) were 6, 30, 6, 12 and 26 ng g−1, respectively. Higher concentration of AsB was found in all seafood, while As(III) and DMA were found only in oyster. Arsenate was found in squid and scallops, and MMA was below the LOQ in all samples.
Per and polyfluoroalkylated substances (PFAS) are common additives in ski waxes for their water repellent characteristic. Abrasion of ski wax leaves PFAS on the snow surface, however, little is known ...about the distribution and concentration of PFAS in snow and soil due to skiing. In this study we analysed different ski waxes, snowmelts and soil from family skiing areas from Alpine locations using targeted high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) to understand more about PFAS distribution in the environment. In general, we found a very diverse PFAS pattern in the analysed media. PFAS level was higher in skiing areas compared to the non-skiing ones that were used as control. ∑target PFAS ranged between <1.7 ng L
and 143 ng L
in snowmelt, <0.62 ng g
and 5.35 ng g
in soil and <1.89 and 874 ± 240 ng g
in ski wax samples. Snowmelt was dominated by short-chained PFAS, while soil and wax contained both short and long-chained PFAS. Extractable organic fluorine (EOF) was several orders of magnitude higher for waxes (0.5-2 mg g
) than for soils (up to 0.3 μg g
), while total fluorine (TF) content of the waxes was even higher, up to 31 210 ± 420 μg g
. We also showed that the ∑ target PFAS accounts for up to 1.5% in EOF content, showing that targeted LC-MS/MS gives a limited measure of the pollution originated from ski waxes and non-targeted analysis and EOF is necessary for a better overview on PFAS distribution.
Rationale
Bromine and iodine have important physiological functions; however, in inadequate concentration, they can also cause several physiological problems. Their mobility assessment in human ...organisms through biological sampling may help clarify some doubts related to metabolic routes, which are still not well elucidated. In this context, a suitable analytical method for this purpose should be developed.
Methods
An analytical method for determining ultratrace levels of bromine and iodine in human nail samples was developed. Inductively coupled plasma mass spectrometry (ICP‐MS) using a conventional nebulization system was immediately chosen as the determination tool because of its powerful sensitivity and selectivity. Sample preparation methods including microwave‐induced combustion (MIC), microwave‐assisted extraction, and microwave‐assisted digestion were evaluated. The compatibility of the final solutions with ICP‐MS analysis was considered while the method was developed.
Results
MIC was chosen as the most suitable method for the sample preparation for determining the levels of bromine and iodine in human nail samples using ICP‐MS. Unlike other sample preparation methods, this one fully eliminated interferences related to the carbon content and memory effects. Sample masses up to 100 mg were efficiently digested, and the analytes were quantitatively absorbed using only 50 mmol L−1 NH4OH solution. Recoveries ranged from 93% to 102%, and the relative standard deviation was < 8%.
Conclusions
The proposed analytical method presents important characteristics for routine analysis. It allows ultratrace determination even when low sample masses are used because of the low blank values, reduced volume of reagents, and powerful detectability using ICP‐MS.
Tens of millions of dried seahorses (genus Hippocampus) are traded annually, and the pressure from this trade along with their life history traits (involved parental care and small migration ...distances and home ranges) has led to near global population declines. This and other forms of overexploitation have led to all seahorse species being listed in Appendix II under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). The signatory nations of CITES recommended a 10-cm size limit of seahorses to ensure harvested individuals have reached reproductive maturity, and have thus had the chance to produce offspring, to maintain a more sustainable global seahorse fishery. We assessed adherence to CITES recommendations using DNA barcoding and size measurements to compare two prominent U.S. dried seahorse markets: (1) traditional Chinese medicine (TCM), and (2) non-medicinal ecommerce and coastal curio (ECC). We also estimated U.S. import abundance from CITES records. Of the nine species identified among all samples (n = 532), eight were found in the TCM trade (n = 168); composed mostly (75%) of the Indo-Pacific species Hippocampus trimaculatus, and Hippocampus spinosissimus, and the Latin American Hippocampus ingens. In contrast, ECC samples (n = 344) included 5 species, primarily juvenile Indo-Pacific Hippocampus kuda (51.5%) and the western Atlantic Hippocampus zosterae (40.7). The majority of TCM samples (85.7%) met the CITES size recommendation, in contrast to 4.8% of ECC samples. These results suggest non-size discriminatory bycatch is the most likely source of imported ECC specimens. In addition, CITES records indicate that approximately 602,275 dried specimens were imported into the U.S. from 2004-2020, but the exact species composition remains unknown as many U.S. imports records list one species or Hippocampus spp. from confiscated shipments due to difficulties in morphological identification and large numbers of individuals per shipment. Molecular identification was used to identify the species composition of confiscated shipment imports containing undesignated species, and similar to TCM, found H. trimaculatus and H. spinosissimus the most abundant. By combining DNA barcoding, size comparisons, and CITES database records, these results provide an important glimpse into the two primary dried U.S. seahorse end-markets, and may further inform the conservation status of several Hippocampus species.
Iron (Fe) is used in various cellular functions, and a constant balance between its uptake, transport, storage, and use is necessary to maintain its homeostasis in the body. Changes in Fe metabolism ...with a consequent overload of this metal are related to neurological changes and cover a broad spectrum of diseases, mainly when these changes occur during the embryonic period. This work aimed to evaluate the effect of exposure to Fe overload during the embryonic period of Drosophila melanogaster. Progenitor flies (male and female) were exposed to ferrous sulfate (FeSO4) for ten days in concentrations of 0.5, 1, and 5 mM. After mating and oviposition, the progenitors were removed and the treatment bottles preserved, and the number of daily hatches and cumulative hatching of the first filial generation (F1) were counted. Subsequently, F1 flies (separated by sex) were subjected to behavioral tests such as negative geotaxis test, open field test, grooming, and aggression test. They have evaluated the levels of dopamine (DA), serotonin (5-HT), octopamine (OA), tryptophan and tyrosine hydroxylase (TH), acetylcholinesterase, reactive species, and the levels of Fe in the progenitor flies and F1. The Fe levels of F1 flies are directly proportional to what is incorporated during the period of embryonic development; we also observed a delay in hatching and a reduction in the number of the hatch of F1 flies exposed during the embryonic period to the 5mM Fe diet, a fact that may be related to the reduction of the cell viability of the ovarian tissue of progenitor flies. The flies exposed to Fe (1 and 5 mM) showed an increase in locomotor activity (hyperactivity) and a significantly higher number of repetitive movements. In addition to a high number of aggressive encounters when compared to control flies. We can also observe an increase in the levels of biogenic amines DA and 5-HT and an increase in TH activity in flies exposed to Fe (1 and 5 mM) compared to the control group. We conclude that the hyperactive-like behavior demonstrated in both sexes by F1 flies exposed to Fe may be associated with a dysregulation in the levels of DA and 5-HT since Fe is a cofactor of TH, which had its activity increased in this study. Therefore, more attention is needed during the embryonic development period for exposure to Fe overload.
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•Progenitors flies exposed to Fe reduced ovarian cell viability.•F1 flies exposed to Fe in the embryonic period have increased DA, 5-HT and TH.•F1 Flies exposed to Fe in the embryonic period became hyperactive.•F1 Flies exposed to Fe in the embryonic period showed repetitive movements.
Non-motor alterations such as anxiety and memory deficit may represent early indications of Parkinson’s disease (PD), and therapeutic strategies that reduce non-motor alterations are promising ...alternatives for the treatment. Therefore, the search for natural compounds that act on motor and non-motor complications is highly relevant. In this sense, we demonstrated the role of hesperidin (Hsd) as a citrus flavonoid and its pharmacological properties as an antioxidant and neuroprotective agent. Our objective was to evaluate Hsd in developing motor and non-motor alterations in a Drosophila melanogaster model of Parkinson-like disease induced by iron (Fe) exposure. The flies were divided into six groups: control, Hsd (10 µM), L-dopa (positive control, 1 mM), Fe (1 mM), Fe + Hsd, and Fe + L-dopa. Motor coordination tests, memory assessment through aversive phototaxy, and anxiety-like behaviors characterized in flies, such as grooming and aggressiveness, were performed. The Hsd attenuated motor and non-motor alterations, such as motor coordination, memory deficits and anxiety-like behaviors, attenuated monoaminergic deficits, and lowered Fe levels in the head of flies. In addition, Hsd prolonged the life of the flies, thereby standing out from the L-dopa-treated group. Thus, Hsd can protect the dopaminergic system from insults caused by Fe, preventing non-motor alterations in PD; Hsd also reduced Fe levels in the flies’ heads, suggesting that iron chelation may represent an important mechanism of action, in addition to its antioxidant action.
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•Hsd protected the dopaminergic system from insults caused by Fe.•Hsd prevented the development of motor and non-motor alterations in a Parkinson’s disease model.•Hsd adjusted iron levels in the flies’ head.•Hsd adjusted tyrosine hydroxylase activity, which regulates dopamine and octopamine levels.•Hsd prolonged the lifespan of the flies, performing better than the L-dopa-treated group.
Neuroprotective effect of 4-PSQ through different mechanisms of action, by improving antioxidant defenses and consequently reducing oxidative damages, and by anticholinesterase action, factors that ...together can prevent dopamine depletion, actions correlated with the presence of selenium in the molecule of 4-PSQ.
Source: author’s personal archive.
Caption: Full arrows demonstrate the results obtained in this study. Dotted lines represent some hypotheses of possible pathways in the mechanism of action, however they were not performed in this study.
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•4-PSQ restores dopamine levels in fly heads.•4-PSQ improves ROT-induced mortality and locomotor deficits in flies.•4-PSQ reduces oxidative damage, improves antioxidant defenses, and exercises an anticholinesterase action.•Neuroprotective effects of 4-PSQ are correlated with selenium levels in fly heads.
Neurodegeneration in Parkinson's disease appears to be caused by multiple factors, including oxidative damage and an increase in acetylcholinesterase expression that can culminate in loss of dopaminergic neurons. A selenium-containing quinoline derivative, 7-chloro-4-(phenylselanyl) quinoline (4-PSQ), shows important pharmacological actions mainly attributed to its antioxidant and anticholinesterase properties. Thus, this study investigated the neuroprotective effect of 4-PSQ in a model of Parkinson’s-like disease induced by rotenone (ROT) in Drosophila melanogaster and verified whether these effects are related to selenium levels. Adult flies were divided into: 1 control, 2 4-PSQ (25 μM), 3 ROT (500 μM), and 4 4-PSQ (25 μM) + ROT (500 μM) groups and exposed to a diet containing ROT and/or 4-PSQ for 7 days, according to their respective groups. Survival, behavioral, and ex vivo analyses were performed. Dopamine levels, reactive species levels (RS), lipid peroxidation (LPO), superoxide dismutase (SOD) and catalase (CAT) activity, and proteic thiol (PSH) and non-proteic thiol (NPSH) content in the head region were analyzed, while acetylcholinesterase (AChE) activity and selenium levels in the head and body regions were analyzed. 4-PSQ was able to reverse the ROT-induced deficits in flies, reestablish dopamine and selenium levels, reverse cholinergic deficits, improve motor function, and ameliorate mortality. Furthermore, 4-PSQ also reduced RS levels and LPO, and restored the activities of the antioxidant enzymes, SOD and CAT. Interestingly, a positive relationship between dopamine and selenium levels could be seen. Our results demonstrate the neuroprotective effect of 4-PSQ, and we suggest that the compound may act via different mechanisms, such as improving antioxidant defenses and consequently reducing oxidative damages, as well as having an anticholinesterase action, which together can prevent dopamine depletion, as these actions were correlated with the presence of selenium in the 4-PSQ molecule.
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