Perspectives and challenges associated with the determination of new psychoactive substances in urine and wastewater - A tutorial

New psychoactive substances (NPS), often designed as (legal) substitutes to conventional illicit drugs, are constantly emerging in the drug market and being commercialized in different ways and forms. Their use continues to cause public health problems and is therefore of major concern in many countries. Monitoring NPS use, however, is arduous and different sources of information are required to get more insight of the prevalence and diffusion of NPS use. The determination of NPS in pooled urine and wastewater has shown great potential, adding a different and complementary light on this issue. However, it also presents analytical challenges and limitations that must be taken into account such as the complexity of the matrices, the high sensitivity and selectivity required in the analytical methods as a consequence of the low analyte concentrations as well as the rapid transience of NPS on the drug market creating a scenario with constantly moving analytical targets. Analytical investigation of NPS in pooled urine and wastewater is based on liquid chromatography hyphenated to mass spectrometry and can follow different strategies: target, suspect and non-target analysis. This work aims to discuss the advantages and disadvantages of the different data acquisition workflows and data exploration approaches in mass spectrometry, but also pays attention to new developments such as ion mobility and the use of in-silico prediction tools to improve the identification capabilities in high-complex samples. This tutorial gives an insight into this emerging topic of current concern, and describes the experience gathered within different collaborations and projects supported by key research articles and illustrative practical examples.

UHPLC-QTOF MS screening of pharmaceuticals and their metabolites in treated wastewater samples from Athens

After consumption, pharmaceuticals are excreted as parent compounds and/or metabolites in urine and faeces. Some are not completely removed during wastewater treatments, forcing sewage treatment plants (STPs) to apply alternative technologies to guarantee quality of treated water. To monitor the removal efficiency of STPs, not only unchanged compounds and metabolites have to be taken into account, but also formation of possible transformation products (TPs). In this work, QTOF MS has been used for screening metabolites/TPs of pharmaceuticals in effluent wastewater from Athens. A customised database was built with the exact masses of metabolites reported in literature for the parent drugs found in an initial screening. Additionally, TPs identified in previous degradation experiments performed at our laboratory were included. Up to 34 metabolites/TPs were detected for omeprazole, venlafaxine, clindamycin, clarithromycin, clopidogrel or dipyrone, among others. Seven corresponded to TPs whose reference standards were available at our lab, seven were TPs previously identified in laboratory degradation experiments, eight were TPs tentatively identified by QTOF MS without reference standards, and twelve TPs were discovered after using the common fragmentation pathway approach. Tentative identification of TPs was supported by prediction of their chromatographic retention time based on the use of advanced chemometric QSRR models.

Genome-wide identification and phylogenetic analysis of the SBP-box gene family in melons

The SBP-box gene family is specific to plants and encodes a class of zinc finger-containing transcription factors with a broad range of functions. Although SBP-box genes have been identified in numerous plants, including green algae, moss, silver birch, snapdragon, Arabidopsis, rice, and maize, there is little information concerning SBP-box genes, or the corresponding miR156/157, function in melon. Using the highly conserved sequence of the Arabidopsis thaliana SBP-box domain protein as a probe of information sequence, the genome-wide protein database of melon was explored to obtain 13 SBP-box protein sequences, which were further divided into 4 groups, based on phylogenetic analysis. A further analysis centered on the melon SBP-box genetic family's phylogenetic evolution, sequence similarities, gene structure, and miR156 target sequence was also conducted. Analysis of all the expression patterns of melon SBP-box family genes showed that the SBP-box genes were detected in 7 kinds of tissue, and fruit had the highest expression level. CmSBP11 tends to present its specific expression in melon fruit and root. CmSBP09 expression was the highest in flower. Overall, the molecular evolution and expression pattern of the melon SBP-box gene family, revealed by these results, suggest its function differentiation that followed gene duplication.

Assessment of metal bioavailability in smelter-contaminated soil before and after lime amendment

In this study, changes in bioavailable concentrations of Pb, Zn, Cu and As in former smelter site soils (J1 and J2) were investigated before and after lime amendment. The immobilization efficiencies of metal(loid)s were evaluated by Toxicity Characteristic Leaching Procedure (TCLP). Their bioavailable concentrations in the soils were evaluated by the acid-extractable and -reducible fractions in Standard Measurement and Testing Program (i.e., SM&T(I+II)), in vitro physiologically based extraction test (PBET) and diffusive gradients in thin-films (DGT). The results showed that the bioavailable concentrations remarkably decreased after lime amendment in both J1 and J2 soils. DGT uptake and resupply (R) of Zn, Cu and As from soil to soil solution increased but that of Pb decreased. This pattern was consistent with SM&T(I+II)- and PBET-extractable concentrations after lime amendment. This indicates that lime amendment is highly effective for the immobilization of Zn, Cu and As, but not for Pb. Our results implicate that DGT can be used to estimate bioavailability of metal(loid)s in soils and further extended to estimate risk reduction after soil remediation.

Diffusive gradients in thin films (DGT) for the prediction of bioavailability of heavy metals in contaminated soils to earthworm (Eisenia foetida) and oral bioavailable concentrations

The applicability of diffusive gradients in thin-films (DGT) as a biomimic surrogate was investigated to determine the bioavailable heavy metal concentrations to earthworm (Eisenia foetida). The relationships between the amount of DGT and earthworm uptake; DGT uptake and the bioavailable concentrations of heavy metals in soils were evaluated. The one-compartment model for the dynamic uptake of heavy metals in the soil fitted well to both the earthworm (R(2)=0.641-0.990) and DGT (R(2)=0.473-0.998) uptake data. DGT uptake was linearly correlated with the total heavy metal concentrations in the soil (aqua regia), the bioavailable heavy metal concentrations estimated by fractions I+II of the standard measurements and testing (SM&T) and physiologically based extraction test (PBET, stomach+intestine). The coefficients of determination (R(2)) of DGT uptake vs. aqua regia were 0.433, 0.929 and 0.723; vs. SM&T fractions (I+II) were 0.901, 0.882 and 0.713 and vs. PBET (stomach+intestine) were 0.913, 0.850 and 0.649 for Pb, Zn and Cu, respectively. These results imply that DGT can be used as a biomimic surrogate for the earthworm uptake of heavy metals in contaminated soils as well as predict bioavailable concentrations of heavy metals estimated by SM&T (I+II) and PBET as a human oral bioavailable concentrations of heavy metals.

Systemic scleroderma: a spatiotemporal clustering

BACKGROUND AND AIMS

The aetiology of systemic scleroderma remains poorly understood. Twin studies suggest a low genetic input. Of the incriminated environmental agents, silica and vinyl chloride monomer exposure appear the most convincing. Spatiotemporal clustering has been demonstrated only three times previously. We now report a fourth cluster around Edenhope, western Victoria in terms of numerator and denominator estimates, cumulative incidence, distribution in time and space, and possible aetiological factors.

METHODS

Prevalence/cumulative incidence numerator and denominator values were obtained and validated. Each case was age-and gender-matched with two controls. A standardized postal questionnaire was used to obtain data on current, past history, family history, and occupational and non-occupational environmental exposure.

RESULTS

Six systemic scleroderma cases and one mixed connective tissue disease patient with a predominance of scleroderma features were identified. The 5-year cumulative incidence was 6.1/10,000, tenfold higher than the Sydney estimates for a similar, though non-identical time period. The gender ratio was 1:1. No cases were genetically related. A family history of scleroderma was validated in one instance and a family history of Raynaud's was noted in first degree relatives of two cases and one control. In all instances, Edenhope residence preceded disease onset. No one environmental agent was implicated in all cases.

CONCLUSION

A spatiotemporal cluster of systemic scleroderma was confirmed and validated. It occurred with a tenfold increased cumulative incidence to that expected and also extended beyond the initially defined 50 km radius of Edenhope. The cases identified were not related. Although no one specific environmental agent was identified, the spatiotemporal clustering would be compatible with an agent occurring at relatively high frequency, but with low disease conversion rates, such as silica inhalation (assuming sufficiently small particle size) or reaction to an infective agent.