Detection of 11 carbamate pesticide residues in raw and pasteurized camel milk samples using liquid chromatography tandem mass spectrometry: Method development, method validation, and health risk assessment

This study aimed to use ultra-high-performance liquid chromatography coupled to a triple-quadrupole mass spectrometer to detect 11 carbamate pesticide residues in raw and pasteurized camel milk samples collected from the United Arab Emirates. A method was developed and validated by evaluating limits of detection, limits of quantitation, linearity, extraction recovery, repeatability, intermediate precision, and matrix effect. Due to the high protein and fat content in camel milk, a sample preparation step was necessary to avoid potential interference during analysis. For this purpose, 5 different liquid-liquid extraction techniques were evaluated to determine their efficiency in extracting carbamate pesticides from camel milk. The established method demonstrated high accuracy and precision. The matrix effect for all carbamate pesticides was observed to fall within the soft range, indicating its negligible effect. Remarkably, detection limits for all carbamates were as low as 0.01 μg/kg. Additionally, the coefficients of determination were >0.998, demonstrating excellent linearity. A total of 17 camel milk samples were analyzed, and only one sample was found to be free from any carbamate residues. The remaining 16 samples contained at least one carbamate residue, yet all detected concentrations were below the recommended maximum residue limits set by Codex Alimentarius and the European Union pesticide databases. Nonetheless, it is worth noting that the detected levels of ethiofencarb in 3 samples were close to the borderline of the maximum residue limit. To assess the health risk for consumers of camel milk, the hazard index values of carbofuran, carbaryl, and propoxur were calculated. The hazard index values for these 3 carbamate pesticides were all below 1, indicating that camel milk consumers are not at risk from these residues.

Immobilized Soybean Peroxidase Hybrid Biocatalysts for Efficient Degradation of Various Emerging Pollutants

In the present study, soybean peroxidase (SBP) was covalently immobilized onto two functionalized photocatalytic supports (TiO2 and ZnO) to create novel hybrid biocatalysts (TiO2-SBP and ZnO-SBP). Immobilization caused a slight shift in the pH optima of SBP activity (pH 5.0 to 4.0), whereas the free and TiO2-immobilized SBP showed similar thermal stability profiles. The newly developed hybrid biocatalysts were used for the degradation of 21 emerging pollutants in the presence and absence of 1-hydroxy benzotriazole (HOBT) as a redox mediator. Notably, all the tested pollutants were not equally degraded by the SBP treatment and some of the tested pollutants were either partially degraded or appeared to be recalcitrant to enzymatic degradation. The presence of HOBT enhanced the degradation of the pollutants, while it also inhibited the degradation of some contaminants. Interestingly, TiO2 and ZnO-immobilized SBP displayed better degradation efficiency of a few emerging pollutants than the free enzyme. Furthermore, a combined enzyme-chemical oxidation remediation strategy was employed to degrade two recalcitrant pollutants, which suggest a novel application of these novel hybrid peroxidase-photocatalysts. Lastly, the reusability profile indicated that the TiO2-SBP hybrid biocatalyst retained up to 95% degradation efficiency of a model pollutant (2-mercaptobenzothiazole) after four consecutive degradation cycles.

Laccases and peroxidases: The smart, greener and futuristic biocatalytic tools to mitigate recalcitrant emerging pollutants

Various organic pollutants so-called emerging pollutants (EPs), including active residues from pharmaceuticals, pesticides, surfactants, hormones, and personal care products, are increasingly being detected in numerous environmental matrices including water. The persistence of these EPs can cause adverse ecological and human health effects even at very small concentrations in the range of micrograms per liter or lower, hence called micropollutants (MPs). The existence of EPs/MPs tends to be challenging to mitigate from the environment effectively. Unfortunately, most of them are not removed during the present-day treatment plants. So far, a range of treatment processes and degradation methods have been introduced and deployed against various EPs and/or MPs, such as ultrafiltration, nanofiltration, advanced oxidation processes (AOPs) and enzyme-based treatments coupled with membrane filtrations. To further strengthen the treatment processes and to overcome the EPs/MPs effective removal dilemma, numerous studies have revealed the applicability and notable biocatalytic potentialities of laccases and peroxidases to degrade different classes of organic pollutants. Exquisite selectivity and unique catalytic properties make these enzymes powerful biocatalytic candidates for bio-transforming an array of toxic contaminants to harmless entities. This review focuses on the use of laccases and peroxidases, such as soybean peroxidase (SBP), horseradish peroxidase (HRP), lignin peroxidase (LiP), manganese peroxidase (MnP), and chloroperoxidase (CPO) as a greener oxidation route towards efficient and effective removal or degradation of EPs/MPs.

LC-MSMS based screening of emerging pollutant degradation by different peroxidases

Background

The presence of a wide range of bioactive organic pollutants in wastewater and municipal water sources is raising concerns about their potential effects on humans. Not surprisingly, various approaches are being explored that can efficiently degrade these persistent organic pollutants. Use of peroxidases has recently been recognized as a novel remediation approach that may have potential advantages over conventional degradation techniques. However, testing the abilities of different peroxidases to degrade diverse emerging pollutants is tedious and cumbersome.

Results

In the present study, we present a rapid and robust approach to easily test the degradability of 21 different emerging pollutants by five different peroxidases (soybean peroxidase, chloroperoxidase, lactoperoxidase, manganese peroxidase, and horseradish peroxidase) using an LC-MSMS approach. Furthermore, this approach was also used to examine the role of a redox mediator in these enzymatic degradation assays. Our results show that some of the organic pollutants can be easily degraded by all five of the peroxidases tested, whereas others are only degraded by a specific peroxidase (or when a redox mediator was present) and there are some that are completely resistant to degradation by any of the peroxidases tested (even in the presence of a redox mediator). The degradation of furosemide and trimethoprim by soybean peroxidase and chloroperoxidase, respectively, was investigated in detail by examining the transformation products generated during their degradation. Some of the products generated during enzymatic breakdown of these pollutants have been previously reported by others, however, we report many new transformation products.

Conclusions

LC-MSMS approaches, like the one described here, can be used to rapidly evaluate the potential of different peroxidases (and redox requirements) to be used as bioremediation agents. Our preliminary result shows peroxidases hold tremendous potential for being used in a final wastewater treatment step.

P3603Impact of idiopathic thrombocytopenic purpura on clinical outcomes in patients with acute myocardial infarction

Background

There is scarce evidence reflecting the clinical outcomes in patients with Idiopathic Thrombocytopenic Purpura (ITP) and Acute Myocardial Infarction (AMI). The ITP patient population is at higher risk of bleeding complications due to low platelet counts and difficulty in managing their antiplatelet and anticoagulation therapy. In our study, we sought to assess clinical outcomes of ITP patients admitted with AMI using the US national inpatient sample (NIS) database.

Purpose

To determine difference in in-hospital mortality, clinical complications, and length of stay (LOS) in AMI patients with and without ITP.

Methods

We identified adults aged ≥18 years hospitalized from 2005 to 2014 with AMI as their primary diagnosis utilizing ICD-9 codes 410.0 to 410.92. Patients with ITP were identified using ICD-9 code 287.31. The primary outcome was in-hospital mortality. Secondary outcomes included coronary revascularization procedures (PCI and CABG), and in-hospital complications including bleeding (intracranial, epistaxis, GI, and GU bleeding, hematoma, and bleeding requiring transfusion), cardiac complications, transfusions, acute ischemic stroke (AIS), and LOS. A propensity-matched cohort accounting for demographic characteristics, comorbidities, and cardiovascular risk factors, was created to compare these outcomes. Patients with secondary causes of ITP such as HIV, pregnancy, sepsis, SLE, malignancy were excluded.

Results

A total of 1108034 AMI admissions, of which 1002 with ITP, were identified. In the unmatched group, patients with ITP were older, and had more comorbidities (diabetes mellitus; hypothyroidism; atrial fibrillation; previous history of cardiovascular, peripheral, and end stage renal disease; all p<0.05). In the AMI population, 851 ITP and 851 non-ITP admissions were propensity-matched. Figure 1 illustrates the primary and secondary outcomes of the study among the propensity-matched study groups. Although there was no difference in short-term mortality between the ITP and non-ITP patients with AMI, patients with ITP were less likely to undergo coronary revascularization possibly because of thrombocytopenia. Patients with ITP had significantly more bleeding complications and transfusions. We observed in our study that patients with ITP had a significantly longer LOS compared to non-ITP patients (6.1 vs 5.4 days, with a mean ratio of 1.14 (95% CI: 1.05,1.23)).

Conclusion

In the large population of patients included in the NIS database, patients with ITP admitted with AMI, have a significantly higher rate of bleeding complications, undergo less PCI and have a longer LOS compared to AMI patients without ITP. There are no current guidelines by ACC/AHA/ESC regarding management of patients with AMI and thrombocytopenia. These results warrant further investigation through randomized controlled trials including patients with thrombocytopenia to assess long term outcomes and to define optimal management in this population.