ABSTRACT
Hydrogen sulfide is a toxic gas but also established as a naturally occurring gaseous signaling molecule in humans, playing key physiological roles with particular involvement in lung disease including COVID-19. Thiosulfate is the conventional biomarker of hydrogen sulfide and is excreted in human urine at low micromolar levels. Thiosulfate is amenable to detection by the element-selective inductively coupled plasma tandem mass spectrometry (ICPMS/MS), but sulfur speciation in human samples at trace levels is challenging due to the high complexity of human sulfur metabolome and the utility of this detector under such settings has not been demonstrated. We report a method for thiosulfate determination in human urine at trace physiological levels by HPLC-ICPMS/MS. The method involved one-step derivatization to improve chromatographic behavior followed by direct injection. The instrumental limit of detection was 1.4 μg S L−1 (0.02 μM or 0.1 pmol). In a group of samples from volunteers (n = 24), measured thiosulfate concentrations in the diluted urine matrix were down to 8.0 μg S L−1 with a signal-to-noise ratio >10. The method was validated for recovery (80–110%), repeatability (RSD% <5%), and linearity (r2 = 0.9999, at a tested working concentration range of 0.01–1.0 mg S L−1), and the accuracy was assessed by comparing with HPLC-ESIMS/MS which showed agreement within ±20%. This work demonstrates the applicability of HPLC-ICPMS/MS for sulfur speciation at trace levels in a matrix with complex sulfur metabolome as human urine and provides a sensitive method for the determination of the hydrogen sulfide biomarker. © 2022 The Authors
ABSTRACT
Urine source separation, a kind of new sewage management concept, has made great progress in technology development and application in the past 30 years. However, understanding of the potential microbial risks in reuse of urine derived fertilizer products (UDFPs) in agriculture is still lacking. Outbreak of pandemic of Coronavirus Disease 2019 and more deadly disease caused by Monkeypox strongly sounds the alarm bell to the attention on pathogens in urine and their fate in UDFPs. Therefore, this study presented a comprehensive review on pathogens inactivation in nutrient recovery technologies. The review suggests that technologies using alkaline or heating treatment can effectively reduce pathogens in UDFPs. However, technologies with characteristics such as membrane rejection of nutrients or nutrient adsorption may even concentrate pathogens in their fertilizer products. Based on an overall assessment, connections of technologies and the pathogens inactivation in their UDFPs have been established. This would help to provide a perspective on development of urine treatment technology and management of microbial risks in reusing urine nutrients in agriculture.
ABSTRACT
Aim: For oncolytic virus trials, regulatory agencies often require pharmaceutical industry to evaluate risks of released viruses from patients to environment. This study was to establish a real-time PCR method to assess viral shedding and viral stability in human urine. Results/methodology: Herein, we describe an incubation of viral drug product in human urine and use of real-time PCR as a simple, efficient and high throughput assay to assess the level and stability of a nonenveloped and single stranded RNA virus. The viral stability issue is critical to the collection, transport, storage and testing of clinical samples. Discussion/conclusion: In summary, this simple method provides useful viral stability information at various temperatures and detergents. A similar approach may apply to other RNA viruses (including SARS-CoV-2).