Qualitative and Quantitative Analysis of Contaminants of Emerging Concern in Biosolids Using a Dilute and Shoot UHPLC-Orbitrap MS Method

Significance of the Topic

Contaminants of emerging concern such as pharmaceuticals personal care products and endocrine disrupting chemicals persist in biosolids and pose environmental and health risks. High resolution analysis enables comprehensive assessment of known targets and non targeted transformation products to inform treatment evaluation and ecological impact.

Objectives and Study Overview

This study aimed to develop a full scan high resolution accurate mass LC MS workflow for simultaneous quantitative analysis of 49 targeted contaminants and non targeted screening of 381 compounds in biosolids and biosolid amended soils collected over several months.

Methodology

• Sample Preparation: Biosolid and biosolid amended soil samples were air dried sieved and homogenized. Five gram aliquots were extracted twice with 20 mL acetonitrile water mixture containing acetic acid EDTA and isotopically labeled surrogates using ultrasonic agitation and centrifugation. Combined extracts were reduced to dryness and reconstituted in 100 microliter internal standard solution prior to injection.
• Chromatography and Mass Spectrometry: Extracts were separated on a Thermo Scientific Dionex UltiMate 3000 HPLC system using positive mode on a Betasil column and negative mode on a Hypersil GOLD column with optimized gradients. Detection employed a Thermo Scientific Exactive Plus Orbitrap with heated electrospray interface operated at 140000 resolution in full scan mode in positive and negative polarities.
• Data Analysis: Quantitative analysis of 56 PPCPs used Thermo Scientific TraceFinder with a 5 ppm mass extraction window and retention time matching. Suspect screening of 381 CECs employed predicted adduct lists isotopic pattern matching and area thresholds. Results were further reviewed in Thermo Scientific SIEVE with ChemSpider integration.

Used Instrumentation

• Thermo Scientific Dionex UltiMate 3000 HPLC
• Thermo Scientific Exactive Plus Orbitrap MS with HESI II
• Betasil and Hypersil GOLD LC columns
• Thermo Scientific TraceFinder and SIEVE software with ChemSpider database

Main Results and Discussion

Extraction optimization indicated comparable recoveries for acetonitrile water and methanol water mixtures with acetonitrile selected for ease of evaporation. Targeted performance for 49 analytes showed method detection limits from 6 to 572 ng per gram with recoveries between 50 and 140 percent and RSDs below 20 percent. Quantitative results revealed high part per billion levels of bisphenol A caffeine carbamazepine triclocarban and triclosan in all samples. Non targeted screening detected surfactants quaternary ammonium compounds phthalates synthetic musk steroid hormones and flame retardants illustrating the wide range of contaminants present in biosolids.

Benefits and Practical Applications

This dilute and shoot HRAM approach eliminates extensive cleanup enabling rapid throughput of targeted quantitation and non targeted screening in a single run. The method is suitable for environmental monitoring wastewater treatment evaluation soil amendment assessment and regulatory compliance studies.

Future Trends and Potential Applications

Advances in high resolution mass spectrometry data processing and expanding suspect libraries will enhance coverage of emerging contaminants. Integration with bioassays isotope labelling and automation will improve sensitivity and throughput. The approach can be extended to plant uptake studies and long term fate assessment in terrestrial environments.

Conclusion

A rapid high resolution dilute and shoot workflow was established for the quantitative determination of targeted contaminants and broad suspect screening in biosolids. The method demonstrated robust performance highlighted the presence of diverse micropollutants and offers a practical tool for environmental assessment with ongoing expansion to include additional analytes.

References

1. Ternes T A and Joss A Eds Human Pharmaceuticals Hormones and Fragrances The Challenge of Micropollutants IWA 2006 p 443
2. Kortenkamp A Environmental Health Perspectives 2007 1 42