Extraction Efficiency of a Commercial Espresso Machine Compared to a Stainless-Steel Column Pressurized Hot Water Extraction (PHWE) System for the Determination of 23 Pharmaceuticals, Antibiotics and Hormones in Sewage Sludge

Abstract

Two green chemistry extraction systems, an in-house stainless-steel column Pressurized Hot Water Extraction system (PHWE) and a commercially available Espresso machine were applied for analysing 23 active pharmaceutical ingredients (APIs) in sewage sludge. Final analysis was performed on UPLC-MS/MS using two different chromatographic methods: acid and basic. When analysing all 23 APIs in sewage sludge both extraction methods showed good repeatability. The PHWE method allowed for a more complete extraction of APIs that were more tightly bound to the matrix, as exemplified by much higher concentrations of e.g., ketoconazole, citalopram and ciprofloxacin. In total, 19 out of 23 investigated APIs were quantified in sewage sludge, and with a few exceptions the PHWE method was more exhaustive. Mean absolute recoveries of 7 spiked labelled APIs were lower for the PHWE method than the Espresso method. Under acid chromatographic conditions mean recoveries were 16% and 24%, respectively, but increased to 24% and 37% under basic conditions. The difference between the PHWE method and the Espresso method might be interpreted as the Espresso method giving higher extraction efficiency; however, TIC scans of extracts revealed a much higher matrix co-extraction for the PHWE method. Attempts were made to correlate occurrence of compounds in sewage sludge with chemical properties of the 23 APIs and there are strong indications that both the number of aromatic rings and the presence of a positive charge is important for the sorption processes to sewage sludge.

Analytical methodologies for the determination of pharmaceuticals and personal care products (PPCPs) in sewage sludge: A critical review

“…In the future, this green extraction technique is expected to help manipulate large sample sizes for industrial applications. Despite these commented advantages, only two references of the use of PHWE as the extraction technique was found in the last 6-years reviewed [87,144] along with one more [88] in the previous five-year period [14]. versatility.…”

Total Release of 21 Indicator Pharmaceuticals Listed by the Swedish Medical Products Agency from Wastewater Treatment Plants to Surface Water Bodies in the 1.3 Million Populated County Skåne (Scania), Sweden

“…Ciprofloxacin is known to adsorb to the sludge phase [ 47 ], and this probably explains why it was not detected in any wastewater outlets. In previous Swedish studies, ciprofloxacin has been quantified in sludge up to a few thousand µg/kg [ 47 , 48 ]. Stockholm Vatten [ 24 ] reported low concentrations of 20 ng/L (RSD = 50%) at Henriksdal and 40 ng/L (RSD = 44%) at Bromma.…”

“…In the same study, the effluent sample had maximum and average concentrations of 41 and 36 ng/L, respectively, which is slightly higher than previous Swedish studies. Ketoconazole was also recently quantified by us in sludge, showing concentrations as high as 3009 ng/kg [ 48 ]. Ketoconazole was not analyzed in the EU Monitoring [ 39 ].…”

From Sewage Sludge to the Soil—Transfer of Pharmaceuticals: A Review

“…The highest concentrations were recorded for antibiotics of the fluoroquinolone group, such as ofloxacin, the content of which was estimated at 8546.21 µg/kg dm [ 23 ]. Ciprofloxacin was estimated at 6500 µg/kg dm [ 24 ], 3726.8 µg/kg dm [ 25 ], and 303 µg/kg dm [ 26 ] while norfloxacin was estimated at 2796.68 µg/kg dm [ 23 ] and 620 µg/kg dm [ 24 ]. High concentrations were obtained for another group of antibiotics—tetracyclines.…”