UPLC-MS/MS method validation of ciprofloxacin in human urine: Application to biodegradability study in microbial fuel cell

Optimizations of the Conditions for Ceftobiprole Determination in a Complex Matrix

A quick and accurate chromatographic–densitometric method for the determination of ceftobiprole in biological material (whole blood and urine) was developed. Preparation of the test sample required extraction of the drug from the matrix and was carried out by testing methanol or acetone as extracting agents, which were successfully used to isolate ceftobiprole from biological material. Under optimization of the procedure, various stationary and mobile phases were tested. Lastly, HPTLC cellulose plates and a mixture containing ethanol, 2-propanol, glacial acetic acid, and water in the ratio 4:4:1:3 (v/v/v/v) were chosen. Densitometric detection was made at a maximum absorbance of 316 nm. The developed method was validated; a linear function of the ceftobiprole concentration was obtained in the range of 2.4–72 µg/mL (r > 0.99) for both methanol and acetone solutions. The average accuracy of the devised method was measured at nearly 100%; nevertheless, the limit of the quantification was at 8.92 for methanol and 9.14 µg/mL for acetone solution. Therefore, the above method can be successfully used to ceftobiprole in biological material.

Simultaneous Analysis of Vanillin and Coumarin in Mangrove Plants and Commercial Food Products Using UPLC-ESI-MS/MS

Background:

Vanillin is a key constituent of natural vanilla. Usage of natural vanilla is affected due to its high price and limited supply, which leads to the use of artificial vanilla flavoring substances. Coumarin is a commonly encountered adulterant in beverage, food, and cosmetics as a flavoring and fragrance enhancer. However, coumarin has been banned for use as a food additive due to its toxic effects. To comply with the quality of vanillin in food and food products needs to be ensured.

Methods:

A rapid, simple and selective analytical method has been developed and validated using ultra-high performance liquid chromatography-tandem mass spectrometry for quantitative analysis of vanillin and coumarin. We also optimized fragmentation pattern of these metabolites while increasing collision energy to elucidate its structural information. The suitability and robustness of the method was checked by Zorbax Eclipse XDB C8 column (4.6 × 150 mm, 5 μm) using mobile phase comprising of methanol (A) and water with 0.1% formic acid (B) (90:10) with a flow rate 200 μL/min. The separation was achieved within 4.2 min with total run time of 5.0 min. The analysis was done by multiple reaction monitoring using 153/93 and 147/91 pair transition in positive electrospray ionization for vanillin and coumarin respectively.

Results:

The lower limit of quantification of vanillin and coumarin was 0.39 ng/mL and 3.9 ng/mL respectively. The intra and inter-day precisions for vanillin and coumarin were lower than 8.87 and 8.62 whereas, accuracy was within ± 2.13 and ± 1.53 respectively. The vanillin and coumarin was found to be stable under the examined conditions. This method was successfully applied for quantification of vanillin and coumarin in mangrove species and commercial food products.

Conclusion:

The described method and fragmentation pattern could be useful to direct confirmation and quality monitoring of a commercial food products assimilated with vanillin.

Probing the degradation of pharmaceuticals in urine using MFC and studying their removal efficiency by UPLC-MS/MS

Nutrient recovery from source-separated human urine has attracted interest as it is rich in nitrogen and phosphorus that can be utilized as fertilizer. However, urine also contains pharmaceuticals, steroid hormones, etc. and their removal is crucial as they have detrimental effects on the environment and human health. The current study focuses on investigating the degradation of pharmaceuticals using a double-chamber microbial fuel cell (MFC). Urine was spiked with four pharmaceuticals (trimethoprim, lamivudine, levofloxacin, and estrone) at a concentration of 2 μg/mL. The MFC was operated for 7 months in batch mode with this spiked urine as feed. The degradation efficiency of the MFC was studied, for which a selective liquid chromatography-tandem mass-spectrometric method was developed for the quantitation of compounds used in the spiking experiments and was validated with a lower limit of quantification of 0.39 ng/mL. The maximum removal rate achieved was 96% ± 2%. The degradation mechanism involved processes like sorption and anoxic biodegradation. The voltage curve obtained showed that the presence of pharmaceuticals had an initial negative impact on power generation along with increased organic content; however, after the reactor acclimatization, increased power output was achieved with maximum organics removal at 30 h of retention time. This work opens a new perspective for the anoxic biodegradation of pharmaceuticals and can be useful in future bioremediation studies.

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Biodegradation of the pharmaceuticals was shown in urine using MFC system.

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MFC experiment conducted with urine spiked with four pharmaceuticals belonging to different class.

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The developed LCMS method was used to quantify the rate of degradation.

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Maximum degradation rate of 96 ± 2% was achieved.

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The microbial oxidation of organics in MFC suggest that it can be a promising technology for pharmaceuticals degradation from urine.