An Ultrasensitive (Parts-Per-Quadrillion) and SPE-Free Method for the Quantitative Analysis of Estrogens in Surface Water

Abstract

An analytical method is presented here that is sensitive to the parts-per-quadrillion (pg/L) for estrogens in surface water. The estrogens included for study were estrone, 17β-estradiol, estriol, 17α-ethinylestradiol, and equilin. The method consisted of the small-scale liquid-liquid extraction of surface water followed by derivation with dansyl chloride. Analyte separation and detection were performed by high-pressure liquid-chromatography and tandem mass-spectrometry. A large volume (100 μL) of the sample was injected on-column to increase the analyte mass sent to the detector. The detection limits of the method were 0.045 ng/L for estrone, 0.086 ng/L for 17β-estradiol, 0.030 ng/L for estriol, 0.049 ng/L for 17α-ethinylestradiol, and 0.13 ng/L for equilin. The whole-method accuracy ranged from 93 ± 5.8% to 105 ± 4.5% for all the analytes at two different spike levels. Similarly, the precision of the method was less than 8.0% relative standard deviation. The final method was used to analyze a series of samples from the Mississippi River spanning 51 river miles. Estrone was detected in all of the samples and 17β-estradiol was detected in one. Concentrations of estrone ranged from between the detection and quantification limits up to 0.63 ng/L. Increases in the concentration of estrone could be observed downstream from potential sources including a drinking water treatment plant. 17β-estradiol was detected below its quantitation limit in a sample taken downstream from a wastewater treatment plant.

Rapid and sensitive determination of multiple endocrine‐disrupting chemicals by ultrasound‐assisted in situ derivatization dispersive liquid–liquid microextraction coupled with ultra‐high‐performance liquid chromatography/tandem mass spectrometry

“…LODs obtained by the proposed method were compared with that obtained by other approaches and the results were listed in Table . As can be seen, the LODs of 23 EDCs obtained by the proposed method were lower by about 1–4 orders of magnitude than those obtained by conventional GC/MS/MS methods and LC/MS/MS, and comparable with some works in which mass spectrometry was applied as the detector.…”

A novel mass spectrometric method for formaldehyde in children's personal‐care products and water via derivatization with acetylacetone

“…The method reporting limit was defined as greater or equal to 3 times the analyte concentration that can be detected with 99.5% confidence to be above the contamination level and is defined by the following equation: where [Background] is the grand mean of the formaldehyde contamination observed over the 4 days, t (n‐4,99.5%) is the Student's t‐value at n = 4 (or 12) degrees of freedom, and s total is the total standard deviation. The total standard deviation was calculated by first performing a one‐way analysis of variance on the contamination data to determine the within‐day and between‐day variances . The within‐ and between‐day variances were then propagated to determine the total variance (s total 2 ).…”

“…The total standard deviation was calculated by first performing a one-way analysis of variance on the contamination data to determine the within-day and between-day variances. [45] The withinand between-day variances were then propagated to determine the total variance (s total 2 ). After the determination of the method reporting limit, the water used for the preparation of reagents, standards, and samples was switched to deionized water that had been boiled for 40-60 min.…”

Detection, Occurrence and Fate of Emerging Contaminants in Agricultural Environments

“…For example, Backe (2015) presents an ultrasensitive method for the detection of estrogens (17β-estradiol, estrone, estriol, 17α-ethinylestradiol, and equilin) in surface water which utilized liquid-liquid extraction followed by dansyl chloride derivatization and large volume injection (100 μL) coupled to liquid chromatography tandem mass spectrometry (LC-MS/MS). Detection limits ranging from 0.030 ng/L for estriol to 0.13 ng/L for equilin with accuracies ranging from 93±5.8% to 105±4.5%.…”