{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T19:05:28Z","timestamp":1777489528700,"version":"3.51.4"},"reference-count":34,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2021,9,20]],"date-time":"2021-09-20T00:00:00Z","timestamp":1632096000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Two cheap, simple and reproducible methods for the electrophoretic determination of homocysteine thiolactone (HTL) in human urine have been developed and validated. The first method utilizes off-line single drop microextraction (SDME), whereas the second one uses off-line SDME in combination with field amplified sample injection (FASI). The off-line SDME protocol consists of the following steps: urine dilution with 0.2 mol\/L, pH 8.2 phosphate buffer (1:2, v\/v), chloroform addition, drop formation and extraction of HTL. The pre-concentration of HTL inside a separation capillary was performed by FASI. For sample separation, the 0.1 mol\/L pH 4.75 phosphate buffer served as the background electrolyte, and HTL was detected at 240 nm. A standard fused-silica capillary (effective length 55.5 cm, 75 \u03bcm id) and a separation voltage of 21 kV (~99 \u03bcA) were used. Electrophoretic separation was completed within 7 min, whereas the LOD and LOQ for HTL were 0.04 and 0.1 \u03bcmol\/L urine, respectively. The calibration curve in urine was linear in the range of 0.1\u20130.5 \u03bcmol\/L, with R2 = 0.9991. The relative standard deviation of the points of the calibration curve varied from 2.4% to 14.9%. The intra- and inter-day precision and recovery were 6.4\u201310.2% (average 6.0% and 6.7%) and 94.9\u2013102.7% (average 99.7% and 99.5%), respectively. The analytical procedure was successfully applied to the analysis of spiked urine samples obtained from apparently healthy volunteers.<\/jats:p>","DOI":"10.3390\/molecules26185687","type":"journal-article","created":{"date-parts":[[2021,9,21]],"date-time":"2021-09-21T22:34:01Z","timestamp":1632263641000},"page":"5687","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["The Use of Single Drop Microextraction and Field Amplified Sample Injection for CZE Determination of Homocysteine Thiolactone in Urine"],"prefix":"10.3390","volume":"26","author":[{"given":"Krystian","family":"Purgat","sequence":"first","affiliation":[{"name":"Department of Environmental Chemistry, Faculty of Chemistry, University of Lodz, 163 Pomorska Str., 90-236 Lodz, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Izabella","family":"Ko\u015bka","sequence":"additional","affiliation":[{"name":"Department of Environmental Chemistry, Faculty of Chemistry, University of Lodz, 163 Pomorska Str., 90-236 Lodz, Poland"},{"name":"Doctoral School of Exact and Natural Sciences, University of Lodz, 12\/16 Banacha Str., 90-237 Lodz, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6080-5762","authenticated-orcid":false,"given":"Pawe\u0142","family":"Kubalczyk","sequence":"additional","affiliation":[{"name":"Department of Environmental Chemistry, Faculty of Chemistry, University of Lodz, 163 Pomorska Str., 90-236 Lodz, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,9,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Jakubowski, H. 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