•D/H measurements of alkenones from saline and hypersaline lakes in North America.•We estimate the magnitude of D/H fractionation between lake water and alkenones.•Minimal sensitivity of D/H fractionation to salinity for lacustrine alkenones.•Contrasts results from marine alkenone producers.We present a preliminary assessment of the hydrogen isotopic composition of individual alkenones (C37–39 di-, tri- and tetra-unsaturated methyl- and ethyl-ketones) purified from surface lake sediment from sites spanning a range of salinities from 20 to 133 ppt. Combining these measurements with measurements of the hydrogen isotopic composition of modern lake water, we estimate the magnitude of D/H fractionation across our sample set and observe reduced sensitivity to salinity compared to observations from Emiliania huxleyi and Gephyrocapsa oceanica. This lends support to the hypothesis that D/H fractionation during biosynthesis is less sensitive to changes in salinity in alkenone producers from continental interior sites than in producers from open marine environments. We also observe stronger correlations between the tetra-unsaturated alkenone δD values with water δD values, and associated α values with salinity than we do for the di- and tri-unsaturated compounds, and suggest that this may result from increased number of lacustrine haptophyte species producing the di- and tri-unsaturated as compared to the tetra-unsaturated.

Highlights•Three lipid purification methods are presented for hydrogen isotope analysis.•The speed of sample throughput is greatly increased over published methods.•The potential for inadvertent H isotope fractionation is decreased.•Application to many sediment samples demonstrates the method effectiveness.Three methods are presented on how to purify acetylated sterols, acetylated triterpenols and individual alkenones for hydrogen isotope analysis from marine and lacustrine sediments using reverse-phase high performance liquid chromatography (RP-HPLC). The main advantages over previous HPLC methods are reduced operator time, increased automation and the ability to simultaneously purify multiple target compounds from a sample. These gains are achieved primarily by acetylating compounds prior to purification rather than after, and also by using a fraction collector with semi-preparatory rather than analytic configuration. The effectiveness of the method is demonstrated for (i) dinosterol and taraxerol in sediment from the brackish pond Poza del Diablo, Galápagos, (ii) for di- and tri-unsaturated C37 and C38 alkenones in cultured Emiliania huxleyi, (iii) for brassicasterol, and di-, tri- and tetra-unsaturated C37 alkenones in sediment from Manito Lake, Saskatchewan, Canada, and (iv) for brassicasterol, dinosterol and di-, tri- and tetra-unsaturated C37 alkenones in sediment from the Great Salt Lake, Utah. The purification process yields 80–90% recoveries and results in no measurable hydrogen isotope alteration.