A new combination for the determination of ultratrace cadmium: solid-phase microextraction by stearic acid-coated magnetic nanoparticles prior to batch-type hydride generation atomic absorption spectrometry Nursu Aylin Kasa & Erhan Akkaya & Buse Tuğba Zaman & Gülten Çetin & Sezgin Bakirdere Received: 17 May 2018 /Accepted: 5 September 2018 # Springer Nature Switzerland AG 2018 Abstract Solid-phase microextraction method based on stearic acid-coated magnetic nanoparticle has been combined with batch-type hydride generation atomic absorption spectrometry (BT-HGAAS) system to deter- mine cadmium at ultratrace levels. After the adsorption of cadmium ions onto stearic acid-coated magnetic nanoparticles, they were easily separated from the aque- ous phase by means of a magnet. All the instrumental and experimental parameters such as pH of buffer solu- tion, interaction period, concentration, and volume of NaBH 4 were optimized. Under the optimal conditions, limit of quantification (LOQ) and limit of detection (LOD) for the solid-phase microextraction (SPME) based on stearic acid-coated magnetic nanoparticles- BT-HGAAS (SACMNP-BT-HGAAS) method were ob- tained as 270.8 ng/L and 81.7 ng/L, respectively. The matrix-matching calibration method was performed in order to improve the accuracy of cadmium quantifica- tion in tap water and the recovery results obtained were as follows: 88.56 ± 8.92 and 97.43 ± 9.76, for 6.0 and 8.0 ng/mL of cadmium-spiked tap water samples, respectively. Keywords Cadmium . Magnetic nanoparticles . Stearic acid . Batch-type hydride generation atomic absorption spectrometry . Solid-phase microextraction Introduction Cadmium is known as toxic element due to its harmful effects on living organisms. It is carcinogenic (Nawrot et al. 2006) and has an inhibitory effect on vitamin D- stimulated Ca metabolism as well as Cu metabolism (Lane et al. 2015). Cadmium originates from deep ocean activities and volcanic eruptions as natural sources. It also originates from human-based activities including untreated drainage waters, heavy metal industry, and overconsumption of fossil fuels (Organization 2010). As a result of industrialization, environmental exposure to cadmium has increased especially in industrialized areas when compared with rural and urban environ- ments (Järup and Åkesson 2009). Although cadmium is almost harmless to organisms at ultratrace levels, serious adverse effects on human health could occur with increased release of cadmium into the environ- ment. Cadmium contamination in the soil and air could move up the food chain and enter the human body where it accumulates in organs and tissues. Besides that, tobacco consumption is another source for cadmium exposure due to inhalation of cigarette smoke. High Environ Monit Assess (2018) 190:589 https://doi.org/10.1007/s10661-018-6971-1 Highlights • A novel method was developed for the determination of Cd at ultratrace levels. • An enhancement factor of 514 produced a detection limit of 81.7 ng/L. • The method showed high precision. • Matrix matching was used to enhance analyte recovery from tap water medium. N. A. Kasa : E. Akkaya : B. T. Zaman : G. Çetin : S. Bakirdere (*) Department of Chemistry, Yildiz Technical University, 34349 Istanbul, Turkey e-mail: bsezgin23@yahoo.com