As40 autosampler

Bromide (C₀ = 100 mg/L $${\mathrm{Br}}^{-}$$ ) was revealed with a Dionex ICS-1000 IC ion chromatograph (Sunnyvale, CA, USA), with a conductivity cell detector equipped with a Dionex AS-40 Autosampler, a Dionex IonPac™ AG14 precolumn (4 × 50 mm), and a Dionex IonPac™ AS14 IC column with a 4 mm AESR 500 suppressor (Thermo Fisher Scientific, Chelmsford, MA, USA). The eluent phase was prepared with 3.5 mM Na₂CO₃ and 1.0 mM NaHCO₃, with 1.2 mL/min as the flow rate. On the other hand, for the test performed with NaCl (C₀ = 0.02 M), a HandyLab^® 330 conductometer (SI Analytics, Weilheim, Germany) was used to measure the conductivity variation. The data were processed by drawing the F curve (C/C₀) against time.

The mudstone encapsulated bone was processed inside a UV sterilized laminar flow hood. The fossil bone fragments and adjacent mudstone were carefully separated and bone surface was scraped off (hereafter referred to as scrapings) with a flame-sterilized autoclaved razor. The cleaned bone with outer surface removed, along with the scrapings and the surrounding mudstone matrix were powdered separately with sterilized mortars and pestles. To determine the water-extractable anions, 0.1 g of each powder fraction was thoroughly mixed with 1 mL Milli-Q H₂O and incubated overnight before measurement. The slurry was centrifuged at 14,000×g for 5 min and the supernatant was then filtered with 0.22 μm filter membrane for ion chromatography analyses. All samples (in triplicate) were analyzed on a Dionex chromatography system equipped with an IC25 Ion Chromatograph, AS40 autosampler, a LC25 chromatography oven and an EG40 eluent generator. Anions were separated using a Dionex IonPac AS15 (3 × 150 mm) analytical column connected to a Dionex IonPac AG15 (3 × 50 mm) guard column. The oven was maintained at 30 °C and the flow rate was set at 0.35 mL/min. The KOH gradient generated by the EG40 eluent generator was as follows: 0–10 min, 5 mM; 10–16 min, gradient from 5 to 40 mM; 16–30 min, isocratic at 40 mM; 30–33, 40 mM to 5 mM; and a final isocratic run (33–40 min) at 5 mM.

Ionic content was detected using a DIONEX-DX500 ion chromatograph equipped with an AS40 autosampler and ED40 electrochemical detector (Dionex Corporation, Sunnyvale, CA, USA) as described by Ariz et al. (2011) (link). Frozen plant tissue (200 mg) was incubated in 1 ml of milli-Q water for 5 min at 80 °C in a water bath. The soluble ionic fraction was obtained by centrifugation at 16 000 g for 30 min. The supernatants, stored at –20 °C, were diluted 1:10 for injection. Ion Pac CG12A and Ion Pac CG12A were used as the stationary phase and 30% 100 mM NaOH and 70% milli-Q water were used as the mobile phase at 1.5 ml min^–1 flow rate for 15 min. Soluble cations (Na⁺, K⁺, Mg²⁺, Ca²⁺, and NH₄⁺) were determined using 20 mM methanosulfonic acid as the mobile phase for 13 min.