Spq 9000

To determine the shoot B concentration, whole shoots were harvested after 20 days of hydroponic culture and then dried at 60°C for at least 3 days. After determination of total shoot dry weight, samples were acid-digested and subjected to inductively coupled plasma mass spectrometry (ICP-MS; SPQ-9000, Seiko Instruments Inc., Chiba, Japan) for quantifying the B concentration (Takano et al., 2002 (link)). Plants were also grown hydroponically until fruit ripening and harvest. After drying and acid digestion, B concentrations in the fruits were determined by ICP-MS.

The total concentrations of arsenic in the freshwater microalgae were determined by inductively coupled plasma mass spectrometry (ICP-MS, SPQ 9000, SEIKO, Japan). Filter paper containing microalgal cells was digested by a microwave digestion system (Multiwave 3000, Anton Paar) using the Sea 1-h method. After that, digested liquors were co-washed with 15 mL of ultrapure water and transferred to heat-resistant DigiTUBEs (DigiPREP Jr, SCP SCIENCE). Tubes were then heated on hot plates at 100 °C for 6–7 h. After evaporation, 2 mL of deionized water was added to the samples, and they were then subjected to ICP-MS for the quantification of the total arsenic content in their cells. The operational conditions of the ICP-MS were the following: a high-frequency output of 1.2 kW; plasma gas flow rate of 16 L min⁻¹; auxiliary gas flow rate of 1.0 L min⁻¹; nebulizer gas flow rate of 1.0 L min⁻¹; and sample replacement time of 10 s.
The mean values in different treatments were compared using Duncan’s multiple range test using the statistical program SPSS 22.0 for Windows (SPSS Inc., USA).