ethylenediaminetetraacetic acid, pH 2.0); 5-min reaction time] ( Mehlich, 1984 ). At the end of extractions, the supernatant was filtered before being analyzed by the ICP (USEPA method 200.7). The plant samples were dried at 65 °C for 72 h and ground in a Wiley Mill to pass
, which can have secondary effects on potassium (K) uptake in plants. The objectives of this review are to 1) describe the impact of DL rate on substrate pH, 2) discuss the primary and secondary effects of DL on nutrient availability, and 3) summarize the
cool to room temperature, and the solution was filtered through wet filter paper and collected in a 50-mL volumetric flask. The residue was mixed with 20 mL of citrate buffer (pH 2.2) and the amino acid profile was determined using an automatic amino
, trachelium, and zinnia stems. Control solutions. Cut stems were held in DI water (pH 3.1–4.2; EC 0 dS·m −1 ), DI water supplemented with 200 mg·L −1 8-HQC (pH 2.8–3.1; EC 0.12–0.15 dS·m −1 ), tap water (pH 6.3–7.1; EC 0.18–0.23 dS·m −1 ), or tap water with 8
. The chromatographic column (3 μm, 150 × 3 mm) was an Acclaim 120 C18 (Dionex, Sunnyvale, CA), and the column temperature was 30 °C. Mobile phase A was acetonitrile, mobile phase B was water (adjusted to pH 2.6 with acetic acid), and the flow rate was 0
monobasic (KH 2 PO 4 , 0.5%, w/v) at pH 2.5 with metaphosphoric acid (HPO 3 , 0.1%, w/v). The retention time of the AA peak was 2.5 min. After comparison of retention time with the AA standard, the peak was identified. The amount of total AA content in
automated titrimeter and electrode standardized to pH 2.0, 4.0, 7.0, and 10.0 buffers. Titratable acidity was determined by titrating 0.1 N sodium hydroxide to 6 g of juice diluted with 50 mL of deionized, degassed water to an endpoint of pH 8.2, with
remaining pellet was again resuspended in 40 mL of HCl, pH 2.5, and incubated for 90 min at 60 °C. The extract was centrifuged and filtered to obtain the acid-soluble pectin (ASP). The remaining pellet was resuspended in 40 mL of 0.05 m NaOH and incubated
-H refill cartridge (30 × 4.5 mm) was used for a guard column. Columns were maintained at 65 °C by a temperature control unit. Mobile phase consisted of a pH 2.28 solution of sulfuric acid and water with a resistivity of 18 M obtained from a Millipore Milli
a BEH C18 column (Aquity, Waters Co). Each well was injected in triplicate with 5 μL of sample volume. The mobile phases consisted of 5 m m potassium phosphate monobasic (KH 2 PO 4 ), pH 2.65, with 0.1% of formic acid (mobile phase A) and methanol