the solutions were measured by the colorimetric molybdenum blue method at 811 nm with a spectrophotometer (PGENERAL TU-1901 UV-VIS, Beijing, China). A control (no sample) was added to eliminate porcelain crucible errors.
the solutions were measured by the colorimetric molybdenum blue method at 811 nm witha spectrophotometer (PGENERAL TU-1901 UV-VIS, Beijing, China). A control (nosample) was added to eliminate porcelain crucible errors.