Page 6 - Shimadzu UV-1900i
P. 6

High Performance to Meet Diverse Needs



                                                                                                                                         Ultra-Fast Scan

                                                                                                                                         Spectra can be acquired as fast as 29,000 nm/min. Ultra-fast scan is effective in tracking chemical reactions in a short time. In
                                                                                                                                         addition to the absorbance change at specified wavelengths, spectra can also be acquired in a short time with the UV-1900i.
                                                                                                                                         Therefore, more detailed behavior can be investigated by observing spectra with the UV-1900i.
                                                                                                                                         The figures below show the analysis of the particle agglomeration process when salts are added to silver nanoparticles.
                                                                                                                                         Measurements of the 300 to 700 nm region were performed in ultra-fast scan mode. In addition to the decrease of
                                                                                                                                         absorbance at 400 nm and the increase of absorbance at 480 nm, the temporal changes of spectra can also be observed.

                                                                                                                                            1.0                                                        0.97                     0.23
                                                                                                                                                                                  Black: after 0 min
                                                                                                                                                                                  Red: after 0.5 min                            0.21
                                                                                                                                                                                  Blue: after 1 min
                                                                                                                                            0.8                                                        0.92            480nm
                                                                                                                                                                                  Green: after 2 min                            0.19
                                                                                                                                                                                  Orange: after 5 min
                                                                                                                                                                                  Purple: after 10 min  0.87
                                                                                                                                            0.6                                                                                 0.17
                                                                                                                                            Abs.                                                      Absorbance at 400 nm (Abs)  0.77  0.15 Absorbance at 480 nm (Abs)
                                                                                                                                            0.4                                                        0.72                     0.13
                                                                                                                                            0.2                                                                        400nm    0.11
                                                                                                                                                                                                       0.67
                                                                                                                                                                                                                                0.09
                                                                                                                                            0.0                                                        0.62                     0.07
                                                                                                                                             300.0        400.0       500.0        600.0        700.0   0   100  200  300  400  500  600
                                                                                                                                                                       nm                                         Time (sec)
                                                                                                                                                          Absorption Spectra of Silver Nanoparticles  Temporal Changes of Absorbance at 400 and 480 nm



























            Low Stray Light                                                                                                           High Reproducibility and Repeatability Accuracy
                                                                                     Abs.    Calibration Curve
            Stray light is at 0.5 % max. (198 nm), making accurate measurements are possible up to   3.00                             The photometric repeatability accuracy is 0.0002 Abs max. (0.5 Abs and 1.0 Abs). With this high photometric repeatability accuracy,
                                                                                          Instrument with 1.00 % Stray Light
            the vicinity of 2 Abs even in the ultraviolet region. In addition, high-concentration   2.50  UV-1900i                    variance in the measurement results is suppressed, enabling more accurate quantitation and the detection of low-concentration
            samples can be quantified accurately.                                 2.00                                                samples.
            The figure on the right is a calibration curve for acetic acid, created with absorbance at                                                                                                      2.5  Abs.  Calibration Curve
                                                                                  1.50
            200 nm.                                                                                                                   The figure on the right is a calibration curve for   No.  Absorbance of Blank Solution (273 nm)
                                                                                  1.00                                                caffeine, created with absorbance at 273 nm.  1        -0.00001       2.0
            The correlation coefficient is 0.9997 and correct measured values are obtained even in                                                                               2           0.00001
            the vicinity of 2 Abs. Linearity will be lost in the high absorbance region due to the   0.50                             The calibration curve has an Abs = 0.0528 Conc.   3    -0.00002       1.5
                                                                                                                                      The lower limit of quantitation determined from   4    0.00002
            stray light.                                                          0.00                                                                                           5           0.00001
                                                                                    0.00   1.00    2.00    3.00                       the standard deviation is 0.0051 mg/L.     6           -0.00003       1.0
                                                                                               Conc. (mg/L)
                                                                                                                                                                                 7           0.00001
                                                                                                                                                                                 8           -0.00004       0.5
                                                                                                                                                                                 9           0.00001
                                                                                                                                      Note: One method of determining the lower limit of   10  0.00005      0.0
                                                                                                                                      quantitation is to use ten times the standard deviation.   Standard  0.000025  0.0  10.0  20.0  30.0  40.0
                                                                                                                                      This is an actual measured value and is not guaranteed.  Deviation σ              Conc. (mg/mL)
                                                                                                                                                                                                                              UV-1900i
      6                                                                                                                                                                                                                       UV-VIS Spectrophotometer  7
   1   2   3   4   5   6   7   8   9   10   11