Page 92 - Application Handbook - Liquid Chromatography
P. 92

LAAN-A-LC-E266







            Application                  High Performance Liquid Chromatography

            News                         Analysis of Mannitol Using RID-20A Differential


                                         Index Detector
            No.L489





            Mannitol possesses characteristics that include low
            moisture absorption and low reactivity, and is therefore
            used as an excipient for pharmaceuticals. USP methods
            for D-mannitol (hereafter, "mannitol") were amended
            in 2014 to specify the use of refractive index detection
            with a 7.8 mm × 300 mm L19 column.
            The RID-20A differential refractive index detector
            features an optical system with dual temperature
            control to absorb the impact of subtle changes in               Fig. 1 Structure of D-Mannitol
            temperature, thereby permitting chromatograms to be
            generated with a stable baseline. Here, we introduce an
            example of mannitol analysis using the RID-20A.

                                                                  uRIU
                                                                 20.0
                                                                 17.5                        ■ Peaks
            n System Suitability                                 15.0                  2        1. Isomalt (1)
                                                                 12.5                           2. Maltitol
            Fig. 1 shows the structural formula of mannitol. The   10.0                         3. Isomalt (2)
            test method for mannitol specifies that two types of   7.5               1  3       4. Mannitol
            system suitability test standard solutions be analyzed.   5.0                       5. Sorbitol
            The upper data of Fig. 2 shows the system suitability   2.5
            test results for Standard Solution 1, consisting of   0.0
            isomalt and maltitol standards (each 1 g/L), and the   0.0  2.5  5.0  7.5  10.0  12.5  15.0  17.5  20.0  22.5  25.0  27.5  min
                                                                  uRIU
            lower data of Fig. 2 shows the results using Standard   400
                                                                 350
            Solution 2, consisting of mannitol and sorbitol      300                          4
            standards (each 25 g/L). Table 1 shows the analytical   250                            5
            conditions.                                          200
            Table 2 shows the reference values for the system    150
            suitability test, in addition to the analysis results. The   100
                                                                 50
            results confirm that system suitability is satisfied with   0
            respect to all the criteria.                          0.0  2.5  5.0  7.5  10.0  12.5  15.0  17.5  20.0  22.5  25.0  27.5  min
                                                               Fig. 2  Chromatograms of a Standard Mixture of Four Sugar Alcohols
                         Table 1 Analytical Conditions
                                                                    Upper: System Suitability Solution 1 (Isomalt, Maltitol)
                                                                    Lower: System Suitability Solution 2 (Mannitol, Sorbitol)
                  System     : Prominence
                  Column     : Shim-pack SCR-101C
                               (300 mm L. × 7.9 mm I.D., 10 μm)
                  Mobile Phase   : Water
                  Flowrate   : 0.5 mL/min
                  Column Temp.   : 85 ˚C
                  Injection Volume : 20 μL
                  Detection   : RID-20A
                     Table 2 Results of System Suitability Test
              System Suitability   Target   Reference Value  Analysis
              Assessment Item  Substance            Result
                                      Approximately 20   20.9
              Retention Time  Mannitol
                                         minutes    minutes
                            Isomalt (1)  Approximately 0.6  0.68
             Relative Retention   Maltitol  Approximately 0.69  0.73
             Time with Respect
               to Mannitol  Isomalt (2)  Approximately 0.73  0.76
                             Sorbitol  Approximately 0.12  1.2
                           Mannitol and
                Resolution             Greater than 2.0  5.0
                             sorbitol
              Relative Standard
              Deviation of Peak   Mannitol  Less than 1.0 %  0.03 %
                Area Value
   87   88   89   90   91   92   93   94   95   96   97