Identification
A:
Add 2 to 3 drops of a solution of Maltose (1 in 20) to 5 mL of hot alkaline cupric tartrate TS. A red precipitate is formed.
B:
The retention time of the major peak in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation, as obtained in the Assay.
pH
791
Prepare a 1 in 10 solution in carbon dioxide-free water. For the anhydrous form, it is between 3.7 and 4.7; and for the monohydrate form, it is between 4.0 and 5.5.
Assay
Mobile phase
Use degassed water.
Resolution solution
Dissolve accurately weighed quantities of maltotriose, maltose, and glucose in water to obtain a solution having concentrations of about 10 mg of each per g.
Standard preparation
Dissolve an accurately weighed quantity of
USP Maltose Monohydrate RS in water to obtain a solution having a concentration of about 10 mg per g. Calculate the exact concentration on the anhydrous basis.
Assay preparation
Dissolve about 0.10 g of Maltose, accurately weighed, in water, and dilute with water to about 10 g. Accurately record the final solution weight, and mix thoroughly.
Chromatographic system (see Chromatography
621
)
The liquid chromatographic system is equipped with a refractive index detector maintained at a constant temperature of about 40
![](images/chars/deg.gif)
, and a 7.8-mm × 30-cm column that contains packing L58 (see
Chromatography
621![](images/chars/rang.gif)
). The column temperature is maintained at about 80
![](images/chars/deg.gif)
, controlled to within ±2
![](images/chars/deg.gif)
. Chromatograph the
Resolution solution, and record the peak responses as directed for
Procedure. Adjust the flow rate to about 0.35 mL per minute so that the resolution,
R, between maltotriose and maltose is not less than 1.6. Chromatograph the
Standard preparation, and record the peak responses as directed for
Procedure: the relative retention times are about 0.9 for maltotriose, 1.0 for maltose, and 1.2 for glucose; and the relative standard deviation for replicate injections is not more than 2.0%.
Procedure
Separately inject equal volumes (about 20 µL) of the
Standard preparation and the
Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the percentage of Maltose on the anhydrous basis, taken by the formula:
[10,000(CS / CU)(rU / rS)]/(100 W),
in which
CS is the concentration, in mg per g, on the anhydrous basis of
USP Maltose Monohydrate RS in the
Standard preparation; CU is the concentration, in mg per g, of Maltose in the
Assay preparation; rU and
rS are the peak responses obtained from the
Assay preparation and the
Standard preparation, respectively; and
W is the percentage obtained in the test for
Water.