▶ Sample：MSG(Monosodium L-glutamate ≥ 99%)；

Instrument: IP-digi2 digital polarimeter with thermostat system(Peltier)

▶ Room temperature: 22.0 ℃；

▶ Sample preparation:  weighing the sample 10.0g in a cleaned beaker, adding a small amount of DI water to dissolve it and transfer the solution to a 100 ml- volumetric flask. Adding 20 ml concentrated HCl to the flask slowly, mix it and waiting for the mixed solution cooling down to room temperature. Adding more DI water to the flask till the mark and mix them well follow the standard procedure.

▶ Specifics for the sample:

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 ▶ Measurement method: Specific Optical Rotation

       Temperature setting: 20.0℃, thermostat system is on.

       Thermostat sample tube length: L = 1 dm

       Sample concentration: C = 10 g/100ml

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 ▶ Sample solution is added into the thermostat sample tube and put it in the instrument sample chamber. Each sample takes 6 times readings. 

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 ▶ Test results:

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Purity of the MSG sample will be calculated by the following formula, in %.

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    X =           ×100

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    X  ——— content of the MSG in the sample，% ；

   [α]     ———  the reading of the sample’s Specific Optical Rotation ；

   25.16  ———the Specific Optical Rotation of the MSG

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Conclusion:

1)  The measurement results show that the purity of the MSG is above 99.0%, which meets the requirement of the Product purity.

2)  IP-digi2 gives out accuracy, stability, effective results which average error is within 0.3%.

3)  IP-digi2 is suitable for the MSG product quality inspection.

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