What’s in my Gummies? Part 2

What’s in my Gummies? Part 2

Gummy Bears

Continuing on from last week with the gummy bear sample preparations, I decided to take a look at the different things in that gummy bear.  The gummy bear in question is a multivitamin that contains a multitude of different vitamins, so I decided to first focus on Vitamin C or Ascorbic Acid.  

Preparing the sample was quite easy, as I used the Lucidity SimplePREP system.  I used the gummy bear prep method from last week to do the sample prep for the sample agian this week.  The method used is as follows:

Lucidity SimplePREP Conditions
Temperature 37 ℃
Time 60 minutes
Volume 35 mL
Agitation  ON
Washes 3
Pretreat Volume 0 mL
Filtering OFF
Settling 0 minutes


Now, time to run the Ascorbic Acid standard to check the retention time.  The LC-UV method used for the Ascorbic Acid is as follows:


Lucidity LC-UV Method
  Flow Rate 0.6 mL/min
  Column C18 150 x 4.6 mm, 2.7 um
  Oven Temperature 30 ℃
  Wavelength 254 nm
  Flow Isocratic – 10 minutes
  Mobile Phase 1.58 g Sodium dihydrogen phosphate PH 3


Ascorbic Acid shows very well on the LC-UV detector and gives very nice sharp peaks.

25ug/mL Ascorbic Acid

Chromatogram of ascorbic acid at 25 ug/mL

I decided to make a standard curve using 2.5, 5 and 25 μg/mL giving an R² value of 0.9999.  That is a great calibration curve, so I went on to the next step.


standard curve

Calibration Curve for Vitamin C showing a good linear range and an R squared value of 0.9999

Moving on to the sample, I first calculated the dilution required to bring the sample into the range of the calibration curve using the labeled amount of Vitamin C as a guide.  Using the labeled amount of Vitamin C (15 mg), I determined that 100:1 dilution would bring my sample into the range of the calibration curve (between injection concentrations of 2.5 ug/mL and 25 ug/mL).

I then filtered and diluted the sample 100:1 in water and ran it in the Lucidity LC-UV.  The method produced a chromatogram with one peak, which it identified as Ascorbic Acid based on retention time and gave a concentration for Ascorbic Acid of 4.931 ug/mL based on the calibration curve associated with the method.

Gummy sample chromatogram

Chromatogram of the gummy sample diluted at 100 to 1

Taking into account the 100:1 dilution factor and the initial 35 mL of water that I added to the sample, the average amount per gummy for the samples is 15.4 mg.  The labeled amount is 15 mg, giving me a 103% recovery on the sample, which is reasonably accurate.

Next week I plan to investigate how much Thiamine is in this same gummy.  Stay tuned for these results.



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