📖 3 mins.

We have tested Sodium Dichloroacetate packages of four different suppliers for toxic substances and other impurities. Chemical analysis results conclude that the purest Sodium Dichloroacetate is DCA-LAB. Products with the highest amounts of impurities are PureDCA and PharmaDCA. PharmaDCA’s product has the highest amount of toxic substances.

OBJECT OF RESEARCH

Sodium Dichloroacetate samples of four different suppliers examined:

BrandCompanyProductLot/Batch numberExpiration date
DCA-LABCuraltus Ltd25 gr. DCA PowderLot No: D16-C1-2/25March, 2018
Sigma-AldrichSigma-Aldrich Chemie GmbH10 gr. DCA PowderLOT# STBD9074V
Pharma DCAA.W.P. Ltd20 gr. DCA PowderBatch No 01780November, 2017
Pure DCA / theDCAstore20 gr. DCA PowderLOT: 72641September, 2016

ANIONIC CHROMATOGRAPHY

Anionic dichloroacetate composition measured using Ionic chromatograph.

590 mg of DCA powder is dissolved in 1 lliter of distilled water (H2O conductivity – 5 mkS). Thus obtained solutions, each contained 590 mg/l sodium dichloroacetate, equivalent to 500 mg of dichloroacetate anion in 1 liter of water.

Prepared solutions (590 mg/l) examined using ionic chromatograph through an anionic column. The column and detector standardly calibrated for fluoride, chloride, nitrite, bromide, nitrate, phosphate, sulfate anions, additionally calibrated for dichloroacetate (Cl2CH-COO), monochloroacetate (ClCH2-COO), glyoxylate (OCH-COO) for anions and identification peaks determined other potential impurities: glycolate (HOCH2-COO), oxalate (OOC-COO) anions.

Results are presented in the table ranked from best to worst:

RankBrandDichloroacetae
concentracion, mg/l
Dichloroacetate
anion, mg/l
Monochloroacetate
anion, mg/l
Glyoxylate
anion, mg/l
Glycolate anionOxalate anionChloride anion
1DCA-LAB590500.930.09TracesTraces
2Sigma-Aldrich590501.090.35TracesTraces
3Pure DCA590446.850.360.21Visible peakVisible peakVisible peak
4Pharma DCA590484.261.40Visible peakVisible peak

Note: Chloride anion gives a peak of 0,45 µS with a standalone water sample, it is not assessed it quantitatively; it is certain that Sigma Aldrich and DCA-LAB products have an insignificant amount of chloride anion.

Anion chromatography charts of every product:
DCA-LAB
Sigma-Aldrich
Pure DCA
Pharma DCA

HEADSPACE GAS CHROMATOGRAPHY (HS-GC)

Volatile halogenated hydrocarbons (Determination of highly volatile halogenated hydrocarbon) of DCA solution measured with HS-GC chromatograph.

590 mg of DCA powder is dissolved in 1 lliter of distilled water (H2O conductivity – 5 mkS). 5 ml of the obtained solution is diluted  to 500 ml (100 times), resulting in solution that contains 5,9 mg/l of sodium dichloroacetate, which is equivalent to 5 mg dichloroacetate anions in 1 liter of water.

Prepared DCA solutions (5,9 mg/l) are examined via HS-GC method, heating the solution at  90 oC temperature. This method allows to precisely examine the amount of dissolved halogenated hydrocarbons in an aqueous solution: chloroform, bromdichlormetan, chlordibrommetan, bromoform, trichloreten, tetrachloreten, at a concentration between 0.1 μg/l and 2 μg /l.

The results are presented in the table ranked from best to worst:

RankBrandDichloroacetae
concentracion, mg/l
Chloroform, µg/lBromodichloromethane, µg/lChlorodibromomethane, µg/lBromoform, µg/lTrichloroethene, µg/lTetrachloroethene, µg/l
 Distilled water0<0.10<0.10<0.10<0.10<0.10<0.10
1DCA-LAB5,90.10<0.10<0.10<0.10<0.10<0.10
2Pure DCA5,90.13<0.10<0.10<0.10<0.10<0.10
3Sigma-Aldrich5,90.46<0.10<0.10<0.10<0.10<0.10
4Pharma DCA5,90.63<0.10<0.10<0.10<0.10<0.10

HS-GC charts of every product:
Pure water
DCA-LAB
Sigma-Aldrich
Pure DCA
Pharma DCA

SUMMARY

Summarized results of the Anionic chromatography and HS-GC (Headspace Gas chromatography) are presented in the table ranked from best to worst. Table columns show dichloroacetate amount (%) and amounts of measured impurities: toxic monochloroacetate (ppM), toxic chloroform (ppM) and other impurities (glycolate, glyoxilate, oxalate, chloride) and H2O amount (%). Visual evidence of mechanical impurities is assessed.

RankBrandDCA amount
advertised, %
DCA amount
determined, %
Monochlororacetate
anion amount, ppM
Chloroform
amount, ppM
Other impurities
+ H2O, %
Mechanical
impurities
1DCA-LAB9999,98153170,00Traces
2Sigma-Aldrich9899,93593780,00Traces
3Pure DCA9989,356102210.58Strongly noticealbe
4Pharma DCA9996,8323731072.92Strongly noticealbe

CONCLUSIONS

  1. Sodium Dichloroacetate from DCA-LAB and Sigma-Aldrich matches parameters advertised by the supplier.
  2. Sodium Dichloroacetate from PureDCA and PharmaDCA do not match advertised parameters.
  3. Purest Sodium Dichloroacetate is DCA-LAB.
  4. Sodium Dichloroacetate with most impurities is from PureDCA and PharmaDCA.
  5. Sodium Dichoroacetate from PharmaDCA has highest amounts of toxic substances.