Calcium citrate

Calcium citrate: mineral salt (calcium).

Calcium citrate testing at Vanguard Laboratory: identity, purity and quantity $250 per sample, with results in 3 to 5 business days.

Structure

Calcium citrate: 2D structure drawn from the PubChem record (CID 5282392).

Compound data

CAS number

5785-44-4

Formula

Ca₃(C₆H₅O₇)₂ · 4H₂O

Molecular weight

570.49 g/mol

Type

Mineral salt (calcium)

Structure and names

Identity: Calcium citrate tetrahydrate

IUPAC name: tricalcium;bis(2-hydroxypropane-1,2,3-tricarboxylate);tetrahydrate

How Vanguard tests Calcium citrate

Method for the $250 identity, purity and quantity test: ICP-MS metal content, HPLC assay of the citrate counter-ion, against a reference standard, with results in 3 to 5 business days.

The USP monographs cover identity by chemical tests and HPLC retention time, assay by ion chromatography (titration for calcium citrate malate), citrate, malate and fumarate content by HPLC, fluoride by ion chromatography or ion-selective electrode, arsenic and lead, acid-insoluble substances, pH, and loss on drying. Full testing to the USP Calcium Citrate monograph is available and quoted.

What's reported

Metal content by ICP-MS, against the label or specification
Purity, as percent of total peak area
Quantity, against the label claim
Identity, reported as match or no match against the reference standard
With monograph testing (quoted): the monograph’s tests against its limits

Tests and prices

Purity and quantity

$250

Chromatographic purity and mg per unit by the method matched to the compound, identity against a reference standard. 1 unit.

Raw powder purity

$200

Chromatographic purity on bulk powder. 50 mg.

Add-on tests

Add-on test	Price
Identity and impurities
FTIR identity	$90
CHNS elemental analysis (carbon, hydrogen, nitrogen, sulfur)	$125
Chiral purity (where a chiral method exists; new methods quoted)	$250
Water, solvents and salt form
Water content by Karl Fischer	$60
Residual solvents	$150
Counterions: chloride, acetate and TFA	$70
Assay
Assay, % w/w (with raw powder purity; $250 together)	+$50
Metals and conformity
Heavy metals: arsenic, cadmium, chromium, mercury and lead	$150
Conformity: purity and quantity on more units from the same lot	$100 per extra unit

10% off for 10 or more samples.

Need something else? Other tests are available on request.

Sample amount and turnaround

Purity and quantity is $250 per sample (1 unit) and raw powder purity is $200 for 50 mg, with results in 3 to 5 business days. Send the material sealed and labeled, with the label claim and the form it contains.

Salts, forms and compendial references

Calcium Citrate (CAS 5785-44-4, tetrahydrate)
Calcium Citrate Malate
Tell us the salt or form the label states, so quantity is reported on the same basis.

Questions about Calcium citrate testing

Is the $250 test the same as USP monograph testing?

No. The $250 test covers identity, purity and quantity by ICP-MS for calcium and HPLC for the citrate. Full testing to the USP Calcium Citrate monograph is available and quoted.

Is calcium citrate the same as calcium citrate malate?

No. Calcium citrate malate is a complex of calcium with both citrate and malate, so its calcium per gram and its organic acid profile differ from calcium citrate.

Is calcium reported as elemental calcium or as the salt?

Either. ICP-MS measures elemental calcium, which is what supplement labels usually state, and that can be converted to calcium citrate using the tetrahydrate molecular weight.

Sources

https://pubchem.ncbi.nlm.nih.gov/compound/5282392

Identity facts from the USP monograph header for this compound.

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