Printed on: Fri Jan 05 2024, 08:55:03 PM(EST) Status: Currently Official on 06-Jan-2024 DocId: GUID-3917EE95-A13E-42E7-9F25-FCC63DF6ED36_1_en-US
Printed by: USP NF Official Date: Official Prior to 2013 Document Type: DIETARY SUPPLEMENTS @2024 USPC
Do Not Distribute DOI Ref: 62y2r DOI: https://doi.org/10.31003/USPNF_M2764_01_01
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Cadmium standard solution: 1.0 µg/mL in 1% nitric acid,
Zinc Citrate prepared from a cadmium standard solution (10 mg/L)
Lead standard solution: 1.0 µg/mL in 1% nitric acid,
prepared from a lead standard solution (10 mg/L)
Multi-element standard solution: 10 µg/L of lead, 5 µg/L
of cadmium, and 3 µg/L of arsenic in 1% nitric acid,
prepared from the Lead standard solution, Cadmium
standard solution, and Arsenic standard solution, respectively
C12H10O14Zn3 · 2H2O 610.36 Sample solution: 2 mg/mL of Zinc Citrate in 1% nitric acid
2-Hydroxy-1,2,3-propanetricarboxylic acid zinc salt, dihydrat Instrumental conditions
e CAS RN®: 5990-32-9. (See Plasma Spectrochemistry á730ñ.)
Anhydrous CAS RN®: 546-46-3. Mode: ICP-MS
Radio frequency: 1350 Watts
DEFINITION Nebulizer flow rate: 0.9 L/min
Zinc Citrate contains NLT 31.3% of zinc (Zn), calculated on [NOTE—The radio frequency and nebulizer flow rate
the dried basis. settings may be developed and optimized based on the
IDENTIFICATION manufacturer’s recommendation.]
• A. IDENTIFICATION TESTS—GENERAL, Zinc á191ñ: A solution Detection atomic masses: As, Cd, and Pb
(1 in 10) meets the requirements. Blank: 1% nitric acid solution
• B. IDENTIFICATION TESTS—GENERAL, Citrate á191ñ: A Analysis
solution (1 in 10) meets the requirements. Samples: Multi-element standard solution, Sample
solution, and Blank
al
ASSAY Determine the responses of the Multi-element standard
• PROCEDURE solution, Sample solution, and Blank at the masses
Sample: 350 mg of Zinc Citrate, previously dried at 105° for indicated above.
2h Calculate the content of each element, in µg/g, in the
Blank: 60 mL of water portion of Zinc Citrate taken:
Titrimetric system
(See Titrimetry á541ñ.)
Mode: Direct titration
Titrant: 0.05 M edetate disodium VS
ci rU
Result = (rU/rS) × (CS/CU)
= peak response of the corresponding element
Endpoint detection: Visual from the Sample solution
Analysis: Dissolve the Sample in 60 mL of water. Add 10 mL rS = peak response of the corresponding element
ffi
of ammonia–ammonium chloride buffer TS and 0.1 mL of from the Multi-element standard solution
eriochrome black TS. Titrate with the Titrant to a blue CS = concentration of the corresponding element in
endpoint. Perform a blank determination. the Multi-element standard solution (µg/L)
Calculate the percentage of zinc (Zn) in the portion of Zinc CU = concentration of Zinc Citrate in the Sample
Citrate taken: solution (g/L)
O
Result = [(V − B) × M × F × 100]/W Acceptance criteria
Arsenic: NMT 3 µg/g
V = sample titrant volume (mL) Cadmium: NMT 5 µg/g
B = blank titrant volume (mL) Lead: NMT 10 µg/g
M = titrant molarity (mM/mL)
F = equivalency factor, 65.4 mg/mM SPECIFIC TESTS
W = sample weight (mg) • LOSS ON DRYING á731ñ: Dry a sample at 105° for 2 h: it loses
NMT 1.0% of its weight.
Acceptance criteria: NLT 31.3% on the dried basis • MICROBIAL ENUMERATION TESTS á2021ñ: The total aerobic
microbial count does not exceed 103 cfu/g. The total
IMPURITIES combined yeasts and molds count does not exceed 102 cfu/
• CHLORIDE AND SULFATE, Chloride á221ñ: A 1.0-g portion g.
shows no more chloride than corresponds to 0.7 mL of • MICROBIOLOGICAL PROCEDURES FOR ABSENCE OF SPECIFIED
0.020 N hydrochloric acid (NMT 0.05%). MICROORGANISMS á2022ñ: It meets the requirements of
• CHLORIDE AND SULFATE, Sulfate á221ñ: A 1.8-g portion the test for absence of Escherichia coli.
shows no more sulfate than corresponds to 0.5 mL of
0.020 N sulfuric acid (NMT 0.05%). ADDITIONAL REQUIREMENTS
• LIMIT OF ARSENIC, CADMIUM, AND LEAD • PACKAGING AND STORAGE: Preserve in well-closed
Arsenic standard solution: 1.0 µg/mL in 1% nitric acid, containers.
prepared from an arsenic standard solution (10 mg/L)
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