Polysorbate 80 solution— Dilute 100 mL of polysorbate 80 with alcohol to 1000 mL.

Assay preparation— Transfer 5 Capsules to a 100-mL volumetric flask. [note—For hard gelatin Capsules, accurately weigh not fewer than 20 Capsules. Using a sharp blade if necessary, carefully open the Capsules, without loss of shell material, and transfer the contents to a suitable container. Remove any contents adhering to the empty shells by washing with several portions of ether. Discard the washings, and allow the Capsule shells to dry. Weigh the empty Capsule shells, calculate the net weight of the Capsule contents, and transfer an accurately weighed portion of the Capsule contents, equivalent to about 5 Capsules, to a 100-mL volumetric flask.] Add about 15 mL of water, 10 mL of 6 N hydrochloric acid, and about 1 mL of Polysorbate 80 solution to the flask, and heat on a hot plate or steam bath, with intermittent swirling, until the Capsules are completely disintegrated or the contents are dissolved. Boil gently for an additional 15 minutes. Cool, dilute with water to volume, and filter, discarding the first 5 mL of the filtrate. Dilute this solution quantitatively, and stepwise if necessary, with 0.125 N hydrochloric acid to obtain a solution having a known concentration of about 2 µg of calcium per mL, adding 1 mL of Lanthanum chloride solution per 100 mL of the final volume.

Polysorbate 80 solution— Prepare as directed in the Assay for calcium.

Assay preparation— Proceed as directed for Assay preparation in the Assay for calcium, except to prepare the Assay preparation to contain about 1 µg of chromium per mL and to omit the use of the Lanthanum chloride solution.

Polysorbate 80 solution— Prepare as directed in the Assay for calcium.

Assay preparation— Proceed as directed for Assay preparation in the Assay for calcium, except to prepare the Assay preparation to contain about 2 µg of copper per mL and to omit the use of the Lanthanum chloride solution.

Assay preparation— Remove the contents of a counted number of Capsules by cutting open, using a sharp blade if necessary. Mix, and determine the weight of the contents. Transfer an accurately weighed quantity of the contents, equivalent to about 200 µg of fluoride, to a 100-mL volumetric flask. Add 10.0 mL of 1 N hydrochloric acid, 25.0 mL of 3 M Sodium acetate solution, and 25.0 mL of Sodium citrate solution, dilute with water to volume, and mix.

Assay preparation— Accurately weigh not fewer than 20 Capsules in a tared weighing bottle. Using a sharp blade if necessary, carefully open the Capsules, without loss of shell material, and transfer the contents to a 100-mL container. If necessary, remove any contents adhering to the empty shells by washing with several portions of ether. Discard the washings, and dry the Capsule shells with the aid of a current of dry air. Weigh the empty Capsule shells in the tared weighing bottle, and calculate the net weight of the Capsule contents. Transfer an accurately weighed portion of the Capsule contents, equivalent to about 1 mg of fluoride, to a 100-mL volumetric flask. Proceed as directed for Assay preparation in the Assay for fluoride, Method 2 under Oil- and Water-Soluble Vitamins with Minerals Tablets, beginning with “add 15 mL of water.”

Bromine water— To about 20 mL of bromine in a glass-stoppered bottle, add 100 mL of water. Insert the stopper into the bottle, and shake. Allow to stand for 30 minutes, and use the supernatant layer.

Procedure— Remove the contents of a counted number of Capsules by cutting open, using a sharp blade if necessary. Mix, and determine the weight of the contents. Transfer an accurately weighed quantity of the contents, equivalent to about 3 mg of iodine, to a nickel crucible. Proceed as directed in the Assay for iodide, Method 1 under Oil- and Water-Soluble Vitamins with Minerals Tablets, beginning with “Add about 5 g of sodium carbonate”.

Polysorbate 80 solution— Prepare as directed in the Assay for calcium.

Assay preparation— Proceed as directed for Assay preparation in the Assay for calcium, except to prepare the Assay preparation to contain about 5 µg of iron per mL and to omit the use of the Lanthanum chloride solution.

Polysorbate 80 solution— Prepare as directed in the Assay for calcium.

Assay preparation— Proceed as directed for Assay preparation in the Assay for calcium, except to prepare the Assay preparation to contain about 0.4 µg of magnesium per mL.

Polysorbate 80 solution— Prepare as directed in the Assay for calcium.

Assay preparation— Proceed as directed for Assay preparation in the Assay for calcium, except to prepare the Assay preparation to contain about 1 µg of manganese per mL and to omit the use of the Lanthanum chloride solution.

Polysorbate 80 solution— Prepare as directed in the Assay for calcium.

Assay preparation— Proceed as directed for Assay preparation in the Assay for calcium, except to take a number of Capsules or a portion of Capsule contents, equivalent to about 1000 µg of molybdenum, and to make appropriate dilutions to obtain a final concentration of about 10 µg of molybdenum per mL, omitting the addition of the Lanthanum chloride solution.

Procedure— Remove the contents of a counted number of Capsules by cutting open, using a sharp blade if necessary. Mix, and determine the weight of the contents. Transfer an accurately weighed quantity of the Capsule contents, equivalent to about 40 µg of molybdenum, to a 200-mL beaker, marked I. Proceed as directed for Procedure in the Assay for molybdenum, Method 2 under Oil- and Water-Soluble Vitamins with Minerals Tablets, beginning with “To another 200-mL beaker,” except to read Capsules in place of Tablets.

Assay preparation— Remove the contents of a counted number of Capsules by cutting open, using a sharp blade if necessary, mix, and determine the weight of the contents. Transfer an accurately weighed quantity of the contents, equivalent to about 100 mg of phosphorus, to a suitable flask. Proceed as directed for Assay preparation in the Assay for phosphorus under Oil- and Water-Soluble Vitamins with Minerals Tablets, beginning with “add 25 mL of nitric acid”.

Polysorbate 80 solution— Prepare as directed in the Assay for calcium.

Assay preparation— Proceed as directed for Assay preparation in the Assay for calcium, except to prepare the Assay preparation to contain 1 µg of potassium per mL and to omit the use of the Lanthanum chloride solution.

Assay preparation— Remove the contents of a counted number of Capsules by cutting open, using a sharp blade if necessary. Mix, and determine the weight of the contents. Transfer an accurately weighed portion of the Capsule contents, equivalent to about 1000 µg of selenium, to a suitable flask. Proceed as directed for Assay preparation in the Assay for selenium, Method 1 under Oil- and Water-Soluble Vitamins with Minerals Tablets, beginning with “and add about 12 mL of nitric acid.”

Assay preparation— Remove the contents of a counted number of Capsules by cutting open, using a sharp blade if necessary. Mix, and determine the weight of the contents. Transfer an accurately weighed portion of the contents, equivalent to about 20 µg of selenium, to a suitable flask. Proceed as directed for Assay preparation in the Assay for selenium, Method 2 under Oil- and Water-Soluble Vitamins with Minerals Tablets, beginning with “Add 10 mL of nitric acid.”

Polysorbate 80 solution— Prepare as directed in the Assay for calcium.

Assay preparation— Proceed as directed for Assay preparation in the Assay for calcium, except to prepare the Assay preparation to contain about 2 µg of zinc per mL and to omit the use of the Lanthanum chloride solution.