AOAC SPIFAN ERP & Working Group Method Reviews (July 10, 2019)

First page Table of contents Previous page 36 Next page Last page

( f ) Mixed vitamin intermediate standard .—Pipet 1.0 mL vitamin A palmitate stock standard solution, 10.0 mL vitamin A acetate stock standard solution, and 25.0 mL vitamin E acetate stock standard solution into a 250 mL volumetric flask containing approximately 0.25 g coconut oil. Dissolve and dilute to volume with isooctane. Store frozen (<–20°C), protected from light. Expiration: 6 months. ( g ) α-Tocopherol intermediate standard .—Pipet 20.0 mL α-tocopherol stock standard solution into a 100 mL volumetric flask. Dilute to volume with isooctane. Store frozen (<–20°C), protected from light. Expiration: 6 months. ( h ) Mixed vitamin working standards .—Transfer about 20 mL mixed vitamin intermediate standard and 15 mL α-tocopherol intermediate standard into separate 25 mL volumetric flasks. Stopper and allow to come to room temperature. Store prepared working standards frozen (<–20°C), protected from light. Expiration: 2 months. ( 1 ) High working standard .—Pipet 10.0 mL of mixed vitamin intermediate standard and 5.0 mL α-tocopherol intermediate standard into a 50 mL volumetric flask containing about 0.50 g coconut oil. Dissolve and dilute to volume with isooctane. ( 2 ) Middle working standard.— Pipet 4.0 mL of mixed vitamin intermediate standard and 3.0 mL α-tocopherol intermediate standard into a 50 mL volumetric flask containing about 0.50 g coconut oil. Dissolve and dilute to volume with isooctane. ( 3 ) Low working standard.— Pipet 2.0 mL of mixed vitamin intermediate standard and 1.0 mL α-tocopherol intermediate standard into a 50 mL volumetric flask containing about 0.5 g coconut oil. Dissolve and dilute to volume with isooctane. ( 4 ) Very low working standard.— Pipet 1.0 mL of mixed vitamin intermediate standard and 0.5 mL α-tocopherol intermediate standard into a 100 mL volumetric flask containing about 1.0 g coconut oil. Dissolve and dilute to volume with isooctane. E. Preparation of Test Sample Infant, pediatric, and adult nutritionals .—Mix well to ensure that sample is homogeneous. Powdered products that are not

ƵƚŽƐĂŵƉůĞƌ͕ ϮϬ ђ> ŝŶũĞĐƚŝŽŶ

WƵŵƉ ϭ Ϭ͘ϯͲϬ͘ϴ ŵ>ͬŵŝŶ

ŽůƵŵŶ ϭ ^ŝůŝĐĂ͕ ϯ ђŵ͕ ϯ п ϯϬ ŵŵ

ŽůƵŵŶ Ϯ ^ŝůŝĐĂ͕ ϯ ђŵ͕ ϯ п ϮϬϬ ŵŵ

&ůƵŽƌĞƐĐĞŶĐĞ ĞƚĞĐƚŽƌ ǆ͗ Ϯϵϱ Ŷŵ͕ ŵ͗ ϯϯϬ Ŷŵ

WƵŵƉ Ϯ Ϭ͘ϲ ŵ>ͬŵŝŶ

hs ĞƚĞĐƚŽƌ sŝƚ͘ ͗ ϯϮϱ Ŷŵ sŝƚ͘ ͗ Ϯϴϱ Ŷŵ

direct and indirect white lighting, especially that from UV lights, sunlight, and fluorescent white lights. ( a ) Mobile phase.— 98.94% Isooctane, 1% dichloromethane, and 0.06% isopropanol. Pipet 20.0 mL dichloromethane and 1.2 mL isopropanol into a 2 L flask and dilute to volume with isooctane. Expiration: 2 days. ( b ) Vitamin A palmitate stock standard solution (approximately 2900 IU/mL) .—Accurately weigh an appropriate amount of vitamin A palmitate standard to give a stock standard concentration of approximately 2900 IU/mL (±10%) directly into a 100 mL volumetric flask. If using USP standard, weigh approximately 0.17000 g (±10%) of standard. Add approximately 0.10 g (±10%) of coconut oil (as a stabilizer/preservative for vitamin A). Dissolve and dilute to volume with isooctane. Store frozen (<–20°C), protected from light. Expiration: 6 months. ( c ) Vitamin A acetate stock standard solution (approximately 600 IU/mL) .—Accurately weigh an appropriate amount of vitamin A acetate standard to give a stock standard concentration of approximately 600 IU/mL directly into a 100 mL volumetric flask. If using USP standard, weigh approximately 0.72000 g (±10%) of vitamin A acetate dissolved in oil. Add about 0.10 g (±10%) of coconut oil (as a stabilizer/preservative for vitamin A). Dissolve and dilute to volume with isooctane. Store frozen (<–20°C), protected from light. Expiration: 6 months. ( d ) Vitamin E acetate stock standard solution (approximately 1 mg/mL) .—Accurately weigh an appropriate amount of vitamin E acetate standard to give a stock standard concentration of 1 mg/mL directly into a 100 mL volumetric flask. If using USP standard, weigh approximately 0.10000 g (±10%) of vitamin E acetate. Dissolve and dilute to volume with isooctane. Store frozen (< –20°C), protected from light. Expiration: 6 months. ( e ) α -Tocopherol stock standard solution (approximately 1 mg/mL) .—Accurately weigh an appropriate amount of α-tocopherol to give a concentration of 1 mg/mL directly into a 100 mL volumetric flask. If using USP standard, weigh approximately 0.10000 g (±10%) of α-tocopherol. Dilute to volume with isooctane. Store frozen (<–20°C), protected from light. Expiration: 6 months. Figure 2012.09A. System configuration 1: valve position at the beginning of an injection. Ex = excitation, Em = emission, and Vit. = vitamin.