Hemoglobin is the main component of red blood cells and serves as the transporter for oxygen and carbon dioxide in the blood. Hemoglobin concentration (Hb) is usually reported as grams of hemoglobin per deciliter of blood (g/dL). Hb is commonly measured by the cyanhemoglobin (hemoglobin cyanide) method. A sample of blood is diluted in a solution of potassium ferricyanide and potassium cyanide, which oxidizes hemoglobin to hemiglobin (Hi; methemoglobin) and then converts it to hemoglobin cyanide (HiCN). The concentration of HiCN is then measured by spectrophotometry.
Method. Preheat oven to 200oC. Wipe roast with damp paper towels. Combine flour, mustard, salt and pepper in a small bowl and rub all over beef. Place the roast, fat side up in a roasting pan and roast, uncovered, for 30-40 minutes for a rare roast or 40-50 minutes for a medium roast.Once cooked, cover with foil and let stand for 15-20 minutes for easier carving. Reserve the cooking juices to make a gravy or jus, if desired.ombine flour, mustard, salt and pepper in a small bowl and rub all over beef. Place the roast, fat side up in a roasting pan and roast, uncovered, for 30-40 minutes for a rare roast or 40-50 minutes for a medium roast. Once cooked, cover with foil and let stand for 15-20 minutes for easier carving.
1 After 20 minutes turn the oven down to 325 degrees F. and roast until the desired internal temperature is reached (see guide below). 2  For medium-rare this will take approximately 15 minutes per pound. 3  Transfer to a large platter, and let the prime rib rest, loosely covered with foil for 30 minutes before serving. Rub the entire surface of the cold roast with butter, and coat evenly with the kosher salt and black pepper. 2  Leave the prime rib out at room temperature for 2 hours. 3  Preheat the oven to 450 degrees F. 4  When the oven is hot, put the roast in and cook for 20 minutes to sear the outside of the roast.