In a saucepan, add chicken broth, lemon juice, garlic powder, black pepper, and white pepper. Mix well until the butter is completely melted.
Add salt and taste if more is needed. Remove the mixture from the heat and allow to cool until just warm for about 5- 10 minutes.
Fill the marinade into a meat injector and slowly inject it into the turkey in various spots. Fill the bird until the fluid starts oozing out. Massage all the injection sites to distribute the mixture throughout the bird.
Cover the turkey and let it rest in the fridge for several hours or overnight, if possible, before cooking. Turn on the oven to 325 F and roast the turkey for 15 to 20 minutes.
Check for the doneness of the turkey using a meat thermometer in the thickest part of the meat. The temperature should read a minimum of 165 F. Let the turkey rest for 30 minutes before carving.