Combine pineapple juice, soy sauce, vinegar, oil, honey, pepper, paprika and garlic powder in small saucepan. Heat to boiling over medium-high heat, whisking occasionally. Reduce heat; simmer until slightly thickened. Remove from heat and reserve 1/3 cup glaze to serve as a sauce with the grilled fish.
Heat grill to medium heat and oil it with cooking spray. Place salmon on the grill and brush with glaze. Grill salmon until opaque and flaky, about 4 minutes on each side. Serve reserved glaze with salmon.