If you get gasoline on your clothing it is possible to remove the smell but it make take several steps. You should use some type of cloth immediately to remove as much of the gasoline as possible. You can then cover the area with baking soda which will absorb much of the remaining gas. Let this sit for a few minutes and then rub dishwashing liquid on the area and let it sit for about 30 minutes. You can then wash item by itself on the hot water cycle.
To get gasoline out of clothing let the clothes hang out in the sunshine to air out. White vinegar will help remove the smell. Add the vinegar to the wash cycle & wash. Other items you can try is Dawn dishwasher liquid rubbed in the area of the garment then washing. Baking soda also removes odors. Place the clothes in a bag then add some baking soda & leave in bag for a few days, wash as usual.