The amendment was passed in 1810. It needs 75 percent of the states to be ratified. There is no experation date on ratification. So far 12 states have ratified it (just 1 state short of the needed total to make it law at the time.)
Today however we have more states, therefore an additional 26 states would need to ratify it in order for it to become law.
The amendment reads:
"If any citizen of the United States shall accept, claim, receive or retain, any title of nobility or honour, or shall, without the consent of Congress, accept and retain any present, pension, office or emolument of any kind whatever, from any emperor, king, prince or foreign power, such person shall cease to be a citizen of the United States, and shall be incapable of holding any office of trust or profit under them, or either of them."
You know, when you think about it, everyone generalizes...