Can I apply for Chinese visa at Guangzhou Bai Yun airport?

I'm a USA citizen, now visiting in Guangzhou. My multi-entry one to China expires Sept 4, 2014. I inquired about extension of mine at the Guangzhou Entry & Exit Department, was told that I have to leave to a country, then reapply when I get back again. I'm leaving China for Africa next week for a short visit, not long enough to get to a Chinese Embassy or Consulate to apply. Can I apply at Guangzhou Bai Yun Airport when I return?