American Citizen Applying for Work Visa at the Chinese Embassy in London

I am an American citizen, and I've accepted a job to teach in China starting August 2012. Before I leave to go teach, I would like to spend some time with my husband's family in the UK. I haven't gotten my visa yet, and my employer in China said that it will take another 3-4 weeks. I do not want to wait in the US that long; I want to go to England to see my in-laws. Will I run into trouble trying to get my work visa at the Chinese embassy in London as an American citizen? Any help is GREATLY appreciated!