What is a Hirsch funnel?

Hirsch funnels collect solids from a liquid sample. They resemble Büchner funnels because they use a perforated disk, but they have angled sides and hold a smaller quantity of fluid.

Hirsch funnels, combined with a side-arm flask and a vacuum aspirator, help chemists pull liquid through a perforated glass or porcelain plate, leaving the solid material behind. The difference with Hirsch funnels is the perforated plate is part of the funnel, unlike a removable disk that allows leakage around the edges. Some Hirsch funnels have fine glass filters, eliminating the need for filter papers. Most Hirsch funnels are used in organic chemistry laboratories.