An x-ray fluorescence apparatus for measuring properties of a sample fluid, the apparatus comprising a housing having an inlet and an outlet; a test chamber disposed within the housing, the test chamber comprising an injection port in fluid communication with the inlet; a slide disposed within the test chamber, the slide comprising a sample cavity; and a test port; an x-ray fluorescence spectrometer disposed within the housing, and at least one motor operatively coupled to the slide of the test chamber. Also, a method of testing a fluid, the method comprising injecting a fluid through an injection port of a test chamber into a sample cavity of a slide; moving the slide laterally within the test chamber to an intermediate position; moving the slide laterally within the test chamber to a test position; and actuating an x-ray fluorescence spectrometer to sample the fluid within the sample cavity when the slide is in the test position.