One difficult measurement to make in the domain of emissions control is that of fugitive volatile material, usually hydro carbonaceous, escaping from cooling tower water. Such measurements are necessary not only to allow plants to conform to laws limiting such emissions but also because sudden appearances of some materials in the cooling tower water are sometimes indicative of process leaks. The root of the analytical problem is that it is difficult to sample water in the field then to analyze it in the laboratory without some loss of the volatile material. Compounding the problem is the fact that the measurement of interest is the amount of material that volatilizes while the water is in the cooling tower. This measurement may not necessarily coincide with the total carbon in the water since some of it may be nonvolatile. Described herein is a sampling device, built specifically for use in the field, that can measure the volatile organic carbon content of cooling tower water.