Detailed, ready-to-use protocols for human biomonitoring methods, are provided here, which were developed to monitor concentrations of occupational toxicants, yet can be equally used for environmental monitoring. Examples are new methods for the determination of organophosphates or musk compounds in blood. All the methods are reliable, reproducible, adhere to "Good Laboratory Practice" standards and cover all the required steps from sampling to the interpretation of results with respect to relevant biological exposure values. This includes data on precision, accuracy, and detection limit, calibration procedures as well as potential sources of systematic errors.