This disclosure relates to portable devices and methods for detecting, identifying and quantifying subcutaneously injected compounds in a subject. In an example, an injector is disposed in a housing, a cartridge is attached to the injector which includes the compound and one or more marker molecules, a near infrared radiation source is disposed in the housing, a monochromator is disposed in the housing through which the near infrared radiation is focused in a narrow bandwidth, a detector is disposed in the housing which includes detects near infrared radiation data absorbed by the marker molecule, a gyroscope identifies the angle of injection, a communication apparatus is disposed in the housing connected to the detector which electrically transmits the data collected by the detector and the gyroscope, and a battery is disposed in the housing connected to the communication apparatus, near infrared radiation source and the detector.
