An apparatus comprising: a substrate; a gas chromatograph having a fluid inlet and a fluid outlet and being mounted to the substrate; a detector array having a fluid inlet and a fluid outlet and being mounted to the substrate, wherein the fluid inlet of the detector array is fluidly coupled to the fluid outlet of the gas chromatograph; a control circuit coupled to the gas chromatograph and to the detector array, wherein the control circuit can communicate with the gas chromatograph and to the detector array; a readout circuit coupled to the detector array and to the control circuit, wherein the readout circuit can communicate with the control circuit and the detector array; a pre-concentrator having a fluid inlet and a fluid outlet, wherein the pre-concentrator is mounted on the substrate and coupled to the control circuit, and wherein the fluid outlet of the pre-concentrator is coupled to the fluid inlet of the gas chromatograph; a filter and valve unit having a fluid inlet and a fluid outlet, wherein the filter and valve unit is mounted to the substrate and coupled to the control circuit, and wherein the fluid outlet of the filter and valve unit is coupled to the fluid inlet of the pre-concentrator; and a pump having a fluid inlet and a fluid outlet, wherein the pump is mounted on the substrate and coupled to the control circuit, and wherein the fluid inlet of the pump is coupled to the fluid outlet of the detector array, wherein the apparatus further comprising a shroud covering the filter and valve unit, the pre-concentrator, the gas chromatograph, the detector array and the pump, wherein the shroud provides the fluid connection among the filter and valve unit, the pre-concentrator, the gas chromatograph, the detector array and the pump. a substrate; a gas chromatograph having a fluid inlet and a fluid outlet and being mounted to the substrate; a detector array having a fluid inlet and a fluid outlet and being mounted to the substrate, wherein the fluid inlet of the detector array is fluidly coupled to the fluid outlet of the gas chromatograph; a control circuit coupled to the gas chromatograph and to the detector array, wherein the control circuit can communicate with the gas chromatograph and to the detector array; a readout circuit coupled to the detector array and to the control circuit, wherein the readout circuit can communicate with the control circuit and the detector array; a pre-concentrator having a fluid inlet and a fluid outlet, wherein the pre-concentrator is mounted on the substrate and coupled to the control circuit, and wherein the fluid outlet of the pre-concentrator is coupled to the fluid inlet of the gas chromatograph; a filter and valve unit having a fluid inlet and a fluid outlet, wherein the filter and valve unit is mounted to the substrate and coupled to the control circuit, and wherein the fluid outlet of the filter and valve unit is coupled to the fluid inlet of the pre-concentrator; and a pump having a fluid inlet and a fluid outlet, wherein the pump is mounted on the substrate and coupled to the control circuit, and wherein the fluid inlet of the pump is coupled to the fluid outlet of the detector array, wherein the apparatus further comprising a shroud covering the filter and valve unit, the pre-concentrator, the gas chromatograph, the detector array and the pump, wherein the shroud provides the fluid connection among the filter and valve unit, the pre-concentrator, the gas chromatograph, the detector array and the pump.