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 . <EOS>