bids are invited for annual maintenance contract for gcms; shimadzu; six- monthly; yes; gc system checks: o inlet maintenance: replacing the septum, cleaning or replacing the inlet liner, and replacing critical seals. o column care: trimming the column and checking for contamination, or replacing the column if performance degrades beyond recovery. o gas supply: checking and replacing gas filters, such as carrier gas and split vent filters, as needed. o leak checks: using an electronic leak detector to test all fittings and connections. o autosampler: inspecting and cleaning the syringe, and checking the performance of the autosampler, including the valve components.  ms system checks: o source cleaning: removing and cleaning the ion source to remove contamination and restore sensitivity. o vacuum system: inspecting vacuum pumps and replacing the pump oil for the foreline pump. o tuning and calibration: running the auto-tune procedure to calibrate the mass spectrometer and verifying instrument performance with a test mix. o filament check: inspecting the filament and replacing it when aging.  software and system verification: o checking and, with customer approval, updating firmware and software. o saving instrument control settings and reviewing the instruments logbook.