A quadruple mass Spectrometer was designed and fabricated and tested experimentally- This mass Spectrometer which is made for the first time in Iran, works only with electric field and does not need magnetic field. This mass Spectrometer is capable of separating molecules of mass between 2 and 70 mass units. The experimental results are repeatable. The sensitivity of the device is about 0.3 µ A/Torr in the pressure of 10-4 Torr and has the resolving power of 1.4 mass unit. This mass Spectrometer can be used to study the residual gas in a vacuum chamber in research works.

Two continuous-wave (cw) single mode diode-lasers (Toshiba TOLD 9150 and Sharp LT024MDO) are applied as pump and signal sources to obtain difference-frequency generation (DFG) in the mid-infrared (MIR) region by using an AgGaS2 crystal with a length of 30 mm for 90° type I phase-matching. Tunable MIR laser radiation around 5µm is obtained with an output power in the order of hundred nW while the diode lasers are operated at 20 and 30 n W around their center wavelengths 789 and 681 nun, respectively. To demonstrate the applicability of this MIR-DFG laser Spectrometer we recorded the absorption spectrum of CO for the P (21) rotational line at 2055.4 cm-1 in a 10 cm long cell and in the flame of a McKenna burner in order to estimate the self-broadening coefficient of CO, the collisional-broadening of CO with CO2, and the CO concentration distribution in the flame.

Introduction: Vibrio cholera is the primary culprit of the cholera epidemic, causing gastrointestinal diseases. Non-O1/O139 strains of V. cholera spread into food and drink, causing food poisoning. The present study aimed to investigate the identification ability of the VITEK Mass Spectrometer (VITEK MS) for V. cholera strains. Case Presentation: Firstly, we utilized VITEK MS and VITEK 2 Compact, in addition to the serum agglutination test and 16S rRNA gene sequencing, to identify two V. cholera strains. The VITEK MS was employed to identify two clinical strains of V. cholera, and their protein spectra were compared. The VITEK MS incorrectly identified one strain as Vibrio mimicus with a confidence level of 99. 9%,nevertheless, another strain was correctly identified as V. cholera with a confidence level of 99. 9%. VITEK 2 Compact identified both strains as V. cholera at a confidence level of 97. 0%. Serological tests revealed that the V. cholera strains were neither in the O1 nor O139 group. The 16S rRNA sequencing results confirmed the strains as V. cholera. The protein profiles of V. cholera and V. mimicus were observed to be similar, leading to the inability of the mass Spectrometer to distinguish between them. Conclusions: Vibrio mimicus and V. cholera both belong to the Vibrio genus. The VITEK MS cannot completely differentiate between V. cholera and V. mimicus. For accurate identification, it is recommended to use biochemical serological tests by VITEK 2 Compact or serum.