The aim of this work was to compare the performance of isotopeselective non-dispersive infrared spectrometry (IRIS) for the 13 C-urea breath test with the combination of the 14 C-urea breath test ( 14 C-UBT), urease test and histologic examination for the diagnosis of H. pylori (HP) infection. Fifty-three duodenal ulcer patients were studied. All patients were submitted to gastroscopy to detect HP by the urease test, histologic examination and 14 C-UBT. To be included in the study the results of the 3 tests had to be concordant. Within one month after admission to the study the patients were submitted to IRIS with breath samples collected before and 30 min after the ingestion of 75 mg 13 Curea dissolved in 200 ml of orange juice. The samples were mailed and analyzed 11.5 (4-21) days after collection. Data were analyzed statistically by the chi-square and Mann-Whitney test and by the Spearman correlation coefficient. Twenty-six patients were HP positive and 27 negative. There was 100% agreement between the IRIS results and the HP status determined by the other three methods. Using a cutoff value of delta-over-baseline (DOB) above 4.0 the IRIS showed a mean value of 19.38 (minimum = 4.2, maximum = 41.3, SD = 10.9) for HPpositive patients and a mean value of 0.88 (minimum = 0.10, maximum = 2.5, SD = 0.71) for negative patients. Using a cutoff value corresponding to 0.800% CO 2 /weight (kg), the 14 C-UBT showed a mean value of 2.78 (minimum = 0.89, maximum = 5.22, SD = 1.18) in HP-positive patients. HP-negative patients showed a mean value of 0.37 (minimum = 0.13, maximum = 0.77, SD = 0.17). IRIS is a lowcost, easy to manage, highly sensitive and specific test for H. pylori detection. Storing and mailing the samples did not interfere with the performance of the test.

A qualitative and quantitative analytical method was developed for the simultaneous determination of 24 illicit drugs and medicines, in preserved oral fluid samples collected with the StatSure Saliva Sampler collection device. The samples were prepared by liquid-liquid extraction followed by liquid chromatography/tandem mass spectrometry (LC/MS/MS) analysis. The chromatographic separation was performed with an Atlantis T3 (100 x 2.1 mm i.d., 3 microm) reversed-phase column using an acetonitrile/2 mM ammonium formate buffer pH 3.4 gradient and the MS/MS detection was achieved with two precursor-product ion transitions per substance. The method was fully validated, including specificity and capacity of identification, limit of detection (0.2-2.1 microg/L), limit of quantitation (0.8-6.4 microg/L), recovery (34-98%), carryover, linearity (the method was linear in the range 1-200 microg/L), intra-assay precision (coefficient of variance (CV) <20% for 20 microg/L and CV <10% for 100 microg/L) and inter-assay accuracy (mean relative error <15%) and precision (CV <20%). The method showed to be specific and sensitive. It has already been successfully used in four proficiency tests and subsequently applied to oral fluid samples collected from road traffic volunteers in the driving population of Portugal (districts of Lisbon, Coimbra and Porto), within the DRUID project.

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