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The volatile fraction of urinary metabolites was investigated chromatographically at five different stages of the natural estrous cycle. A very substantial endocrine dependency has been noted for 11 compounds: 4 ketones, 2 acetate esters, 3 dihydrofuran isomers, dehydro-exo-brevicomin, and 2,5-dimethylpyrazine. The compounds were structurally verified through combined gas chromatography/mass spectrometry.

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Mouse urine samples from different pregnancy and lactation periods were examined by capillary gas chromatography to assess variations in the volatile signals that may affect the endocrine function of other females. Statistically significant changes in the excretion of certain urinary volatiles were observed; from 26 readily quantifiable constituents, 14 appear to be under the endocrine control. These selected components, positively identified through mass spectrometry and retention data, and the synthetic standards are ketones, unsaturated alcohols, esters, and cyclic vinyl ethers.

The volatile compounds identified by combined gas chromatography-mass spectrometry inMicrotus pinetorum urine include alcohols, aldehydes, hydrocarbons, ketones, nitriles, and pyrazines. Several lactone derivatives were found to be characteristic urinary substances of this species. Ovariectomy depressed concentrations of only five out of a great number of profile constituents. Elevating estrogen levels (by exposing females to male-soiled bedding or treating them with estradiol) tends to depress the urinary concentration of a number of selected volatiles. Estrogen implantation provoked a periodic increase in the level of three compounds (nonanal, benzal-dehyde, and an unidentified substance). The volatile profile of castrate male urine was similar to that of intact male urine. Female urine contained γ-octanoic lactone and two pyrazine derivatives in higher concentrations andp-methyI-propenylbenzene in a lower concentration, when compared to male urine. No qualitative differences between the urinary profiles of males and females were observed.

part of the solvent. This time, only the C22 peakwas reduced in size. Long venting times apparently not only leaked solvent onto the column during venting, but also led to loss of sample and to more discrimination than with short venting times.-. . ~ When the T-connector was replaced by a 3-way valve (Fig. 2), the solvent was not allowed to enter the column during venting. With theventing line closed throughout the run, the three first n-alkanes appeared as shoulders on the solvent peak (Fig. 6 A). With 30 s venting time the solvent was almost completely removed and the sample losses were not measureable (Fig. 6 B). The 0.2 1. 11 rotor in the injector was then replaced with a 0.5 1. 11 rotor. Injection of 0.5 1. 11 samples of n-alkanes in hexane solution, made by diluting the previoussample byafactorof 2.5, resulted in almost the same chromatograms, with equal peak heights (Fig. 7), compared to the more concentrated 0.2 1. 11 injections.Whether 0.5 pI injections represent a limit on 50 pm i.d. columns is not known, since higher volumes have not been tried yet.Less band broadening is expected when the venting valve can be replaced with a valve with smaller dead volumes. Further reduction in band-width can be obtained by using shorter columns and a mobile-phase velocity which is lower than the 7-8 cm/s used in this study. With the current system peaks with a signalhoise ratio of 10 were obtained by injecting 20 ppm solutions. With an optimized system, ppb concentrations are in the available range. AcknowledgmentFinancial support was received from STATOIL, Norway, through the Norwegian Academy of Sciences and from the Norwegian Council for Scientific and Industrial Research (NTNF). References

Urine samples from C3H congenic house mice (Mus domesticus) differing only at thet complex were examined by capillary gas chromatography to assess variations in the volatile components that may cause olfactory discrimination between animals bearingt lethal and+(wild-type) haplotypes. Urine was collected from 192 males and females varying in age from 1 to 9 months. C3H congenic mice that have the same genetic background at all loci but differed in theirt complex genotypes: +/ +, +/tw1,T/t w1, T/+ were used. No urinary volatiles were unique to thet complex. However, significant differences amongt complex genotypes and among ages occurred for concentrations of 12 male volatiles and four female volatiles. Usually young males (1-2 months of age) had significantly higher concentrations of cyclic enol ethers and ketones than older males (4-9 months of age). Moreover, some urinary volatiles (cyclic enol ethers, one ketone, dehydrobrevicomin, and thiazoline) were excreted in the urine of T/+and/orT/t males in significantly higher concentration than in the urine of +/+ males. Age andt complex genotype influences on the urinary volatiles in females were observed for four ketones. Gas chromatography of urinary components has the potential to be used in field studies of thet complex because the two t complex genotypes found in wild populations, +/+ and +/t, had significant differences in concentration for two males volatiles and three female volatiles.