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IntroductionAn issue of recent research interest is excessive stoma output and its relation to electrolyte abnormalities. Some studies have identified this as a precursor of dehydration and renal dysfunction. A prospective study was performed of the complications associated with high-output stomas, to identify their causes, consequences and management.Materials and methodsThis study was carried out by a multidisciplinary team of surgeons, gastroenterologists, nutritionists and hospital pharmacists. High-output stoma (HOS) was defined as output ≥1500 ml for two consecutive days. The subjects included in the study population, 43 patients with a new permanent or temporary stoma, were classified according to the time of HOS onset as early HOS (<3 weeks after initial surgery) or late HOS (≥3 weeks after surgery). Circumstances permitting, a specific protocol for response to HOS was applied. Each patient was followed up until the fourth month after surgery.ResultsEarly HOS was observed in 7 (16 %) of the sample population of 43 hospital patients, and late HOS, in 6 of the 37 (16 %) non-early HOS population. By type of stoma, nearly all HOS cases affected ileostomy, rather than colostomy, patients. The patients with early HOS remained in hospital for 18 days post surgery, significantly longer than those with no HOS (12 days). The protocol was applied to the majority of EHOS patients and achieved 100 % effectiveness. 50 % of readmissions were due to altered electrolyte balance. Hypomagnesaemia was observed in 33 % of the late HOS patients.ConclusionThe protocol developed at our hospital for the detection and management of HOS effectively addresses possible long-term complications arising from poor nutritional status and chronic electrolyte alteration.

The performance of the 1-ethyl-3-methylimidazolium dicyanamide ([emim][DCA]), 1-butyl-3-methylimidazolium dicyanamide ([bmim][DCA]), and 1-ethyl-3-methylimidazolium tricyanomethanide ([emim][TCM]) ionic liquids (ILs) as alternative solvents in the liquid–liquid extraction of toluene from heptane was evaluated at 313.2 K. These ILs were selected due to their low viscosity and their highly aromatic character. Densities and viscosities of the ILs have also been determined over the temperature range from 293.15 to 353.15 K. To analyze the potential of the ILs to be applied in an industrial aromatic extraction process, toluene and heptane distribution ratios, separation factors, and physical properties of the ILs have been compared to the sulfolane values. In addition, the nonrandom two-liquid model successfully correlated the liquid–liquid equilibrium data for the three ternary systems studied.

Online comprehensive two-dimensional liquid chromatography (LC × LC) offers ways to achieve high-performance separations in terms of peak capacity (exceeding 1000) and additional selectivity to realize applications that cannot be addressed with one-dimensional chromatography (1D-LC). However, the greater resolving power of LC × LC comes at the price of higher dilutions (thus, reduced sensitivity) and, often, long analysis times (>100 min). The need to preserve the separation attained in the first dimension (1D) causes greater dilution for LC × LC, in comparison with 1D-LC, and long analysis times to sample the 1D with an adequate number of second dimension separations. A way to significantly reduce these downsides is to introduce a concentration step between the two chromatographic dimensions. In this work we present a possible active-modulation approach to concentrate the fractions of 1D effluent. A typical LC × LC system is used with the addition of a dilution flow to decrease the strength of the 1D effluent and a modulation unit that uses trap columns. The potential of this approach is demonstrated for the separation of tristyrylphenol ethoxylate phosphate surfactants, using a combination of hydrophilic interaction and reversed-phase liquid chromatography. The modified LC × LC system enabled us to halve the analysis time necessary to obtain a similar degree of separation efficiency with respect to UHPLC based LC × LC and of 5 times with respect to HPLC instrumentation (40 compared with 80 and 200 min, respectively), while at the same time reducing dilution (DF of 142, 299, and 1529, respectively) and solvent consumption per analysis (78, 120, and 800 mL, respectively).

Nowadays, extraction of aromatics from aromatic/aliphatic mixtures is being investigated using cyano-based ionic liquids (ILs) as a new green alternative to currently used conventional organic extraction solvents, such as sulfolane. In this process, the maximum operation temperature (MOT) of the IL is a decisive property to know. Thus, thermal behavior of ILs is a target issue to study. The MOTs of cyano-based ILs 1-ethyl-3-methylimidazolium dicyanamide ([emim][DCA]), 1butyl-3-methylimidazolium dicyanamide ([bmim][DCA]), 1-ethyl-3-methylimidazolium thiocyanate ([emim][SCN]), 1-butyl-3-methylimidazolium thiocyanate ([bmim][SCN]), and 1-ethyl-3-methylimidazolium tricyanomethanide ([emim]-[TCM]) have been determined using dynamic and isothermal thermogravimetric analyses. In addition, specific heats from (296.2 to 372.2) K of all ILs included in this work have been also measured using differential scanning calorimetry (DSC). The MOT for [emim][TCM] was the highest, whereas the MOT for [emim][DCA], [bmim][DCA], and [bmim][SCN] were a little lower, the [emim][SCN] MOT being the lowest found. Specific heats of all ILs analyzed were higher than that of sulfolane.