Gas chromatographic determination of water in organic compounds and of organic compounds in water after steam distillation

A gas chromatograph (GC) with a flame ionization detector (FID) is shown to be effective in the determination of water in organic compounds. Since the FID gives little response for water, a reaction is needed to convert water into a detectable species. The ketal, 2,2-dimethoxypropane (DMP), reacts quantitatively with water to yield the products methanol and acetone when an acid catalyst is present. Acetone is easily determined with a GC equipped with a capillary column and FID. A solid acid catalyst, Nafion, has been effective and is easily separated before sample introduction into the GC;Several organic solvents were analyzed using this indirect method for determining water. The method is effective for determining water from 0.001-3.5% w/w. Larger concentrations of water can be determined by reducing the sample size. Solid samples were also analyzed and the water found in additional spikes agreed with the amount added;Simple steam distillation is used for the isolation and concentration of organic compounds from water matrices. Organic compounds are spiked into a flask containing water and the mixture is then boiled. Typical distillation times take less than 25 minutes. The condensate is collected in a small collection tube and a portion is injected into a GC containing a capillary column. The recovery of most compounds with boiling points from 77 to 238°C is better than 90% and a concentration effect of ten is realized. This method is very effective for phenols which traditionally have been difficult to distill;When compounds are present at concentrations in the part-per-billion range, a further concentration is necessary. Steam distillation combined with solid phase extraction is shown to be effective in isolating and concentrating compounds from water at these low concentrations. A simple interface between the boiling apparatus and resin collection column is presented. Once the organic analytes are boiled and collected on the resin, they are removed with a small amount of ethyl acetate. The ethyl acetate solution is then injected into a GC. Compounds with boiling points above 400°C can be determined by turning off the flow of cold water in the condenser. Recoveries are better than 80% for compounds with boiling points between 132 to 404°C. ftn*DOE Report IS-T 1396. This work was performed under Contract W-7405-Eng-82 with the Department of Energy

Long-Term Interaction: Learning the 4Rs

In long-term interaction (over minutes, hours, or days) the tight cycle of action and feedback is broken. People have to remember that they have to do things, that other people should do things and why things happen when they do. This paper describes some results of a study into long-term processes associated with the running of the HCI'95 conference. The focus is on the events which trigger the occurrence of activities. However, during the study we also discovered a recurrent pattern of activities and triggers we have called the 4Rs

Exploring Bluetooth based Mobile Phone Interaction with the Hermes Photo Display

One of the most promising possibilities for supporting user interaction with public displays is the use of personal mobile phones. Furthermore, by utilising Bluetooth users should have the capability to interact with displays without incurring personal financial connectivity costs. However, despite the relative maturity of Bluetooth as a standard and its widespread adoption in today’s mobile phones, little exploration seems to have taken place in this area - despite its apparent significant potential. This paper describe the findings of an exploratory study nvolving our Hermes Photo Display which has been extended to enable users with a suitable phone to both send and receive pictures over Bluetooth. We present both the technical challenges of working with Bluetooth and, through our user study, we present initial insights into general user acceptability issues and the potential for such a display to facilitate notions of community

Effectiveness of the ADEC as a level 2 screening test for young children with suspected autism spectrum disorders in a clinical setting

Background The Autism Detection in Early Childhood (ADEC) is a clinician-administered, Level 2 screening tool. A retrospective file audit was used to investigate its clinical effectiveness. Method Toddlers referred to an Australian child development service between 2008 and 2010 (N?=?53, M age?=?32.2 months) were screened with the ADEC. Their medical records were reviewed in 2013 when their mean age was 74.5 months, and the original ADEC screening results were compared with later diagnostic outcomes. Results The ADEC had good sensitivity (87.5%) and moderate specificity (62%). Three behaviours predicted autism spectrum disorders (ASDs): response to name, gaze switching, and gaze monitoring (p???.001). Conclusions The ADEC shows promise as a screening tool that can discriminate between young children with ASDs and those who have specific communication disorders or developmental delays that persist into middle childhood but who do not meet the criteria for ASDs