Smartphone Apps for Food Purchase Choices: Scoping Review of Designs, Opportunities, and Challenges.

BACKGROUND: Smartphone apps can aid consumers in making healthier and more sustainable food purchases. However, there is still a limited understanding of the different app design approaches and their impact on food purchase choices. An overview of existing food purchase choice apps and an understanding of common challenges can help speed up effective future developments. OBJECTIVE: We examined the academic literature on food purchase choice apps and provided an overview of the design characteristics, opportunities, and challenges for effective implementation. Thus, we contribute to an understanding of how technologies can effectively improve food purchase choice behavior and provide recommendations for future design efforts. METHODS: Following the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews) guidelines, we considered peer-reviewed literature on food purchase choice apps within IEEE Xplore, PubMed, Scopus, and ScienceDirect. We inductively coded and summarized design characteristics. Opportunities and challenges were addressed from both quantitative and qualitative perspectives. From the quantitative perspective, we coded and summarized outcomes of comparative evaluation trials. From the qualitative perspective, we performed a qualitative content analysis of commonly discussed opportunities and challenges. RESULTS: We retrieved 55 articles, identified 46 unique apps, and grouped them into 5 distinct app types. Each app type supports a specific purchase choice stage and shares a common functional design. Most apps support the product selection stage (selection apps; 27/46, 59%), commonly by scanning the barcode and displaying a nutritional rating. In total, 73% (8/11) of the evaluation trials reported significant findings and indicated the potential of food purchase choice apps to support behavior change. However, relatively few evaluations covered the selection app type, and these studies showed mixed results. We found a common opportunity in apps contributing to learning (knowledge gain), whereas infrequent engagement presents a common challenge. The latter was associated with perceived burden of use, trust, and performance as well as with learning. In addition, there were technical challenges in establishing comprehensive product information databases or achieving performance accuracy with advanced identification methods such as image recognition. CONCLUSIONS: Our findings suggest that designs of food purchase choice apps do not encourage repeated use or long-term adoption, compromising the effectiveness of behavior change through nudging. However, we found that smartphone apps can enhance learning, which plays an important role in behavior change. Compared with nudging as a mechanism for behavior change, this mechanism is less dependent on continued use. We argue that designs that optimize for learning within each interaction have a better chance of achieving behavior change. This review concludes with design recommendations, suggesting that food purchase choice app designers anticipate the possibility of early abandonment as part of their design process and design apps that optimize the learning experience.

Trends in full-time working in general practice: repeated cross-sectional study.

BACKGROUND: There is little evidence and no agreement on what constitutes full-time working for general practitioners (GPs). This is essential for workforce planning, resource allocation and accurately describing GP activity. AIM: To clarify the definition of full-time working for general practitioners, how this has changed over time and whether these changes are explained by GP demographics. DESIGN AND SETTING: Repeated cross-sectional national surveys between 2010 and 2021. METHOD: Comparison of three measures of working time commitments (hours and sessions per week and hours per session) plus a measure of workload intensity across survey years. Multiple regression to adjust the changes over time for age, sex, ethnicity, contract type, area deprivation, and rurality. Unadjusted hours and sessions per week were compared to definitions of full-time working. RESULTS: Average hours and sessions per week reduced from 40.5 (95% CI: 38.5, 42.5) to 38.0 (36.3, 39.6) and 7.3 (7.2, 7.3) to 6.2 (6.2, 6.3) respectively between 2010 and 2021. In 2021, 54.6% of GPs worked at least 37.5 hours per week and 9.5% worked at least 9 sessions. Hours per session increased from 5.7 (5.7, 5.7) to 6.2 (6.2, 6.3) between 2010 and 2021. Partners worked more hours, sessions and hours per session. Adjustments increased the increase in hours per session from 0.54 to 0.61. CONCLUSION: At the current average duration of sessions, six sessions per week aligns with the NHS definition of full-time hours. However, hours per week is a more consistent way to define full-time work for GPs.

Exploring whether primary care networks can contribute to the national goal of reducing health inequalities: a mixed-methods study.

BACKGROUND: Significant health inequalities exist in England. Primary care networks (PCNs), comprised of GP practices, were introduced in England in 2019 with funding linked to membership. PCNs have been tasked with tackling health inequalities. AIM: To consider how the design and introduction of PCNs might influence their ability to tackle health inequalities. DESIGN AND SETTING: A sequential mixed-methods study of PCNs in England. METHOD: Linear regression of annual PCN-allocated funding per workload-weighted patient on income deprivation score from 2019-2023 was used. Qualitative interviews and observations of PCNs and PCN staff were undertaken across seven PCN sites in England (July 2020-March 2022). RESULTS: Across 1243 networks in 2019-2020, a 10% higher level of income deprivation resulted in £0.31 (95% confidence interval [CI] = £0.25 to £0.37), 4.50%, less funding per weighted patient. In 2022-2023, the same difference in deprivation resulted in £0.16 (95% CI = £0.11 to £0.21), 0.60%, more funding. Qualitative interviews highlighted that, although there were requirements for PCNs to tackle health inequalities, the policy design, and PCN internal relationships and maturity, shaped and sometimes restricted how PCNs approached this task locally. CONCLUSION: Allocated PCN funding has become more pro-poor over time, suggesting that the need to account for deprivation within funding models is understood by policymakers. The following additional approaches have been highlighted that could support PCNs to tackle inequalities: better management support; encouragement and support to redistribute funding internally to support practices serving more deprived populations; and greater specificity in service requirements.

How new clinical roles in primary care impact on equitable distribution of workforce: a retrospective study.

BACKGROUND: There are inequalities in the geographical distribution of the primary care workforce in England. Primary care networks (PCNs), and the associated Additional Roles Reimbursement Scheme (ARRS) funding, have stimulated employment of new healthcare roles. However, it is not clear whether this will impact inequalities. AIM: To examine whether the ARRS impacted inequality in the distribution of the primary care workforce. DESIGN AND SETTING: A retrospective before-and-after study of English PCNs in 2019 and 2022. METHOD: The study combined workforce, population, and deprivation data at network level for March 2019 and March 2022. The change was estimated between 2019 and 2022 in the slope index of inequality (SII) across deprivation of full-time equivalent (FTE) GPs (total doctors, qualified GPs, and doctors-in-training), nurses, direct patient care, administrative, ARRS and non- ARRS, and total staff per 10 000 patients. RESULTS: A total of 1255 networks were included. Nurses and qualified GPs decreased in number while all other staff roles increased, with ARRS staff having the greatest increase. There was a pro- rich change in the SII for administrative staff (-0.482, 95% confidence interval [CI] = -0.841 to -0.122, P<0.01) and a pro- poor change for doctors-in-training (0.161, 95% CI = 0.049 to 0.274, P<0.01). Changes in distribution of all other staff types were not statistically significant. CONCLUSION: Between 2019 and 2022 the distribution of administrative staff became less pro-poor, and doctors-in-training became pro-poor. The changes in inequality in all other staff groups were mixed. The introduction of PCNs has not substantially changed the longstanding inequalities in the geographical distribution of the primary care workforce.

Consequences of the closure of general practices: a retrospective cross-sectional study.

BACKGROUND: Two general practices close every week in the UK. Given the pressure on UK general practices, such closures are likely to persist. Yet little is known about the consequences. Closure refers to when a practice ceases to exist, merges, or is taken over. AIM: To explore whether practice funding, list size, workforce composition, and quality change in surviving practices when surrounding general practices close. DESIGN AND SETTING: A cross-sectional study of English general practices was undertaken, using data from 2016-2020. METHOD: The exposure to closure for all practices existing on 31 March 2020 was estimated. This is the estimation proportion of a practice's patient list that had been through a closure in the preceding 3 years, between 1 April 2016 and 3 March 2019. The interaction between the exposure to closure estimate and the outcome variables (list size, funding, workforce, and quality) was analysed through multiple linear regression, while controlling for confounders (age profile, deprivation, ethnic group, and rurality). RESULTS: A total of 694 (8.41%) practices closed. A 10% increase in exposure to closure resulted in 1925.6 (95% confidence interval [CI] = 1675.8 to 2175.4) more patients in the practice with £2.37 (95% CI = £4.22 to £0.51) less funding per patient. While numbers of all staff types increased, there were 86.9 (95% CI = 50.5 to 123.3), 4.3%, more patients per GP. Increases for other staff types were proportionate to increases in patients. Patient satisfaction with services declined across all domains. No significant difference in Quality and Outcomes Framework (QOF) scores was identified. CONCLUSION: Higher exposure to closure led to larger practice sizes in remaining practices. Closure of practices changes workforce composition and reduces patient satisfaction with services.

Improvements in anatomy knowledge when utilizing a novel cyclical "Observe-Reflect-Draw-Edit-Repeat" learning process.

Innovative educational strategies can provide variety and enhance student learning while addressing complex logistical and financial issues facing modern anatomy education. Observe-Reflect-Draw-Edit-Repeat (ORDER), a novel cyclical artistic process, has been designed based on cognitivist and constructivist learning theories, and on processes of critical observation, reflection and drawing in anatomy learning. ORDER was initially investigated in the context of a compulsory first year surface anatomy practical (ORDER-SAP) at a United Kingdom medical school in which a cross-over trial with pre-post anatomy knowledge testing was utilized and student perceptions were identified. Despite positive perceptions of ORDER-SAP, medical student (n = 154) pre-post knowledge test scores were significantly greater (P < 0.001) with standard anatomy learning methods (3.26, SD = ±2.25) than with ORDER-SAP (2.17, ±2.30). Based on these findings, ORDER was modified and evaluated in the context of an optional self-directed gross anatomy online interactive tutorial (ORDER-IT) for participating first year medical students (n = 55). Student performance was significantly greater (P < 0.001) with ORDER-IT (2.71 ± 2.17) when compared to a control tutorial (1.31 ± 2.03). Performances of students with visual and artistic preferences when using ORDER were not significantly different (P > 0.05) to those students without these characteristics. These findings will be of value to anatomy instructors seeking to engage students from diverse learning backgrounds in a research-led, innovative, time and cost-effective learning method, in the context of contrasting learning environments. Anat Sci Educ 10: 7-22. © 2016 American Association of Anatomists.

Twelve tips for implementing artistic learning approaches in anatomy education.

This article was migrated. The article was marked as recommended. To enhance learning and maximise student satisfaction while simultaneously optimising costs and resources within the modern context and environment of integrated anatomy education, it is vital that innovative methods of delivering learning and teaching are considered for implementation into medical curricula. The development of learning processes including observation, visualisation, haptic reasoning and visuospatial ability are strongly associated with the use of artistic approaches. In addition to being crucial for medical student learning of anatomy and other life sciences, such skills are also relevant for training in surgery, clinical observation and diagnosis. The twelve tips outlined here have been identified with the intention of providing guidance for anatomy educators aiming to incorporate innovative creative and artistic approaches into their own teaching practice within medical curricula. These proposals are underpinned by educational theory and recent research that has investigated artistic learning methods in medical education. Recommendations are also based on our personal experiences from both the undergraduate student point of view as well as the academic educator perspective with respect to the usage of creative and artistic learning approaches in anatomy education at Newcastle University.

Micellar electrokinetic chromatography of organic and peroxide-based explosives.

CE methods have been developed for the analysis of organic and peroxide-based explosives. These methods have been developed for deployment on portable, in-field instrumentation for rapid screening. Both classes of compounds are neutral and were separated using micellar electrokinetic chromatography (MEKC). The effects of sample composition, separation temperature, and background electrolyte composition were investigated. The optimised separation conditions (25 mM sodium tetraborate, 75 mM sodium dodecyl sulfate at 25°C, detection at 200 nm) were applied to the separation of 25 organic explosives in 17 min, with very high efficiency (typically greater than 300,000 plates m(-1)) and high sensitivity (LOD typically less than 0.5 mg L(-1); around 1-1.5 µM). A MEKC method was also developed for peroxide-based explosives (10 mM sodium tetraborate, 100 mM sodium dodecyl sulfate at 25°C, detection at 200 nm). UV detection provided LODs between 5.5 and 45.0 mg L(-1) (or 31.2-304 µM), which is comparable to results achieved using liquid chromatography. Importantly, no sample pre-treatment or post-column reaction was necessary and the peroxide-based explosives were not decomposed to hydrogen peroxide. Both MEKC methods have been applied to pre-blast analysis and for the detection of post-blast residues recovered from controlled, small scale detonations of organic and peroxide-based explosive devices.

Effects of eluent temperature and elution bandwidth on detection response for aerosol-based detectors.

Aerosol detectors provide generally uniform response for most analytes, independent of their optical properties, and have the advantage of being compatible with elevated temperature mobile phases. Therefore, aerosol detectors present an attractive detection alternative for high temperature liquid chromatography (HTLC) separations. The present study has investigated the effects of HTLC conditions using aqueous mobile phases on the detection response of an evaporative light-scattering detector (ELSD) and a corona-charged aerosol detector (C-CAD). The response of the ELSD was increased up to 5-fold by increasing the separation temperature from 30°C to 180°C. The C-CAD showed much smaller increases in response under the same conditions. This increase in response was found not to result from the increased temperature for the mobile phase but rather from compression of the elution bandwidth at elevated temperature. The effect of bandwidth on detector response was confirmed using flow-injection studies in which the same amount of analyte was introduced into the detector at varying bandwidths. Furthermore, it is shown that a temperature gradient can be used to counteract the effects of varying bandwidths associated with isocratic-isothermal separations, with relatively constant bandwidth and detector response being observed with appropriate temperature gradients. This study demonstrates the necessity to consider the elution bandwidth in HTLC-aerosol detector analysis.

On-line simultaneous and rapid separation of anions and cations from a single sample using dual-capillary sequential injection-capillary electrophoresis.

A novel capillary electrophoresis (CE) approach has been developed for the simultaneous rapid separation and identification of common environmental inorganic anions and cations from a single sample injection. The method utilised a sequential injection-capillary electrophoresis instrument (SI-CE) with capacitively-coupled contactless conductivity detection (C(4)D) constructed in-house from commercial-off-the-shelf components. Oppositely charged analytes from a single sample plug were simultaneously injected electrokinetically onto two separate capillaries for independent separation and detection. Injection was automated and may occur from a syringe or be directly coupled to an external source in a continuous manner. Software control enabled high sample throughput (17 runs per hour for the target analyte set) and the inclusion of an isolation valve allowed the separation capillaries to be flushed, increasing throughput by removing slow migrating species as well as improving repeatability. Various environmental and industrial samples (subjected only to filtering) were analysed in the laboratory with a 3 min analysis time which allowed the separation of 23 inorganic and small organic anions and cations. Finally, the system was applied to an extended automated analysis of Hobart Southern Water tap water for a period of 48 h. The overall repeatability of the migration times of a 14 analyte standard sample was less than 0.74% under laboratory conditions. LODs ranged from 5 to 61 µg L(-1). The combination of automation, high confidence of peak identification, and low limits of detection make this a useful system for the simultaneous identification of a range of common inorganic anions and cations for discrete or continuous monitoring applications.

Ion exchange chromatographic separation and isolation of oligosaccharides of intact low-molecular-weight heparin for the determination of their anticoagulant and anti-inflammatory properties.

It is well known that enoxaparin, a widely used anticoagulant and low-molecular-weight heparin containing a large number of oligosaccharides, possesses anti-inflammatory activity. Whilst enoxaparin has shown promising results in various inflammatory disorders, some of its oligosaccharides have anti-inflammatory properties and others increase the risk of bleeding due to their anticoagulant effects. The aim of this study was to develop an effective ion exchange chromatographic (IC) technique which allows the separation, isolation and, consequently, the identification of different oligosaccharides of enoxaparin with or without anticoagulant activity. The developed method utilises a semi-preparative CarboPac PA100 (9 × 250 mm) ion exchange column with sodium chloride gradient elution and UV detection at 232 nm. The method successfully resolved enoxaparin into more than 30 different peaks. IC-derived oligosaccharides with high, moderate, low or no anticoagulant activity were identified using an anti-factor Xa assay. The anti-inflammatory activity of selected oligosaccharides was investigated using the Griess assay. Using this technique, the oligosaccharides of enoxaparin with low or no anticoagulant activity, whilst exhibiting significant anti-inflammatory activity, could be fractionated. This technique can provide a platform to identify the oligosaccharides which are devoid of significant anticoagulant activity and are responsible for the therapeutic effects of enoxaparin that have been observed in various inflammatory conditions.

Investigation of polar organic solvents compatible with Corona Charged Aerosol Detection and their use for the determination of sugars by hydrophilic interaction liquid chromatography.

A range of organic solvents (ethanol, isopropanol and acetone) has been investigated as alternatives to acetonitrile and methanol when used in conjunction with Corona Charged Aerosol Detection (Corona CAD). These solvents have been evaluated with regard to their effect on the response of the Corona CAD. Three dimensional response surfaces were constructed using raw data showing the relationship between detector response, analyte concentration and percentage of organic solvent in the mobile phase, using sucralose or quinine as the test analyte. The detector response was non-linear in terms of analyte concentration for all solvents tested. However, detector response varied in an approximately linear manner with percentage of organic solvent over the range 0-40% for ethanol or isopropanol and 0-80% for acetone and methanol. The chromatographic performance of the various solvents when used as aqueous-organic mobile phases was evaluated for isocratic and gradient separations of sugars and sugar alcohols by hydrophilic interaction liquid chromatography (HILIC) using an Asahipak NH2P-504E column coupled with Corona CAD detection. It was found that whilst acetonitrile provided the highest column efficiencies and lowest detection limits of the solvents studied, acetone also performed well and could be used to resolve the same number of analytes as was possible with acetonitrile. Typical efficiencies and detection limits of 5330 plates m(-1) and 1.25 µg mL(-1), respectively, were achieved when acetone was used as the organic modifier. Acetone was utilised successfully as an organic modifier in the HILIC separation of carbohydrates in a beer sample and also for a partially digested dextran sample.

Determination of pharmaceutically related compounds by suppressed ion chromatography: IV. Interfacing ion chromatography with universal detectors.

This work forms the final part of a study investigating gradient elution ion-exchange chromatography of pharmaceutically relevant compounds, aiming at achieving complementary selectivity to reversed-phase HPLC. In this study the coupling of three universal detectors (electro-spray ionisation mass spectrometer (ESI-MS); corona charged aerosol detector (CAD); and evaporative light scattering detector (ELSD)) to suppressed IC using complex elution profiles with potassium hydroxide eluents is demonstrated. The non-volatile ions were removed from the eluent by the suppressor prior to detection, thus allowing a stable detector response, especially with the prototype electrolytic suppressor. The detector response for ten weakly anionic pharmaceuticals followed the expected models and the limits of detection obtained were not compromised by the use of a suppressor, yielding values below 50 ng/mL with MS, low to sub µg/mL levels with CAD and 2-20 µg/mL with ELSD (25 µL injections). When coupled to MS and CAD, the prototype electrolytic suppressor showed percentage relative standard deviations (%RSDs) in peak areas of 0.4-2.5% on average, compared to the chemical suppressor which yielded 1.5-3 fold higher %RSD values for the test analytes. The prototype electrolytic suppressor also generally exhibited wider linear response ranges than the chemical suppressor.

Comparison of the response of four aerosol detectors used with ultra high pressure liquid chromatography.

The responses of four different types of aerosol detectors have been evaluated and compared to establish their potential use as a universal detector in conjunction with ultra high pressure liquid chromatography (UHPLC). Two charged-aerosol detectors, namely Corona CAD and Corona Ultra, and also two different types of light-scattering detectors (an evaporative light scattering detector, and a nano-quantity analyte detector [NQAD]) were evaluated. The responses of these detectors were systematically investigated under changing experimental and instrumental parameters, such as the mobile phase flow-rate, analyte concentration, mobile phase composition, nebulizer temperature, evaporator temperature, evaporator gas flow-rate and instrumental signal filtering after detection. It was found that these parameters exerted non-linear effects on the responses of the aerosol detectors and must therefore be considered when designing analytical separation conditions, particularly when gradient elution is performed. Identical reversed-phase gradient separations were compared on all four aerosol detectors and further compared with UV detection at 200 nm. The aerosol detectors were able to detect all 11 analytes in a test set comprising species having a variety of physicochemical properties, whilst UV detection was applicable only to those analytes containing chromophores. The reproducibility of the detector response for 11 analytes over 10 consecutive separations was found to be approximately 5% for the charged-aerosol detectors and approximately 11% for the light-scattering detectors. The tested analytes included semi-volatile species which exhibited a more variable response on the aerosol detectors. Peak efficiencies were generally better on the aerosol detectors in comparison to UV detection and particularly so for the light-scattering detectors which exhibited efficiencies of around 110,000 plates per metre. Limits of detection were calculated using different mobile phase compositions and the NQAD detector was found to be the most sensitive (LOD of 10 ng/mL), followed by the Corona CAD (76 ng/mL), then UV detection at 200 nm (178 ng/mL) using an injection volume of 25 µL.

Glycan profiling of monoclonal antibodies using zwitterionic-type hydrophilic interaction chromatography coupled with electrospray ionization mass spectrometry detection.

We present a new method for the analysis of glycans enzymatically released from monoclonal antibodies (MAbs) employing a zwitterionic-type hydrophilic interaction chromatography (ZIC-HILIC) column coupled with electrospray ionization mass spectrometry (ESI-MS). Both native and reduced glycans were analyzed, and the developed procedure was compared with a standard HILIC procedure used in the pharmaceutical industry whereby fluorescent-labeled glycans are analyzed using a TSK Amide-80 column coupled with fluorescence detection. The separation of isobaric alditol oligosaccharides present in monoclonal antibodies and ribonuclease B is demonstrated, and ZIC-HILIC is shown to have good capability for structural recognition. Glycan profiles obtained with the ZIC-HILIC column and ESI-MS provided detailed information on MAb glycosylation, including identification of some less abundant glycan species, and are consistent with the profiles generated with the standard procedure. This new ZIC-HILIC method offers a simpler and faster approach for glycosylation analysis of therapeutic antibodies.

Universal response model for a corona charged aerosol detector.

The universality of the response of the Corona Charged Aerosol Detector (CoronaCAD) has been investigated under flow-injection and gradient HPLC elution conditions. A three-dimensional model was developed which relates the CoronaCAD response to analyte concentration and the mobile phase composition used. The model was developed using the response of four probe analytes which displayed non-volatile behavior in the CoronaCAD and were soluble over a broad range of mobile phase compositions. The analyte concentrations ranged from 1µg/mL to 1mg/mL, and injection volumes corresponded to on-column amounts of 25ng to 25µg. Mobile phases used in the model were composed of 0-80% acetonitrile, mixed with complementary proportions of aqueous formic acid (0.1%, pH 2.6). An analyte set of 23 compounds possessing a wide range of physicochemical properties was selected for the purpose of evaluating the model. The predicted response was compared to the actual analyte response displayed by the detector and the efficacy of the model under flow-injection and gradient HPLC elution conditions was determined. The average error of the four analytes used to develop the model was 9.2% (n=176), while the errors under flow-injection and gradient HPLC elution conditions for the evaluation set of analytes were found to be 12.5% and 12.8%, respectively. Some analytes were excluded from the evaluation set due to considerations of volatility (boiling point <400°C), charge and excessive retention on the column leading to elution outside the eluent range covered by the model. The two-part response model can be used to describe the relationship between response and analyte concentration and also to offer a correction for the non-linear detector response obtained with gradient HPLC for analytes which conform to the model, to provide insight into the factors affecting the CoronaCAD response for different analytes, and also as a means for accurately determining the concentration of unknown compounds when individual standards are not available for calibration.

Silica nanoparticle-templated methacrylic acid monoliths for in-line solid-phase extraction-capillary electrophoresis of basic analytes.

Polymeric ion-exchange monoliths typically exhibit low capacities due to the limited surface area on the globules of the monoliths. The ion-exchange binding of protonated weakly basic analytes on deprotonated carboxylate sites on methacrylate polymer monoliths has been increased by templating the monoliths with silica nanoparticles. The templating method is achieved by adding the nanoparticles as a suspension to the polymerisation mixture. After polymerisation, the nanoparticles are removed by washing the monolith with strong base. Monolithic columns prepared using this procedure have exhibited a 33-fold increase in ion-exchange capacity when compared to untemplated monoliths prepared and treated under similar conditions. The templating procedure does not alter the macroporous properties of the polymer monolith, confirmed through scanning electron microscopy and BET surface area analysis, but provides increased capacity predominantly through the re-orientation of more carboxylic acid groups. The resulting increase in ion-exchange capacity has proven to be useful for the preconcentration and separation of neurotransmitters by in-line solid-phase extraction-capillary electrophoresis. The increased capacity of the templated monolith allowed the injection time to be increased 10 times over that of an untemplated monolith, allowing 10 times more sample to be injected with the efficiencies and recoveries remaining unaffected. The enhancement in sensitivity for the test mixture of neurotransmitter (dopamine, norepinephrine and metanephrine) ranged 1500-1900 compared to a normal hydrodynamic injection in capillary electrophoresis. Efficiencies obtained for the neurotransmitters were 100000-260000 plates, typical of those obtained in capillary zone electrophoresis. The applicability of the increased capacity silica nano-templated polymer monolith was demonstrated by analysing trace levels of caffeine in biological, food and environmental samples.

Identification of inorganic ions in post-blast explosive residues using portable CE instrumentation and capacitively coupled contactless conductivity detection.

Novel CE methods have been developed on portable instrumentation adapted to accommodate a capacitively coupled contactless conductivity detector for the separation and sensitive detection of inorganic anions and cations in post-blast explosive residues from homemade inorganic explosive devices. The methods presented combine sensitivity and speed of analysis for the wide range of inorganic ions used in this study. Separate methods were employed for the separation of anions and cations. The anion separation method utilised a low conductivity 70 mM Tris/70 mM CHES aqueous electrolyte (pH 8.6) with a 90 cm capillary coated with hexadimethrine bromide to reverse the EOF. Fifteen anions could be baseline separated in 7 min with detection limits in the range 27-240 microg/L. A selection of ten anions deemed most important in this application could be separated in 45 s on a shorter capillary (30.6 cm) using the same electrolyte. The cation separation method was performed on a 73 cm length of fused-silica capillary using an electrolyte system composed of 10 mM histidine and 50 mM acetic acid, at pH 4.2. The addition of the complexants, 1 mM hydroxyisobutyric acid and 0.7 mM 18-crown-6 ether, enhanced selectivity and allowed the separation of eleven inorganic cations in under 7 min with detection limits in the range 31-240 microg/L. The developed methods were successfully field tested on post-blast residues obtained from the controlled detonation of homemade explosive devices. Results were verified using ion chromatographic analyses of the same samples.