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In the present study we report the development of an advantageous optical sensor for the speciation of Fe(III)/Fe(II). The sensor is based on the selective reaction of Fe(III) with a Desferal (Deferoxamine) reagent at pH = 2, while both Fe(III) and Fe(II) react with the reagent at pH = 5 using an acetate/glycine buffer. In this way, frequently used extra oxidation (H2O2) or reduction (ascorbic acid or hydroxylamine) steps are avoided. Both species can be determined in the range of 25 to 150 μM using a 96-well plate platform and the instrument-free detection of the colored complex with an overhead book scanner. The LOD is 4 μM, and an additional advantage is that a single calibration curve can be utilized for quantitation. The applicability of the sensor was demonstrated by analyzing commercially available pharmaceutical formulations for quality control purposes.

Abstract Background Most older people, and especially those in need of long-term care, suffer from one or more chronic diseases. Consequently, older people have an increased need of medical care, including specialist care. There is little evidence as yet whether older people with greater medical care needs obtain adequate medical care because existing studies do not sufficiently control for differences in morbidity. In this study we investigate whether differences in medical specialist utilization exist between older people with and without assessed long-term care need in line with Book XI of the German Social Code, while at the same time controlling for individual differences in morbidity. Methods We used data from the 11 German AOK Statutory Health and Long-term Care Insurance funds of 100,000 members aged 60 years or over. Zero-inflated Poisson regression analyses were applied to investigate whether the need for long-term care and the long-term care setting are associated with the probability and number of specialist visits. We controlled for age, gender, morbidity and mortality, residential density, and general practitioner (GP) utilization. Results Older people in need of long-term care are more likely to have no specialist visit than people without the need for long-term care. This applies to nearly all medical specialties and for both care settings. Yet, despite these differences in utilization probability the number of specialist medical care visits between older people with and without the need for long-term care is similar. Conclusion Older people in need of long-term care might face access barriers to specialist care. Once a contact is established, however, utilization does not differ considerably between those who need long-term care and those who don’t; this indicates the importance of securing an initial contact.

Abstract Background Elderly in need of long-term care tend to have worse health and have higher need of medical care than elderly without need for long-term care. Yet, characteristics associated with long-term care need can impede health care access: Higher levels of long-term care need come with physical and cognitive decline such as frailty and memory loss. Yet, it has not been investigated whether level of long-term care need is related to medical care utilization. Methods We investigated the association between the level of long-term care and medical specialist utilization among nursing home residents and home care recipients. We applied zero-inflated Poisson regression with robust standard errors based on a sample of statutory health insurance members. The sample consisted of 100.000 elderly over age 60. We controlled for age, gender, morbidity and mortality, residential density, and general practitioner utilization. Results We found a strong gradient effect of the level of long-term care for 9 out of 12 medical specialties: A higher level of long-term care need was associated with a lower probability of having a medical specialist visit. Yet, we did not find clear effects of the level of long-term care need on the intensity of medical specialist care. These findings were similar for both the nursing home and home care setting. Conclusion The findings indicate that inequalities in medical specialist utilization exist between elderly with differing levels of long-term care need because differences in morbidity were controlled for. Elderly with higher need of long-term care might face more access barriers to specialist medical care.

In this communication, we describe the first analytical method for the determination of free histidine in hair care products (shampoos and conditioners). Cation-exchange chromatography combined with postcolumn derivatization and fluorimetric detection enabled the accurate (recovery: 83.5–114.8%) and precise (2.4–5.6% RSD) determination of free histidine without matrix interferences at concentration levels down to 1.5 mg kg−1. Real commercially available samples were found to contain the amino acid at levels ranging between 70 and 535 mg kg−1.

The determination of histamine in Greek foods that should potentially be avoided during a “low histamine diet” is reported herein. Cation exchange chromatography combined to selective post column derivatization proved to be an excellent tool for this type of analysis as well, offering accurate results following minimal sample preparation. Tomato-, eggplant- and spinach-related products have been successfully analyzed and were all found to contain histamine. Higher amounts were quantified in eggplants, eggplant salads and spinach in the range of 15.4–34.2 mg kg−1 and lower in fresh tomatoes and related products (0.8–10.6 mg kg−1). The method is capable of determining as low as 0.5 mg kg−1 histamine without matrix effects, with percent recoveries ranging between 87 and 112% (tomatoes and related products), 95 and 119% (eggplants and related products) and 90 and 106% (fresh and frozen spinach).

A novel, direct and simple colorimetric method employing μicroanalytical paper-based devices (μ-PADs) for the selective determination of bismuth is described. The suggested method exploits the colorimetric variation of bismuth after its rapid reaction with methyl thymol blue (MTB) in an acidic medium (pH ranging between 0.7 and 3.0), modified with nitric acid, on the surface of a paper device at room temperature. The devices are low cost, composed of chromatographic paper and wax barriers and the analytical protocol is easily applicable with minimal technical expertise and without the need for experimental apparatus. The user must add a test sample and read the color intensity of the colored Bi(III)–MTB complex formed at the sensing area using a simple imaging device such as a flatbed scanner. Various chemical variables, such as HNO3 and MTB concentration, reaction time, ionic strength, detection zone size and photo-capture detector are optimized. A study of interfering ions such as K+, Na+, Ca2+, Mg2+, Cl−, SO42− and HCO3− was also conducted. The stability of the paper devices is also studied in different maintenance conditions with particularly satisfactory results, rendering the method suitable for field analysis. The detection limits are as low as 3.0 mg L−1 with very satisfactory precision, ranging from 4.0% (intra-day) to 5.5% (inter-day). Natural water samples are successfully analyzed, and bismuth percentage recoveries were calculated in the range of 82.8 to 115.4%.

In this study, the development, validation, and application of a new liquid chromatography post-column derivatization method for the determination of Colistin in human urine samples is demonstrated. Separation of Colistin was performed using a core–shell C18 analytical column in an alkaline medium in order (i) to be compatible with the o-phthalaldehyde-based post-column derivatization reaction and (ii) to obtain better retention of the analyte. The Colistin derivative was detected spectrofluorometrically (λext/λem = 340/460 nm) after post-column derivatization with o-phthalaldehyde and N-acetyl cysteine. The post-column derivatization parameters were optimized using the Box–Behnken experimental design, and the method was validated using the total error concept. The β-expectation tolerance intervals did not exceed the acceptance criteria of ±15%, meaning that 95% of future results would be included in the defined bias limits. The limit of detection of the method was adequate corresponding to 100 nmol·L−1. The mean analytical bias (expressed as relative error) in the spiking levels was suitable, being in the range of −2.8 to +2.5% for both compounds with the percentage relative standard deviation lower than 3.4% in all cases. The proposed analytical method was satisfactorily applied to the analysis of the drug in human urine samples.

Herein, we report a new automated flow method based on zone fluidics for the simultaneous determination of homocysteine and homocysteine thiolactone using fluorimetric detection (λext = 370 nm/λem = 480 nm). Homocysteine thiolactone is hydrolyzed on-line in alkaline medium (1 mol L−1 NaOH) to yield homocysteine, followed by reaction with o-phthalaldehyde in a single step. Derivatization is rapid without the need of elevated temperatures and stopped-flow steps, while specificity is achieved through a unique reaction mechanism in the absence of nucleophilic compounds. Mixtures of the analytes can be analyzed quantitatively after specific separation with fluorosurfactant-capped gold nanoparticles that are selectively aggregated by homocysteine, leaving the thiolactone analogue in solution. As low as 100 nmol L−1 of the analyte(s) can be quantified in aqueous solutions, while concentrations > 2 μmol L−1 can be analyzed in artificial and real urine matrix following 20-fold dilution. The percent recoveries ranged between 87 and 119%.

In the present study we report the development of an advantageous optical sensor for the speciation of Fe(III)/Fe(II). The sensor is based on the selective reaction of Fe(III) with a Desferal (Deferoxamine) reagent at pH = 2, while both Fe(III) and Fe(II) react with the reagent at pH = 5 using an acetate/glycine buffer. In this way, frequently used extra oxidation (H2O2) or reduction (ascorbic acid or hydroxylamine) steps are avoided. Both species can be determined in the range of 25 to 150 μM using a 96-well plate platform and the instrument-free detection of the colored complex with an overhead book scanner. The LOD is 4 μM, and an additional advantage is that a single calibration curve can be utilized for quantitation. The applicability of the sensor was demonstrated by analyzing commercially available pharmaceutical formulations for quality control purposes. [ABSTRACT FROM AUTHOR]

IntroductionNursing home residents typically have greater needs for medical care than community-dwelling elderly. However, restricted cognitive abilities and limited mobility may impede their access to general practitioners and medical specialists. The provision of medical care in nursing homes may therefore be inappropriate in some areas of medical care. The purpose of this mixed-methods study is to systematically assess, evaluate and explain met and unmet medical care needs in German nursing homes and to develop solutions where medical care is found to be inappropriate.Methods and analysisFirst, statutory health insurance claims data are analysed to identify differences in the utilisation of medical care between nursing home residents and community-dwelling elderly with and without need for long-term care. Second, the health status and medical care of 500 nursing home residents are assessed and evaluated to quantify met and unmet medical care needs. Third, qualitative expert interviews and case conferences and, fourth, quantitative analyses of linked data are used to provide structural, case-specific and generalisable explanations of inappropriate medical care among nursing home residents. Fifth, a modified Delphi study is employed to develop pilot projects aiming to improve medical care in nursing homes.Ethics and disseminationThis study was approved by the Ethics Committee of the University of Bremen on 23 November 2017. Research findings are disseminated through presentations at national and international conferences and publications in peer-reviewed scientific journals.Trial registration numberDRKS00012383.

In the present study, the determination of histidine (HIS) by an on-line flow method based on the concept of zone fluidics is reported. HIS reacts fast with o-phthalaldehyde at a mildly basic medium (pH 7.5) and in the absence of additional nucleophilic compounds to yield a highly fluorescent derivative (λex/λem = 360/440 nm). The flow procedure was optimized and validated, paying special attention to its selectivity and sensitivity. The LOD was 31 nmol·L−1, while the within-day and day-to-day precisions were better than 1.0% and 5.0%, respectively (n = 6). Random urine samples from adult volunteers (n = 7) were successfully analyzed without matrix effect (−1 with percentage recoveries in the range of 87.6%–95.4%.

In the present study, we report the results of our investigation of the oxidative forced degradation of glutathione in its nutraceutical formulations by two validated analytical methods. The first is based on the reaction of glutathione with o-phthalaldehyde through an automated zone fluidics flow platform and fluorimetric detection (λex/λem = 340/425 nm). The second is based on the separation of glutathione and its oxidation product by a green reversed-phase HPLC method coupled to direct UV detection, at 210 nm. A solution of 3% w/v H2O2 provided fast oxidation of more than 95% of glutathione to yield oxidized glutathione in a time period of 180 min. The mechanism of the oxidation was proved to follow pseudo-first order kinetics. The k, t90 and t1/2 values were calculated.