Research Progress in Determination Methods of Formaldehyde Content in Indoor Air

The detection methods of formaldehyde content in indoor air, including traditional laboratory detection methods (AHMT spectrophotometry, phenol reagent spectrophotometry, acetyl acetone spectrophotometry and gas chromatography) and rapid detection methods (electrochemical sensor method, photoelectric spectrophotometry, etc.), were introduced and described. This paper systematically analyzes and compares the detection principle, applicable environment medium, detection flux and the advantages and disadvantages of each detection method. The future detection methods of formaldehyde content in indoor air were prospected.

DIFFERENCES VALUE OF PT AND APTT IN EXAMINATION OF ELECTROMECHANICAL AND PHOTO-OPTICAL METHOD

Background: Examination of PT and APTT in hospitals and clinical laboratories by utilizing the use of different instruments and methods. Examination of PT and APTT can be implemented through electromechanical or photo-optical techniques to detect changes in plasma turbidity. This method principle isprincipled that addition can affect the increase in plasma viscosity. Purpose: To analyze the differences in the values of PT and APTT between the electromechanical method and the photo-optical method. Method: Analytical observation, 32 plasma citrate without interference and hemolysis were examined at the Clinical Pathology Laboratory of RSU Haji Surabaya and the Ultra Medica Main Clinics Laboratory in Surabaya. The study used SPSS 24.0 program to determine whether there were PT and APTT values with an electromechanical and photo-optical method. Result: The result of PT and APTT with the electromechanical method was significantly higher than PT and APTT with the photo-optical method on samples without interference. In hemolytic samples, the result of PT with the electromechanical method was significantly higher than the PT result with the photo-optical method. Meanwhile, the result of APTT with the electromechanical method was significantly lower than the APTT result with the photo-optical method in hemolytic samples. Conclusion: There were significant differences in PT and APTT results between electromechanical and photo-optical in samples without interference and hemolytic. It is due to the difference in the detection principle between the two methods.

DISCREPANCY INR VALUE (INTERNATIONAL NORMALIZED RATIO) IN OPTICAL AND ELECTROMECHANICAL METHOD

Background: INR examination services at laboratories in hospitals and clinics use different methods and tools therefore, results of the INR examination are different. Purpose: To determine whether there are differences in the INR value between using the photo optic method and electromechanical method. Method: This study used a citrate blood sample with a ratio of blood and anticoagulant 9: 1 and used the Sysmex CA-600 device for the photo optic method and used the Thrombostat device for the electromechanical method. The sample consisted of 32 samples, namely 10 treatment samples to be analyzed and 22 normal samples. Using SPSS 25.0 to test data that was tested for normality test and in a different test. Result: The result of INR with the electromechanical method was significantly longer than INR with the photo optic method. In the hemolytic sample, the result was significantly higher than the INR result with normal samples. Conclusion: There are significant differences between results of the INR value using photo optic and electromechanical due to the difference in the detection principle between the two methods.

A Mobile Analytical Device for On-Site Quantitation of Anthocyanins in Fruit Beverages

Anthocyanins are antioxidant and anti-inflammatory ingredients in various fruit beverages, for which their conservation and quantitation are important for the food industry. In this paper, we report a simple, portable device for accurate on-site determination of total monomeric anthocyanins in fruit beverages employing a Wi-Fi scanner coupled with a flexible microchip and a free mobile app. The detection principle is based on the pH-induced colorimetric reactions of anthocyanins performed in a specially designed microchip and validated with standard spectrophotometric measurements. The microchip with multiple testing vials was prepared with the benchtop molding method with a common PDMS elastomer and a transparency film; the photo of the scanned microchip is wirelessly sent to a smartphone and the RGB values of individual reaction vials in the microchip are analyzed with a free mobile app to determine the corresponding concentrations. It was demonstrated that the quantitation performance of this POCT device is comparable with conventional spectrophotometry in the determination of total anthocyanins in both standard solutions and fruit beverages.

A Transit Time-Resolved Microflow Cytometry-Based Agglutination Immunoassay for On-Site C-Reactive Protein Detection

An accurate and rapid microflow cytometry-based agglutination immunoassay (MCIA) suitable for on-site antibody or antigen detection was proposed. In this study, quantitative C-reactive protein (CRP) detection was chosen as a model assay in order to demonstrate the detection principle. The average transit time was employed to estimate the extent of the agglutination reaction and improve the detection accuracy as compared to the intensity-dependent methods. The detection time was less than 8 min. and only a 20 µL serum sample was needed for each test. The results showed a linear relationship between the average transit time of aggregates and CRP concentrations ranging from 0 to 1 µg/mL. The R2 of this relationship was 0.99. The detection limit of this technology was 0.12 µg/mL CRP. The system used for CRP detection can be extended to also monitor other clinically relevant molecules.

A rapid and highly sensitive paper-based colorimetric device for the on-site screening of ammonia gas

A rapid and highly sensitive paper-based colorimetric sensor for the on-site detection of ammonia gas is presented in this study. The detection principle of this sensor is based upon a...