Uv 1601 uv vis spectrophotometer

The thiobarbituric-acid reactive-substance colorimetric test was performed in a model system of Fe(II)-induced lipid peroxidation as an emulsion prepared from egg yolk phospholipids. Each sample contained 1 mg/mL of lecithin. LP was initiated using 0.1 mM FeCl₂. After 30 min incubation at 37 °C, 0.5 mL of 2.8% trichloroacetic acid solution and 0.5 mL of 0.5% thiobarbituric acid solution were added, following a second incubation at 100 °C for 20 min. Centrifugation at 3000 rpm for 20 min at 4 °C was performed, and we determined the absorbance value of the supernatant at 532 nm via Shimadzu UV-1601 UV-VIS spectrophotometer.

Starch content was analyzed using a UV1601 UV-Vis spectrophotometer (Shimadzu, Japan) at a wavelength of 600 nm, with a soluble starch standard (chromatographic grade, CAS: 140602; CNIFDC, China). The analytical chemicals, apparatus, analytical conditions, standard preparation, starch extraction, and preparation of C. wenyujin rhizomes samples have previously been described in detail by Zhang et al. [54 ].

The images of microbeads and AuNPs were obtained by using a Quanta 450 scanning electron microscope (SEM) and a Phillips CM200 transmission electron microscope (TEM). The UV–vis absorption spectra were recorded using a Shimadzu UV-1601 UV–vis spectrophotometer. A LabRAM Horiba Raman microscope equipped with LabSpec 6 software was used to measure the Raman spectra and image microbeads, SERS reporters, and immunocomplexes. A 785 nm Xtra II diode laser from Toptica was applied for Raman imaging, with the monochromator comprising 600 grooves per mm grating. The Raman spectra were recorded using an acquisition time of 5 s and an accumulation time of 3 s. The SWIFT mode in LabSpec 6 was used for Raman imaging with an acquisition time of 1 s and a step size of 0.1 micron. The peak and CLS mode in the Raman microscope were used to generate the Raman false-color images to establish selective binding in the immunoassays. The CLS fitting was used to set up and perform the multivariate classical least squares fitting procedure on single spectra and multidimensional spectral arrays using a set of reference component spectra. This method is a supervised multivariate decomposition technique [44 (link)].

Twenty milligrams of PuLG or FAPuLG was dissolved in 3 ml of DMSO. Five milligrams of DOX was separately dissolved in 1 ml of DMSO with trace amounts of TEA and added to the polymer/DMSO solution. The resulting solution was slowly added dropwise to 10 ml of deionized water for 10 min and then loaded into dialysis tubing. The tubing was put into 1 l of deionized water. During dialysis, DOX-loaded nanoparticles formed and organic solvent was removed. Dialysis was continued for 12 h with changes of the water every 2 h. The resulting solution was analyzed or lyophilized. To determine drug contents, 5 mg of lyophilized nanoparticles were dissolved in DMSO, and the absorbance was measured using a UV spectrophotometer (UV-1601 UV-VIS spectrophotometer, Shimadzu, Kyoto, Japan) at 479 nm. Drug contents (%, w/w) were calculated as (amount of DOX in the nanoparticles/weight of nanoparticles) × 100.

DOX (5~10 mg) was dissolved in 2 mL DMSO with a similar amount of TEA. ChitoHISss conjugates (40 mg) were dissolved in 5 mL DMSO/water mixture (4/1, v/v) and then mixed with DOX solution. This solution was magnetically stirred for 10 min and then dropped into 10 mL distilled water. The resulting solution was introduced into a dialysis membrane (MWCO: 2000 g/mol) and then dialyzed against 1 L water for 1 day. Water was exchanged in 2–3 h intervals for 24 h and then dialyzed solution was lyophilized or used for analysis.
To evaluate drug contents, the volume of dialyzed solution was adjusted to 40 mL using distilled water. After that, 5 mL of this solution was diluted with DMSO more than 10 times. The DOX concentration was measured at 479 nm with a UV spectrophotometer (UV-1601 UV-VIS spectrophotometer, Shimadzu, Kyoto, Japan). The drug content was calculated as follows: drug content (w/w) = (DOX weight in the nanoparticles/nanoparticle weight) × 100; loading efficiency (w/w) = (DOX weight in the nanoparticles/feeding weight of DOX) × 100.
Empty nanoparticles were prepared with the same procedure described above in the absence of DOX.

The polysaccharide content of rhizomes was determined in accordance with the methodology of the “Chinese Pharmacopoeia” (Appendix VA; 2015) [1 ]. The extracted polysaccharides were analyzed using a UV1601 UV-Vis spectrophotometer (Shimadzu, Japan) at a wavelength of 490 nm, with an appropriate amount of anhydrous glucose being used as the reference material (reference d-anhydroglucose; CAS: 0833–9501; CNIFDC, China). The analytical chemicals, apparatus, conditions, and preparation of standard and sample solutions have previously been described in detail by Chen [53 ].

The 1 mL cuvette for the control contained 1 mM xanthine, 20 µL xanthine oxidase (100 IU/L), and 0.04 mM NBT [43 (link),44 (link)]. In the sample compositions, the tested hydrazones at different concentrations were added. All measurement compositions were incubated at 37 °C, and the absorbance was determined spectrophotometrically at 560 nm via Shimadzu UV-1601 UV-vis spectrophotometer.