Lc 2030c plus

In the stress study of metronidazole in aqueous solutions and the vaginal lotion, as well as in further verification testing of its major photolytic degradant, the LC system (Shimadzu, Darul Khusus, Malaysia) consisted of a binary pump (LC-2030C plus), an autosampler (LC-2030C plus), a photo diode array (PDA) detector (LC-2030C plus) and a LC-2030C plus column oven. Data acquisition, analysis and reporting were performed using Shimadzu LC-Solution software. The starting chromatographic conditions chosen were based on available compendial monographs of metronidazole^{7 –11} . The Kromasil 100-5 C₁₈ column (250 mm × 4.6 mm i.d., 5 μm) (AkzoNobel, Bohus, Sweden) was maintained at 30 °C. Mobile phase A (0.05 mol/L KH₂PO₄ in water) and mobile phase B (methanol) were pumped at a total flow rate of 1.0 mL/min. The gradient program (time (min), % B) was set as: (0, 20), (12, 20), (30, 40), (40, 40), (45, 70), (50, 70), (51, 20), (60, 20). Sample solutions were 0.2 mg/mL of metronidazole in methanol–water (20:80, v/v) and the system suitability solution contained 1 μg/mL of metronidazole RS, 2-methyl-5-nitroimidazole RS and N-(2-hydroxyethyl)-5-methyl -l,2,4-oxadiazole-3-carboxamide RS, respectively. The injection volume was 10 μL and detection wavelengths were set at 315 nm and 230 nm simultaneously.

Ultrasound of P5091@RMPs‐R4F was performed in methanol solution following centrifugation (14 000 g, 10 min). Then, the supernatants were filtered (0.2 µm filters) for HPLC (LC‐2030C Plus, designed by Shimadzu Corporation in Japan). A C18 (250 × 4.6 mm, 5 µm particle size) HPLC packed column was used as the chromatographic column. The mobile phase was CH₃OH 0.5%TFA/H₂O 0.5% TFA (1:1, v/v), the flow rate was 1.0 mL min⁻¹, and the detection wavelength was 254 nm.

Glucose and lactate concentrations were determined by High-Performance Liquid Chromatography (HPLC). Samples are analyzed on a Shimadzu Prominence LC-2030C Plus with an RI detector (RID-20A). An isocratic method of 15 min on a Rezex ROA-Organic Acid H+ (8%) column (Phenomenex—part number 00F-0138-K0 + SecurityGuard Cartridge Kit (KJ0-4282) + SecurityGuard Cartridges Carbo-H 4 × 3.0 mm ID (AJ0-4490)) was used. The mobile phase was 5 mM sulfuric acid (Chem-lab CL00.2653.0050). The column temperature was 60°C and the temperature of samples was 4°C. The detection of glucose was done with an RI detector and the detection of lactate with a UV detector (210 nm).
Carboxylic acids (acetate, propionate, butyrate, iso-butyrate, valerate, iso-valerate, and caproate) were determined by gas chromatography (GC) with flame ionization detection (FID) as described by Candry et al. (2020) (link) after the extraction of acids into diethyl ether as described by Andersen et al. (2014) (link).
The gaseous head space composition was analyzed using a Compact Gas Chromatograph (Global Analyser Solutions, Breda, Netherlands), equipped with a Molsieve 5A pre-column and Porabond column (CH₄, O₂, H_2, and N₂), and a Rt-Q-bond pre-column and column (CO₂). Concentrations of gases were determined using a thermal conductivity detector.

The concentrations of DCF and IBP were measured using high-performance-liquid chromatography (HPLC; Shimadzu, LC-2030C plus) equipped with an ultraviolet detector and an analytical column: NUCLEODUR 100-5 C18 (250 mm × 4.6 mm, 5 μm pore size, Agilent). The injection volume was 10 μL and the flow rate was 1.0 mL min⁻¹. The eluent conditions were 40% 0.1 M sodium acetate and 60% methanol solution for DCF and 40% 0.1 M chloroacetic acid and 60% acetonitrile for IBP keeping for 30 min at 254 and 264 nm, respectively. Leached metal ions in the aqueous solution after treatment reaction was measured using inductively coupled plasm atomic emission spectroscopy (ICPE-9820, Shimadzu). Total organic carbon (TOC) removal was used to calculate the mineralization efficiency using a TOC-Analyzer (TOC-VCPH, Shimadzu).

High-performance liquid chromatography (HPLC, LC-2030C Plus, Shimadzu Corporation, Japan) was used to measure the content of LUT, SIT, MYA, and VAN in YFBP. A volume of 51.00 g of YFBP was accurately weighed and 100 ml of methanol was added, and the mixture was ultrasonicated for 12 h at 60°C. The extracts were filtered using a filter paper and concentrated to 1.00 g crude drug per ml. The concentrated solution was taken and passed through a 0.22-µm microporous membrane, and the content of LUT, SIT, MYA, or VAN was determined by HPLC. LUT, SIT, MYA, or VAN standards were accurately weighed and dissolved in methanol as the stock solution. Chromatography was performed on a C18 column (5 μm C18, 4.6 × 250 mm) at 35°C. LUT was eluted with a mobile phase (methanol/0.1% phosphoric acid water at a ratio of 50:50) at a flow rate of 0.5 ml/min and monitored at 350 nm. SIT was eluted with a mobile phase (methanol/water at a ratio of 55:45) at a flow rate of 0.5 ml/min and monitored at 210 nm. MYA was eluted with a mobile phase (acetonitrile/water at a ratio of 33:67) at a flow rate of 0.5 ml/min and monitored at 270 nm. VAN was eluted with a mobile phase (acetonitrile/0.1% phosphoric acid water at a ratio of 13:87) at a flow rate of 0.5 ml/min and monitored at 281 nm. The chromatograms were recorded and integrated using LabSolutions System software.

The neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) were determined using an ANKOM 2000 I, fiber Analyzer (ANKOM Technology Corporation, NY 14502, USA).
The dry matter content (TS) was analyzed with a moisture analyzer Ohaus MB 45. The volatile solids (VS) were analyzed as loss on ignition at 550 °C. The pH of the samples before and after pretreatment, hydrolysis, and fermentation was measured using a pH meter, model SevenCompact pH/Ion S220 from Mettler-Toledo AG (Schwerzenbach, Switzerland).
Glucose, glycerol, acetic acid, and ethanol were quantified by HPLC (LC-2030C Plus, Shimadzu, Kyoto, Japan) equipped with a refractive index detector (RID-20A, Shimadzu, Kyoto, Japan) using a Rezex ROA Organic Acid column (Phenomenex, Torrance, CA, USA) column at 45 °C, and isocratic elution at 0.6 mL/min of 5 mmol/L H₂SO₄.
The quantification of methane in the produced biogas was done by gas chromatography (CP-4900 Micro-GC, from Varian Inc., Palo Alto, USA).

The concentration of RSL3 in RMPs was measured by HPLC. HPLC analysis was conducted using a LC-2030C Plus instrument (Shimadzu, Japan). The separation was implemented with a ShimNex C18 chromatographic column (4.6 × 250 mm, 5 μm, 100 A, Shimadzu, Japan). Three times volume of acetonitrile was mixed with RMPs and then added chloroform (1:2, v/v). After vortexed, the mixture was centrifuged at 10,000 g for 5 min and the lower layer was extracted for measurement. As the standard solution, 10 mg RSL3 was dissolved in acetonitrile and chloroform in a ratio the same as RMPs. All the samples were filtered through a 0.45 μm polytetrafluoroethylene filter. The components were separated and eluted by mobile phase eluted (A: methanol; B: acetonitrile) in the column at 25 °C with a flow rate of 1 mL min⁻¹. An ultraviolet wavelength (254 nm) was selected for the detection of RSL3. For CT20p detection, FITC-CT20p was capsuled into RMPs by electroporation in different conditions and relative fluorescence units (RFU) was measured via SpectraMax^® iD3 microplate reader (MOLECULAR DEVICES, CA, USA).