[Design and application of special solid phase extraction column for three cannabinol compounds in hemp].

Cannabidiol (CBD), cannabinol (CBN), and Δ9-tetrahydrocannabinol (THC) are the most important components of hemp, whose concentrations determine the properties and applications of hemp. Hemp contains a large number of impurities, which must be removed from the extracting solution before determining the cannabinol contents by ultra-high performance liquid chromatography (UHPLC). Neutral alumina, magnesium silicate, and graphitized carbon black have different surface characteristics when used as adsorbents. The removal rates of pigments, total sugar, total fatty acid glyceride, and metal ions as well as the recoveries of the three cannabinols in the extraction solution were evaluated. The amounts of neutral alumina, magnesium silicate, and graphitized carbon black were 1.80 g, 0.15 g, and 0.05 g, respectively. The three adsorbents were mixed well and packed into a polypropylene pipe to prepare a special 2 g/6 mL solid phase extraction (SPE) column for determining the three cannabinol compounds in hemp. The chemical components of the hemp flowers and leaves were extracted with an ethyl acetate/methanol (9∶1, v/v) mixture. After the extracting solution was allowed to pass through the SPE column, the recoveries of CBD, CBN, and Δ9-THC were 98.9%, 95.7%, and 99.2%, respectively. The removal rates of xanthophyll, chlorophyll a, and chlorophyll were 96.3%, 99.2%, and 95.5%, respectively. The removal rates of total sugar, total fatty glyceride, and metal ions were 98.5%, 96.9%, and 85.4%, respectively. In this study, the chromatographic conditions for analyzing the three cannabinol compounds were optimized. The cannabinol compounds were separated within 10 min on an Eclipse Plus C18 column (50 mm×2.1 mm, 1.8 µm) using a mobile phase consisting of 1% (v/v) acetic acid and acetonitrile (30∶70, v/v) at a flow rate of 0.5 mL/min. The detection wavelength was set at 210 nm with a diode array detector, and the sample injection volume was 1 µL. Good linear relationships were observed between the mass peak areas and mass concentrations of CBD, CBN, and Δ9-THC in the range of 0.5-50 mg/L. The corresponding correlation coefficients (R2) were 0.9983, 0.9995, and 0.9981, while the detection limits were 0.45 µg/L, 0.53 µg/L, and 0.38 µg/L. The recoveries of CBD, CBN, and Δ9-THC were 90.3%-96.9%, 93.7%-95.6%, and 90.8%-96.1%, with relative standard deviations (RSDs) of 2.2%-6.1%, 4.1%-8.0%, and 2.4%-4.8%, respectively. The results were satisfactory, demonstrating that the special SPE column made of neutral alumina, magnesium silicate, and graphitized carbon black was well suited for the determination of the three cannabinol compounds in hemp.

[Preparation of nickel-titanium alloy fiber/organosilicone-polyurethane solid phase microextraction head and its application to the determination of seven substituted benzenes in water].

Toluene-2,4-diisocyanate, polyester polyol, and hydroxy silicone oil were used as raw materials; stannous octoate was used as the catalyst; and cyclohexanone was used as the solvent to synthesize organosilicone-polyurethane (SP). The polymer was coated on the surface of a nickel-titanium alloy fiber treated hydrothermally with potassium hydroxide. It was the prepared for headspace solid phase microextraction (HS-SPME). The polymer structure was analyzed by infrared spectroscopy, the highest temperature of the coating was determined by thermogravimetric analysis, and the surface morphology of the extraction head was observed by scanning electron microscopy. The benzene series of toluene, xylene, m-dichlorobenzene, o-dichlorobenzene, ethyl benzoate, nitrobenzene and benzyl alcohol in water were determined by HS-SPME-gas chromatography (GC) method. There was a good linear relationship between the chromatographic peak area and mass concentration of each measured object. The correlation coefficients (R2) were 0.9926-0.9998. The limits of detection were 0.08-0.24 µg/L. The recoveries of the spiked samples were 95.9%-105.4%, and the relative standard deviations were 1.4%-5.0%. The coating of SPME head adhered more firmly, and had a better adsorption performance for the substituted benzenes in water.

[Determination of patulin in fruits and jam by solid phase extraction-ultra performance liquid chromatography].

With magnesium silicate, silica gel, diatomite and calcium sulfate as raw materials, a new solid phase extraction column was prepared through a series of processes of grinding to ethanol homogenate, drying and packing into polypropylene tube. The sample was hydrolyzed by pectinase, extracted by acetonitrile and purified by solid phase extraction. The target compounds were separated on a C18 column (100 mm×2.1 mm, 1.8 µm), using 0.8% (v/v) tetrahydrofuran solution as mobile phase with a flow rate of 0.5 mL/min. The detection wavelength was 276 nm. The effect of pectinase on extraction yield and purification effect of solid-phase extraction column were investigated. The optimum chromatographic conditions were selected. There was a good linear relationship between the peak heights and the mass concentrations of patulin in the range of 0.1 to 10 mg/L with the correlation coefficient (R2) of 1. The limit of detection for this method was 10.22 µg/kg. The spiked recoveries of samples were 86.58%-94.84% with the relative standard deviations (RSDs) of 1.45%-2.28%. The results indicated that the self-made solid phase extraction column had a good purification efficiency, and the UPLC had a high separation efficiency. The method is simple, accurate and of great significance for the quality and safety control of fruit products.

[Preparation and application of solid phase extraction packing of zirconia microsphere coated with sulfonated crosslinked polystyrene].

Zirconia microsphere was prepared by polymerization-induced colloid aggregation (PICA) method and carbon-carbon double bond was grafted onto its surface by titanic acid ester coupling reagent. Poly(styrene-divinylbenzene) was synthesized by free radical polymerization by using styrene, divinylbenzene and carbon-carbon double bond on the microsphere surface in solution system, so the polymer was coated on the microsphere surface. After the benzene ring of the polymer was sulfonated, the cation exchange packing for solid phase extraction (SPE) was obtained. The material was characterized by Fourier transform infrared spectroscopy, scanning electron microscope and X-ray energy dispersive spectroscopy. Three herbicides of mesotrione, atrazine and acetochlor in water were determined by the SPE cartridge coupled with high performance liquid chromatography (HPLC). In the range of 0.5 - 3.0 mg/L, the relationships between the peak areas and mass concentrations of mesotrione, atrazine and acetochlor were linear with the correlation coefficients of 0.9936, 0.9925, 0.9919, respectively. The limits of detection were 5.41, 6.72 and 13.4 microg/L for mesotrione, atrazine and acetochlor, respectively. The results showed that the zirconium dioxide microspheres coated with polymer have diameters in the range of about 6 to 8 microm, the SPE cartridges of which have high adsorption rate for the targets.

[Determination of dichloromethane and trichloromethane residues in ranitidine hydrochloride by headspace liquid phase microextraction coupled with gas chromatography].

A method for the determination of residual dichloromethane and trichloromethane in ranitidine hydrochloride by headspace liquid phase microextraction coupled with gas chromatography (GC) was developed. A homemade device was used to protect the organic drop. The effects of the nature of extraction solvent, extraction time, extraction temperature and microdrop volume on the extraction efficiency were investigated separately. The optimal experimental conditions were as follows: 2 microL of n-tridecane as extraction solvent, 30 min of extraction time, 60 degrees C of extraction temperature. The correlation coefficients of linear calibration curve were 0.9733 and 0.9724 within the concentration ranges of dichloromethane (1-10 microg/g) and trichloromethane (1-10 microg/g), respectively. The detection limits of dichlormethane and trichloromethane were 0.0273 microg/g and 0.0410 microg/g, respectively, the relative standard deviations were lower than 4.36% and 5.89%, and the recoveries of the method were 93.6%-102% and 98.1% respectively. The method is simple and reliable.

[Determination of citric acid mono polyethyleneoxide nonyl phenyl ether amber diehylene glycoldinitrate diglycollic amide by IR].

In the present paper, citric acid, acetic anhydride, polyethyleneoxide nonyl phenyl ether and diethanolamine were used as raw materials. The raw materials were purified, and the intermediate products were synthesized. Finally, the citric acid mono polyethyleneoxide nonyl phenyl ether amber diehylene glycol dinitrate diglycollic amide was made. The acidamide of the product synthesized was determined by IR. There is a characteristic peak of C=O in acidamide at 1 642.39 cm(-1). Using potassium rhodanate as a internal standard, and according to Lambert-Beer law, a method to determine the citric acid mono polyethyleneoxide nonyl phenyl ether amber diehylene glycol dinitrate diglycollic amide was developed. The linear regression equation is A = 0.007 6m+0.325 6 with a correlation coefficient (r2) of 0.998 9. The experimental results of the precisions and recoveries are satisfied. The method is very necessary for confirming the reaction extent and controlling quality of citric acid mono polyethyleneoxide nonyl phenyl ether amber diehylene glycol dinitrate diglycollic amide. So, the synthesis process conditions were right according to the IR data.

[Synthesis and characterization of citric acid mono-polyethyleneoxide nonyl phenyl ether amber diehylene glycoldinitrate diglycollic amide].

In the present paper, citric anhydride was made using citric acid. The citric acid mono-polyethyleneoxide nonyl phenyl ether was synthesized by using citric anhydride and polyethyleneoxide nonyl phenyl ether. Finally, the citric acid mono-polyethyleneoxide nonyl phenyl ether amber diehylene glycol dinitrate diglycollic amide was synthesized by using diethanolamine. The raw material, intermediate and product were characterized by IR. The two absorption peaks at 1866.90 cm(-1) and 1781.08 cm(-1) respectively are both strong, with the latter stronger than the former. It was indicated that citric acid had changed into citric anhydride. The absorption peak at 1736.14 cm(-1) is attributable to the stretching vibration of C==O in ester, and that at 1642.39 cm(-1) is attributable to the stretching vibration of C==O in acidamide. It was indicated that the product was citric acid mono-polyethyleneoxide nonyl phenyl ether amber diehylene glycol dinitrate diglycollic amide. So, the synthesis process conditions were right according to the IR data.

[Determination of the monomers in phenylethylene-butyl acrylate-vinyl triethoxy siloxane terpolymer for solid phase microextraction coating by combining IR and UV].

In the present paper, phenylethylene-butyl acrylate-vinyl triethoxy siloxane terpolymer, as SPME coating, was synthesized. Combining infrared spectrum and ultraviolet spectrum, the contents of the monomers were determined. The two monomers' mole ratio of phenylethylene to butyl acrylate was obtained by IR. The content of phenylethylene was obtained by UV. Then the contents of butyl acrylate and vinyl triethoxy siloxane were calculated from the phenylethylene quantity and the mole ratio. For the determination of the mole ratio of phenylethylene to butyl acrylate, the standard curve was A(r) = 0.114m(r) +/- 0.032 (A: absorptance ratio, m(r): mole ratio), and the correlation efficient(r2) was 0. 999 3; for the determination of the content of phenylethylene, the standard curve was deltaA = 0.078 6c + 0.081 2(deltaA: absorptance difference, c: concentration of phenylethylene), and the correlation efficient(r2) was 0.998 9. The relative standard deviation (RSD) for phenylethylene was 0.410%, and recoveries were 97.8%-104%. The relative standard deviation (RSD) for butyl acrylate was 0.39%, and the recoveries were 97.1%-99.6%.

[Determination of polyether silicon oil by IR].

In the present paper, with polyoxyethylene(10) octylphenol ether and hydrogenous silicon oil used as raw materials, and stannous octoate used as catalyst, polyoxyethylene(10) octylphenolether-hydrogenous silicon oil polymer was synthesized in toluene solvent. Residual hydrogenous silicon oil in the polymer was determined by IR. There is a characteristic peak at 2 167 cm(-1) for Si-H bond in hydrogenous silicon oil. Using span-60 as internal standard, depending Lambert-Beer law and some calculation process, the linear relation between the absorbance ratio(y) and the mass ratio(x) of sample was obtained. The linear regression equation is y=2. 07 2x+0.2963 with a correlation coefficient (r2) of 0.9989. The experimental results of the precisions and recoveries are satisfactory. An IR method to determine the content of hydrogenous silicon oil in polyether was established. The method is very necessary for confirming the reaction extent and controlling product quality and adjusting polyether silicon oil characters. The best process parameter was chosen in experiments. The polyether has good charactesistic for extracting alcohols and benzene homologues with bright future of application.

[Determining mole ratio of monomers in new adsorbent of solid-phase microextraction by infrared spectroscopy].

In the present paper, butyl acrylate and phenylethylene were used as monomers, benzoyl peroxide as evocator, n-butyl acetate and methylbenzene as solvent, a new type of solid-phase micro extraction adsorbent that is phenylethylene-butyl acrylate copolymer was synthesized by solution polymerization. The polymer has good behaviour for adsorbing arenas. According to Lambert-Beer law and some calculation process, the linear relation between the absorptance (y) of the two functional groups, which are benzene and ester, and the two monomers' mole ratio (x) was obtained. The absorptances were determined by IR. The standard curve was obtained by external standard method. The linear regression equation is y = 0.1362 + 0.0841x. The precisions and recoveries were investigated. RSD is 2.464%, and recoveries are 92.89%-103.94%. The results are satisfactory. This method is rapid and accurate.

[Determination of acetylene and vinyl chloride in hydrochloric acid from producing vinyl chloride by headspace gas chromatography].

A headspace gas chromatographic method was used for determining acetylene and vinyl chloride in hydrochloric acid from vinyl chloride production. Hydrogen chloride was neutralized by sodium hydroxide, so its effect on determining acetylene and vinyl chloride was eliminated. The headspace bottle was put in a water bath at 35 degrees C for 45 min. The GC column was a 2 m x 3 mm i.d. stainless steel tube packed with GDX-202 stationary phase. The column temperature was 140 degrees C. Injection volume was 1 mL. External standard method was used for quantitation. The relative standard deviation was 0.85% and the recoveries in the range of 30.0 micrograms/g-150 micrograms/g were 98.9%-103% for acetylene. The relative standard deviation was 1.4% and the recoveries in the range of 20.0 micrograms/g-100 micrograms/g were 98.8%-102% for vinyl chloride.