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Chinese Journal of Chromatography
2026, Vol. 44, No. 9
Online: 08 September 2026

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Research highlight in molecular imprinting recognition of phosphopeptide isomers CHEN Luxi, HU Lianghai 2026, 44 (9):  989-990.  DOI: 10.3724/SP.J.1123.2026.08007 Abstract ( 72 )   HTML ( 11 )   PDF (514KB) ( 23 )

Reviews

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Recent advances on environmental occurrence， risk and analytical methodologies of synthetic phenolic antioxidants LIU Sisi, LI Zijun, WEI Hongbo, XU Piaoli, LI Lina, CHEN Changer, YING Guangguo 2026, 44 (9):  991-1000.  DOI: 10.3724/SP.J.1123.2026.02013 Abstract ( 86 )   HTML ( 10 )   PDF (929KB) ( 20 )   Synthetic phenolic antioxidants （SPAs） are a major class of chemical additives extensively employed in plastics， rubber， and food packaging to prevent polymer degradation and extend product lifespans. In recent years， the environmental and human health risks of SPAs have received great concern due to their widespread occurrence in various environmental media. Existing reviews primarily focus on environmental detection， human exposure， toxicity， and risk assessment of SPAs with limited discussion on recent advances in analytical methodologies. This review presents a systematic synthesis of research advances over the past five years， especially the state of the art analytical methodologies. This review systematically analyzes their occurrence in water， sludge， sediments， soils， dust， and biota tissues， revealing a clear pollution transition from conventional SPAs to emerging high-molecular-weight substitutes. Toxicological evidence demonstrates that SPAs exert adverse effects on rats， mice， and aquatic organisms， including genotoxicity， immunotoxicity， endocrine disruption， reproductive toxicity， etc. Notably， certain transformation products （TPs） of butylated hydroxytoluene （BHT） exhibit enhanced toxicity relative to their parent compounds. Methodological advances in sample preparation and analysis techniques of SPAs in different environmental matrices are reviewed for the first time. Recent applications of atmospheric pressure chemical ionization coupled with liquid chromatography-tandem mass spectrometry （APCI-LC-MS/MS）， as well as high-resolution mass spectrometry （HRMS） provide powerful approaches for target/non-target analysis of unknown SPA derivatives and TPs. Several critical research gaps have finally been identified. Environmental analytical methods of SPAs and their TPs face significant challenges due to their diverse physicochemical properties and chemical reactivity， particularly their susceptibility to oxidation. Another key issue is that current pretreatment approaches for SPAs in tissue samples overlook bound-SPAs， thereby underestimating their real body burdens. Moreover， existing studies mainly focus on traditional SPAs， while lacking systematic assessment of environmental fate and long-term ecological risks posed by emerging SPAs and potentially more toxic TPs. Additionally， ecotoxicological data of SPAs for terrestrial organisms are scarce compared to aquatic organisms and mammals， limiting comprehensive ecological risk assessment. Future research should prioritize： （1） developing oxidant-resistant pretreatment methodologies coupled with HRMS to overcome technical challenges in accurate quantification of trace SPAs and their bound species； （2） strengthening non-target screening and identification of emerging SPAs and TPs； （3） investigating long-term effects of SPAs in soil-plant-microorganism systems. This review advances our understanding of SPAs by bridging the knowledge gaps and providing updated insights into current research. It will help establish the scientific basis for comprehensive ecological risk assessment of SPAs.

Articles

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Comparison of chiral separation performance of （2-hydroxyethyl-β）-cyclodextrin bonded superficially porous and fully porous particle chiral stationary phases in supercritical fluid chromatography and reversed-phase liquid chromatography YANG Guangyong, WU Haijiang, ZHANG Huangtao, WANG Hongli, LIANG Qiuyan 2026, 44 (9):  1001-1009.  DOI: 10.3724/SP.J.1123.2025.12017 Abstract ( 190 )   HTML ( 16 )   PDF (1255KB) ( 25 )   Chromatography remains a cornerstone technique in analyzing chiral compounds. The development and selection of chiral stationary phases （CSPs） are central to achieving high-resolution enantiomeric separation. This study presents a novel regeneration and functionalization strategy for the preparation of high-performance superficially porous particle （SPP）-CSP， offering a promising alternative to conventional fully porous particle （FPP）-CSP. First， bonded phases on the surface of spent chromatographic column silica packing materials were removed using ultraviolet light （λ=254 nm） and hydrogen peroxide solution （3%， mass fraction）， thereby obtaining sub-3 μm regenerated SPP. The regenerated SPP were then amino-functionalized. Subsequently， under mild reaction conditions， carbonyldiimidazole-activated （2-hydroxyethyl）-β-cyclodextrin （HE-β-CD） was bonded onto the surface of the amino-functionalized SPP to prepare the SPP-CSP. For comparative evaluation， a CSP based on 3 μm commercial FPPs was prepared. Additionally， a commercial （2-hydroxypropyl）-β-cyclodextrin （Hp-β-CD） chiral column with identical particle size and structure was selected as a reference. This commercial column was used to investigate the selectivity differences among different cyclodextrin derivatives. The enantioseparation and overall chromatographic performance of the CSPs were systematically evaluated under both supercritical fluid chromatography （SFC） and reversed-phase liquid chromatography （RPLC） modes. The evaluation was performed using ten chiral molecular probes： zopiclone， equol， 2-phenylpropionic acid， dobutamine， flutriafol， miconazole， folic acid， catechin， valacyclovir， and chlorphenamine. Results revealed that， under identical chromatographic conditions， the SPP-CSP consistently outperformed the FPP-CSP in terms of enantiomeric resolution， peak sharpness， theoretical plate number， and retention time efficiency. More importantly， the FPP-CSP exhibited a significant loss in resolution when chromatographic conditions were altered to yield equivalent analysis times. In contrast， the SPP-CSP showed only minor adverse effects on resolution when the flow rate was increased to shorten analysis time， highlighting its inherent suitability for ultrafast separations. Moreover， SFC and RPLC modes displayed complementary chiral recognition ranges. Within the overlapping separation scope of both modes， SFC mode achieved higher enantiomeric resolution and superior chromatographic performance. Notably， under RPLC mode， catechin showed high enantiomeric resolution on both CSPs， underscoring system-dependent selectivity differences. Multiple factors—including mobile phase composition （particularly the additive type）， and the stereochemical structure of the analytes—were found to significantly influence enantioseparation outcomes. Under SFC mode， none of the analytes could be eluted when acetonitrile was used as the mobile phase modifier， whereas alcohols effectively enabled elution， with weaker hydrophobicity correlating to stronger elution strength. Among the alcohols tested， methanol offered distinct advantages over isopropanol by maintaining lower backpressure and superior chromatographic performance without compromising resolution. Under RPLC mode， although isopropanol as a mobile phase component provided higher enantiomeric resolution， it resulted in relatively poorer chromatographic performance and higher column pressure drop. Using acetonitrile offered limited flexibility in adjusting elution strength. In both chromatographic modes， the influence trends of mobile phase additives on enantioseparation performance and overall column performance were generally consistent. Mobile phases with acidic additives were more suitable for analyzing acidic analytes such as 2-phenylpropionic acid and folic acid. Mobile phases with ammonium formate were better suited for analyzing basic analytes like chlorphenamine and flutriafol， as well as analytes with pKa values near 7， such as zopiclone. In contrast， NH3 as an additive yielded unsatisfactory results. Compared with the commercial Hp-β-CD chiral column of the same particle size and structure， the SPP-CSP exhibited different selectivity， which varied with the chromatographic mode. Under RPLC mode， the SPP-CSP showed higher resolution for zopiclone， dobutamine， and folic acid. Under SFC mode， it demonstrated higher resolution for equol， folic acid， and valacyclovir. Despite these advances， the study has certain limitations. To enhance compatibility with mass spectrometric detection， normal-phase mode was not investigated. Additives commonly used in chiral compound analysis， such as triethylamine and ammonium trifluoroacetate， were also not employed. Polar organic solvent mode was not investigated either. Additionally， peak symmetry and theoretical plate numbers on the SPP-CSP were generally inferior to those observed on the commercial Hp-β-CD chiral column across both chromatographic modes.

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Simultaneous determination of three tryptamines in foods by ultra performance liquid chromatography-tandem mass spectrometry coupled with hydrophilic column separation LIAO Xiaolei, LIN Qin, MEI Yue, DOU Hongshun, XU Hui, HE Yun, PAN Cheng, JIANG Fengling 2026, 44 (9):  1010-1018.  DOI: 10.3724/SP.J.1123.2025.08022 Abstract ( 174 )   HTML ( 16 )   PDF (809KB) ( 29 )   The illegal addition of substances in ordinary food poses a serious threat to food safety. Therefore， the detection and identification of such additives have long been important research areas in the field of food safety. Especially， illegal additives are showing new trends now， such as emerging functional varieties， new structural derivatives， and clandestine addition practices. Meanwhile， along with the development of online shopping and logistics， new threats pose a substantial challenge to social governance and food safety. In recent years， there are frequent cases of people consuming wild mushrooms containing hallucinogenic tryptamine toxins out of curiosity， and the abuse of tryptamine psychoactive substances also occurs from time to time. Therefore， the development of a robust and sensitive analytical method is necessary for accurately identifying the risks associated with tryptamine psychoactive substances.To address this issue， a novel method based on ultra performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS） combined with an isotopic internal standard and solid-phase extraction purification technique was developed for the simultaneous determination of three tryptamines （psilocin， bufotenine and psilocybin） in ten types of ordinary foods. Several optimization procedures were undertaken， involving the chromatographic conditions， mass spectrometric parameters， and sample extraction and purification protocols. The food samples were extracted and centrifuged， followed by purification using a strong cation exchange solid-phase extraction column. The separation was carried out using a Capcell PAK ST （S-5） hydrophilic interaction chromatographic column. The multi-reaction monitoring （MRM） mode was employed for data acquisition in the positive ion mode， whereas isotopic internal standards were used to quantify the three tryptamines. It was verified that the calibration curves of psilocin， bufotenine， and psilocybin exhibited good linearities （R2>0.995） within the range of 0.025-10.0 ng/mL. The limits of detection （LODs） for psilocin， bufotenine and psilocybin were determined as 0.4， 0.5， and 0.6 µg/kg， respectively， while the limits of quantification （LOQs） were determined as 1.4， 1.7， and 1.9 µg/kg， respectively. The LODs and LOQs demonstrate that the method has the ability to detect minute quantities of tryptamines. The recoveries of the tryptamines were 94.3%-113.7% under three spiked levels， with relative standard deviations （RSDs） ranging from 0.4% to 4.9% （n=6）. The consistent and satisfactory recoveries of tryptamines indicate that this method meets the requirements to accurately quantify the target analytes even in a complex matrix. In summary， this newly developed method is rapid， sensitive， accurate， and compliant with relevant regulatory standards； hence， it is suitable for the determination of psilocin， bufotenine and psilocybin in food matrices. As part of the application of this method， a comprehensive investigation was conducted on ten types of actual food samples， including candies， beverages， wines， succade， coffee， health care products， condiments， cooked meat products， spices and hot pot sauce. As a result， out of 100 samples， 14 samples were found to contain bufotenine. Additionally， one sample had a bufotenine concentration of 7.6 mg/kg. By tracing back， it was discovered that the bufotenine in the positive samples was derived from Zanthoxylum armatum DC. or Zanthoxylum Bungeanum Maxim. Subsequently， 12 samples， containing Zanthoxylum armatum DC. and Zanthoxylum Bungeanum Maxim， were collected and processed using the same method， which revealed the bufotenine in all samples with the content ranging from 23.8 to 885.0 mg/kg. At the same time， it was found that the daughter ion scanning mass spectra of the Zanthoxylum Bungeanum Maxim sample were almost consistent with those of the bufotenine standard. Based on this， it can be firmly concluded that bufotenine is naturally present in Zanthoxylum armatum DC. and Zanthoxylum Bungeanum Maxim. In conclusion， the developed method and the discovery of the content of bufotenine in Zanthoxylum armatum DC. and Zanthoxylum Bungeanum Maxim provide a reference framework for future research in the areas of food safety risk assessment， the screening of illegal additives， and food product development.

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Determination of glufosinate and its metabolite residues in tea by ultra-high performance liquid chromatography-tandem mass spectrometry coupled with precolumn derivatization BI Ruifeng, FU Shihui, DENG Suocheng, FU Meng, ZHANG Weiwei, SONG Yuhua 2026, 44 (9):  1019-1027.  DOI: 10.3724/SP.J.1123.2025.09022 Abstract ( 189 )   HTML ( 20 )   PDF (1078KB) ( 46 )   Tea is an important cash crop in China， and pesticide residues in tea products are among the main issues affecting tea exports. Glufosinate （GLU） is a widely used herbicide in tea gardens and its residues in tea samples have raised health concerns. However， there are few reports on analytical methods for the simultaneous determination of GLU and its metabolite residues in tea. Therefore， the development of suitable analytical methods to monitor the content of GLU and its metabolite residues in tea is essential to ensure compliance with the export quality standards of tea products. In this study， a sensitive analytical method was developed for the determination of GLU and its two main metabolites， N-acetyl-glufosinate （NAG） and 3-［hydroxy（methyl）phosphinoyl］propionic acid （MPP）， in tea. The method is based on ultra-high performance liquid chromatography-tandem mass spectrometry （UHPLC-MS/MS） coupled with precolumn derivatization. Tea samples （2.00 g） were extracted with 20 mL of ultrapure water by shaking， and followed by centrifugation. After freezing treatment， aliquots of the extract were centrifuged at 15 000 r/min. Then 200 μL of the supernatant was evaporated to complete dryness using nitrogen blowdown. The resulting residue was derivatized with triethyl orthoacetate （TEOA） at 80 ℃ for 1.5 h， in the presence of acetic acid as the catalyst. The derivatization mixture was evaporated to dryness and reconstituted with methanol. NAG was transformed into the same reaction product as GLU， and therefore quantified together with GLU. The derivatization products were separated on an Agilent ZORBAX Eclipse Plus C18 column （100 mm×2.1 mm， 1.8 μm）. The mobile phase consisted of an aqueous solution of 0.1% （V/V） formic acid （containing 5 mmol/L ammonium formate） as phase A and acetonitrile as phase B. The gradient elution was carried out as follows： 0–0.5 min， 90%A； 0.5–7.5 min， 90%A–80%A； 7.5–8.0 min， 80%A–10%A； 8.0–10.0 min， 10%A； 10.0–10.1 min， 10%A–90%A； 10.1–12.0 min， 90%A. The separated compounds were detected by tandem mass spectrometry with positive electrospray ionization （ESI+） in multiple reaction monitoring （MRM） mode， and stable isotope-labeled internal standards were used for quantitative analysis. Good linearity was obtained in the 0.5–20 μg/L range； the correlation coefficients （r2） were higher than 0.995， the limits of detection were 2.2–5.3 µg/kg and the limits of quantification were 25 µg/kg. For two representative matrices of green tea and black tea， the average recoveries of GLU and MPP spiked at four levels of 0.025， 0.05， 0.1， and 0.5 mg/kg were 83.9%–105.0%. The intra-day precisions （n=5） ranged from 1.9% to 6.9% and the inter-day precisions （n=10） ranged from 2.6% to 10.3%. Furthermore， the developed method was used to detect GLU and its metabolite residues in 34 tea samples， and the positive detection ratio was 26.5%. In summary， the proposed method is simple， reliable， practical， and suitable for determining GLU and its metabolite residues in various types of tea.

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Determination of 33 non-steroidal anti-inflammatory drug residues in horse urine by QuEChERS-ultra performance liquid chromatography-tandem mass spectrometry ZHANG Xiaonan, MA Zhichao, LIU An, HUANG Yuan, MIN Xuehong, LIU Mei, XIE Zhengqi, WEI Yansong 2026, 44 (9):  1028-1037.  DOI: 10.3724/SP.J.1123.2025.08014 Abstract ( 163 )   HTML ( 26 )   PDF (925KB) ( 27 )   Non-steroidal anti-inflammatory drugs （NSAIDs） are often used to treat horses’ injuries and pain due to long-term training and competitions. In equestrian competitions， NSAIDs do not affect the upper limit of a horse’s athletic ability， but they can enable the horse to perform close to its maximum capacity by reducing inflammation and pain. This not only affects the competition results， but also fails to ensure the health and welfare of the horses. Therefore， it has become crucial to effectively monitor and control NSAIDs residues during equestrian competition. In this study， a rapid screening and determination method for 33 NSAIDs in horse urine was established using QuEChERS pretreatment combined with ultra performance liquid chromatography-tandem mass spectrometry （QuEChERS-UPLC-MS/MS）. The pretreatment process， chromatographic conditions， and mass spectrometric conditions were also optimized. In brief， the target analytes in 1 mL of horse urine samples were extracted with 5 mL of acetonitrile. During extraction， 100 mg of NaCl was added as a salting-out agent， and the mixture was shaken for 3 min. Subsequently， the extract was purified using a QuEChERS method with 300 mg of anhydrous MgSO4， 40 mg of octadecylsilane-bonded silica （C18）， and 40 mg of primary secondary amine （PSA） as sorbents. After centrifugation， the supernatant was dried under nitrogen and reconstituted. The 33 NSAIDs were separated on an Agilent Poroshell 120 EC-C18 analytical chromatographic column （100 mm×3.0 mm，2.7 μm） with gradient elution using （A） 0.1% formic acid aqueous solution and （B） methanol solution as the mobile phases. The gradient elution program was as follows： 0–1 min， 30%B； 1–3 min， 30%B–60%B； 3–12 min， 60%B–85%B； 12–12.1 min， 85%B–95%B； 12.1–14 min， 95%B； 14–14.1 min， 95%B–30%B； 14.1–17 min， 30%B. Then， the target analytes were determined by UPLC-MS/MS in dynamic multiple reaction monitoring （dMRM） mode with positive/negative ion switching. Quantification was performed using the matrix-matched external standard method. The results showed that the method can rapidly and simultaneously determine the 33 NSAIDs in horse urine. The analytes had good linear relationships within their respective ranges， with correlation coefficients of >0.99. The limits of detection （LODs） and quantification （LOQs） were 0.1–1.0 μg/L and 0.9–5.4 μg/L， respectively. The recoveries of the 33 NSAIDs in horse urine were between 70.8% and 123.8% at three spiked levels of LOQ， 20 μg/L and 200 μg/L. The relative standard deviations of all targeted compounds ranged from 1.9% to 14.8%. The method was applied to 10 actual horse urine samples. The results revealed the presence of three NSAIDs， including ketorolac， lornoxicam and naproxen， with contents ranging from < LOQ to 6.87 μg/L. According to the Equine Prohibited Substances List published by the Federation Equestre Internationale （FEI）， ketorolac and naproxen are controlled medications. They are prohibited for use during competition period， as they may mask symptoms and aggravate clinical conditions. However， they are permitted for use during non-competition times. Lornoxicam is a banned substance and is strictly prohibited for use in horses at any time. The proposed method is simple， efficient and accurate， and is suitable for the simultaneous determination of the 33 NSAIDs residues in horse urine samples.

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Determination of two pancreatic stimulants in equine urine using ionic liquid-based deep eutectic solvent-assisted liquid-liquid microextraction and ultra-high performance liquid chromatography-tandem mass spectrometry CHEN Qian, MA Zhichao, LI Yaonan 2026, 44 (9):  1038-1047.  DOI: 10.3724/SP.J.1123.2025.03019 Abstract ( 89 )   HTML ( 14 )   PDF (1262KB) ( 14 )   Acetohexamide （AH） and chlorpropamide （CP） can stimulate pancreatic secretion of insulin and regulate water-salt balance， which may indirectly lead to an increase in adrenaline and potentially enhance the athletic performance of horses. For the protection of horse welfare and the consideration of fair competition， AH and CP were listed as pancreatic stimulants by the Federation Equestre Internationale （FEI）. A method for the detection of pancreatic stimulants in equestrian sports needs to be established. Before analyzing these drugs from biological samples such as urine， it is necessary to perform pre-treatment to separate and concentrate the target analytes. However， there are several disadvantages to using traditional pre-treatment methods， including toxicity and inefficiency. A rapid and environmentally friendly pre-treatment method utilizing ionic liquid-based deep eutectic solvent vortex-assisted liquid-liquid microextraction （IL-DES-VALLME） was developed. Coupled with ultra-high performance liquid chromatography-tandem mass spectrometry （UHPLC-MS/MS）， the approach enabled efficient extraction and sensitive quantification of AH and CP from equine urine. N-Butyl-N-methylmorpholinium bis（（trifluoromethyl）sulfonyl）imide （EMMPNTF2） was chosen as the hydrogen bond acceptor （HBA）， combined with pentafluorophenol （PFP） acting as the hydrogen bond donor （HBD）. A molar ratio of 1∶4 （HBA/HBD） was identified as the optimum composition of IL-DES. Differential scanning calorimetry （DSC） was utilized to measure the melting point of the synthesized IL-DES. Fourier-transform infrared （FT-IR） spectra and proton nuclear magnetic resonance （1H NMR） spectra were employed to characterize the structure of the IL-DES and investigate the hydrogen bonding interactions between its components. Under the optimum conditions， only 100 μL of IL-DES， 1 mL of equine urine， and 6 min were required. An external standard calibration method was utilized for quantification， and a linear relationship was achieved with a mass concentration range of 0.2-20 000 ng/mL for AH and 0.5-20 000 ng/mL for CP. The coefficients of determination （r2） were all greater than 0.999. The limits of detection （LOD） of the method based on a signal-to-noise ratio of 3 were 0.1 ng/mL for AH and 0.2 ng/mL for CP. The limits of quantification （LOQ） of the method based on a signal-to-noise ratio of 10 were 0.2 ng/mL for AH and 0.5 ng/mL for CP. The absolute values of matrix effects were all less than 20% （-8.9% for AH， -11.2% for CP）. Method accuracy， assessed through recovery studies at multiple concentrations across the linear range， yielded values between 90.2% and 110.4%. Precision， expressed as relative standard deviation （RSD）， was excellent， with intra-day RSDs≤6.6% and inter-day RSDs≤5.8%. The RSDs for robustness were less than 5.7%， and the average carry-over ratios were in the range of 11.4%-17.3%， indicating good method robustness and acceptable carry-over levels for the quantitation of AH and CP in equine urine. The greenness was assessed by the AGREEprep metric （score： 0.63）. Compared with traditional extraction methods， the IL-DES-VALLME method has the advantages of rapidity， simplicity， efficiency， low toxicity， and low cost. Additionally， the application of the proposed approach to real equine urine samples proved its practicability. These advantages make the method very appealing for doping control in equestrian sports.

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Determination of 15 fentanyl analogs and amphetamine-type stimulants in hair by liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry WEI Qi, SU Fuhai, ZHU Xin 2026, 44 (9):  1048-1058.  DOI: 10.3724/SP.J.1123.2025.12005 Abstract ( 54 )   HTML ( 10 )   PDF (1339KB) ( 19 )   Drug abuse is a major global public health problem. Fentanyl analogs and amphetamine-type stimulants （ATS） are widely abused worldwide. Hair analysis can trace drug use history over months. This technique has unique advantages in forensic toxicology. However， its application is limited by a lack of matrix-certified reference materials （CRMs）. At present， the existing CRMs are unable to simultaneously cover both fentanyl analogs and amphetamine-type stimulants. This study established a hair sample preparation method based on a water‑dimethyl sulfoxide‑hydrochloric acid soaking approach， targeting 15 analytes （nine fentanyl analogs and six ATS）. The soaking time was systematically investigated. Drug incorporation into hair reached a maximum at 24 days. A slight decrease was observed at 25 days. This decrease may result from desorption and solvent-induced structural changes in keratin. Therefore， 24 days was selected as the optimal soaking time. Preparation experiments demonstrated that 14 of the 15 drugs were successfully embedded into the hair matrix. This study also applied a dual-platform quantitative strategy for certification. The two platforms were liquid chromatography-tandem mass spectrometry （LC-MS/MS） and gas chromatography-mass spectrometry （GC-MS）. Cross-validation between the two platforms improved the reliability of certified values. Sample pretreatment conditions were optimized using Box-Behnken response surface methodology. Four factors were investigated： extraction temperature， extraction time， liquid-to-solid ratio， and hydrochloric acid concentration. The effects of the four factors on extraction efficiency followed a decreasing order： extraction temperature>extraction time>liquid-to-solid ratio>hydrochloric acid concentration. The optimal extraction conditions were as follows： extraction temperature 40 ℃， extraction time 50 min， liquid-solid ratio 100∶1 （mL/g）， and hydrochloric acid concentration 0.01 mol/L. Method validation was performed according to international guidelines. For LC-MS/MS， the limits of detection （LODs） and quantification （LOQs） were 0.05 pg/mg and 0.25 pg/mg， respectively. For GC-MS， the LODs and LOQs were 0.02 ng/mg and 0.08 ng/mg， respectively. Good linearities were obtained for all 15 drugs. Correlation coefficients （r） were greater than 0.999 for both platforms. Good linearities were obtained for all 15 analytes on both platforms with correlation coefficients >0.999 over the respective concentration ranges Intra-day precisions （n=6） were evaluated as relative standard deviations （RSDs）. Inter-day precision （n=30 over 5 days） was also calculated. For 14 drugs （except amphetamine）， RSD values ranged from 0.2% to 9.4%. All RSDs were below 10%， indicating good repeatability and intermediate precision. Stability of hair extracts was assessed at 1， 24， 48， 72， and 96 h at room temperature. The extracts were stable for at least 96 h when stored at room temperature， with RSDs below 6.0% for LC-MS/MS and below 10% for GC-MS. Recovery tests were performed at three quality control levels （low， medium， high）. For LC-MS/MS， average recoveries ranged from 84.46% to 116.4% （n=3）. For GC-MS， average recoveries ranged from 85.50% to 116.4% （n=3）. All RSDs were below 15%. Matrix effects （MEs） were evaluated by comparing matrix-matched standards with solvent standards. ME values between 80% and 120% （n=3） were observed for both platforms. These results indicate negligible ion suppression or enhancement. Homogeneity of the prepared hair reference material was assessed. The results show that the uniformity of the hair samples is good. The contents of the 14 drugs in the prepared hair samples were determined. For LC-MS/MS， the values ranged from 1.012 ng/mg to 7.830 ng/mg. For GC-MS， the values ranged from 1.087 ng/mg to 7.712 ng/mg. Amphetamine was not detected by either platform， likely due to its high polarity and weak binding to keratin. Most drugs showed good agreement between the two platforms. Relative deviations were below 10% for most analytes. However， methamphetamine showed a deviation of -12%. This may be due to matrix effects in LC-MS/MS. The GC-MS results for methamphetamine were more robust. The dual-platform approach allowed cross-validation and enhanced the reliability of the certified values. In conclusion， a dual-platform method based on LC-MS/MS and GC-MS was successfully applied to certify a new hair matrix reference material. The cross-validation strategy enhances the accuracy and traceability of the certified values. This work provides a valuable tool for quality control in forensic toxicology laboratories. The prepared reference material and validated method will facilitate inter-laboratory comparisons. They will also support the monitoring of drug abuse in forensic and clinical settings.

Instrument Development and Applications

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Development and performance testing of a high-sensitivity pulsed flame photometric detector CHEN Junbin, CAI Haoyuan, DENG Zhihan, JIN Yujie, SUN Jianhai 2026, 44 (9):  1059-1073.  DOI: 10.3724/SP.J.1123.2026.03027 Abstract ( 99 )   HTML ( 12 )   PDF (2776KB) ( 22 )   The conventional flame photometric detector （FPD） is widely used for sulfur-selective gas chromatography. However， the FPD is sensitive to hydrocarbon backgrounds. Its sulfur response also depends strongly on flame stability. These factors limit stable trace sulfur determination in complex matrices. A pulsed flame photometric detector （PFPD） provides a time-resolved approach to this problem. Sulfur emission appears later than most hydrocarbon background emissions after pulsed combustion. A suitable acquisition window can therefore improve sulfur selectivity. In this study， a high-sensitivity single-channel PFPD was designed and tested. The aim was to establish reproducible operating conditions for trace sulfur analysis. The detector consisted of five functional modules： the combustion and ignition module， the gas supply module， the optical collection and detection module， the temperature-control module， and the mechanical support and sealing module. The combustion zone consisted of a vertically mounted quartz chamber. The chamber had an outer diameter of 4 mm. Its inner diameter was 2 mm. Its total length was 17.5 mm. The effective combustion length was 12 mm. The calculated chamber volume was 37.68 mm3. Numerical simulation was used to examine flame propagation and self-extinction. A 12 mm effective length maintained a stable finger-shaped flame front. The flame was self-terminated near the lower limiting orifice at about 1.97 ms. The hydroxyl radical mass fraction decreased close to baseline within 5 ms， whereas the temperature decayed more gradually and approached its initial level at approximately 30 ms. These results supported the chamber design for periodic pulsed combustion. The optical unit used a quartz light guide and a BG-12 band-pass filter. The filter matched the sulfur emission band near 394 nm. A photomultiplier tube （PMT） recorded the time-resolved emission signal. Two electronic pneumatic control （EPC） units were used for gas regulation. One unit controlled hydrogen and air for the ignition chamber. The other unit controlled hydrogen and air for the combustion chamber. This design separated ignition conditions from analytical combustion conditions. It also reduced uncertainty caused by coupled gas adjustment. The optimization started with the ignition chamber. Then the combustion chamber was optimized under the fixed ignition baseline. Finally， detector temperature and PMT voltage were evaluated. Peak area， sensitivity， and signal-to-noise ratio （SNR） were used as indicators. Gas chromatographic tests used a sulfur-specific quartz capillary column. Nitrogen was used as the carrier gas. The gate delay was 6 ms. The gate width was 18 ms. The trigger level was 500 mV. A stable pulsed flame was obtained at an ignition-chamber hydrogen flow of 8.0 mL/min. The corresponding ignition-chamber air flow was 19.0 mL/min. Under this ignition baseline， the combustion chamber was further adjusted. A higher sulfur response was obtained at 5.0 mL/min hydrogen. The corresponding air flow was 3.7 mL/min. Detector temperature also affected the delayed sulfur emission. The response was low at 110-130 ℃. At about 150 ℃， the delayed sulfur signal was higher. Peak area and sulfur sensitivity were also higher at this temperature. Higher temperatures from 170 to 250 ℃ reduced the peak area and sensitivity. PMT voltage affected signal amplitude， SNR， and waveform fidelity. Increasing the voltage from 590 to 710 V improved the SNR. At 730 V， the delayed emission plateau showed peak clipping. This behavior indicated saturation or nonlinear response in the detection chain. Dynamic dilutions of a 10 μmol/mol hydrogen sulfide （H₂S） standard gas were used to evaluate the linear range. A 1.1 μmol/mol H₂S standard gas was used for the quantitative repeatability test and， after 30-fold dynamic dilution， for determination of the sulfur detection limit. The quantitative repeatability， evaluated from the peak areas of seven consecutive injections， was 0.37%. The sulfur detection limit was 4.1×10⁻1³ g/s， and the linear range spanned approximately two orders of magnitude. The developed PFPD showed stable pulsed combustion behavior. It also provided reliable quantitative response for trace sulfur detection. The dual-EPC design helped clarify the relationship between ignition and analytical combustion. The optimized conditions provide an experimental basis for self-developed PFPD systems.

Teaching Research

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Self-designed experiment in instrumental analysis： online solid phase extraction-high performance liquid chromatography- post column derivatization for the determination of trace pesticide residues in vegetables LI Yan, LIU Yuntao, HUANG Xien, ZHOU Ziyi, WANG Ziqiu, WANG Jing, DING Fei, NAN Jing, TANG Anna 2026, 44 (9):  1074-1081.  DOI: 10.3724/SP.J.1123.2025.10020 Abstract ( 131 )   HTML ( 10 )   PDF (1291KB) ( 35 )   In line with modern educational concepts and the demand for innovative talents， a course focused on self-designed experiments has been incorporated into the traditional instrumental analysis curriculum. This initiative aims to enhance students’ ability to apply knowledge effectively. While mastering instrument operation， students are encouraged to anticipate potential challenges during experiments. Under instructor guidance， students constructed an online system for solid-phase extraction coupled with liquid chromatography and post-column derivatization with fluorescence detection. They addressed real analytical needs such as improving sensitivity and precision， minimizing interference， and conducting rapid analyses of trace carbamate pesticides in vegetable samples. This self-designed liquid chromatography experiment course， tailored to students’ learning characteristics and interests， successfully engages their initiative and fosters independent innovation capabilities. As a result， it also improves teaching effectiveness and enhances learning efficiency.

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Open experiment of modern instrumental analysis course： preparation of biomass-derived functional materials and their enrichment application of antibiotics in water environment LEI Xiaoyun, JIN Lingxia, WU Xiaoping 2026, 44 (9):  1082-1089.  DOI: 10.3724/SP.J.1123.2025.10028 Abstract ( 166 )   HTML ( 9 )   PDF (1645KB) ( 24 )   To cultivate systematic thinking and innovation capabilities in senior undergraduate students majoring in chemistry and related fields， this project proposes an open-ended experiment that focuses on the preparation， characterization， and application of biomass-derived functional materials. The experiment incorporates essential procedures such as the preparation of biochar materials and the polymer synthesis. Characterization of the material’s structure and hydrophilicity/hydrophobicity is performed using scanning electron microscopy， infrared spectroscopy， and water contact angle measurements. During the application phase， the self-prepared materials are utilized to adsorb glycopeptide antibiotics from real water samples， followed by quantitative analysis using high performance liquid chromatography. Throughout the experiment， students will enhance their ability to integrate multidisciplinary knowledge， master skills across the entire analytical workflow—from sample pretreatment to instrumental analysis—while also improving their competencies in material preparation， instrument operation， and data analysis. Through this hands-on practice， students will develop a practical understanding of the application of analytical technologies in environmental remediation and monitoring， thereby strengthening their innovative capacity to identify and solve complex chemical problems. Furthermore， the implementation of this open-ended experiment contributes to advancing the resource utilization of biomass materials， aligning with the demands of a low-carbon economy.

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Teaching practice of instrumental analysis course based on inquiry-based learning and critical thinking： a case study of competency development for pharmacy students DING Bo 2026, 44 (9):  1090-1099.  DOI: 10.3724/SP.J.1123.2025.09002 Abstract ( 198 )   HTML ( 9 )   PDF (795KB) ( 37 )   Instrumental analysis is a crucial foundational course for pharmacy majors， and its teaching effectiveness directly relates to the cultivation of students’ analytical testing abilities， scientific research literacy， and innovative thinking. Current teaching commonly faces problems such as complex content systems， difficulty in understanding principles， and disconnection between theory and experiments， resulting in students’ lack of active inquiry awareness and critical thinking. To address these issues， this study takes pharmacy students from 2019-2023 classes at the School of Pharmacy， Guangzhou Medical University as subjects， exploring a teaching model that combines inquiry-based teaching with the cultivation of critical thinking. By constructing a stepwise inquiry approach that progresses from imitative to comparative to case-based learning and designing problem-oriented learning tasks and reflective assessment mechanisms， the study aims to guide students in achieving knowledge construction and cognitive enhancement within authentic problem contexts. Teaching practice results indicate that this model effectively promoted students’ transition from passive acceptance to active inquiry， significantly improving their analytical testing abilities， scientific research literacy， and innovative capabilities. However， some students still exhibited habitual thinking in knowledge transfer and analysis strategy selection， and the depth of critical reasoning needs to be further strengthened. This study provides a systematic pathway and empirical evidence for the teaching reform of instrumental analysis courses， and is of significant importance for cultivating high-quality pharmacy professionals with innovative capabilities.