Simultaneous Determination of Four Fatty Acids in Coix Seeds via Gas Chromatography
by
Qiang Ai
1,
Hui Wang
1,
Chenghong Xiao
2,
Changgui Yang
2,
Shanmin Song
1,
Mingxiang Zhang
1,
Jiandong Tang
3,* and
Yang Lei
1,* 1
Guizhou Vocational College of Agriculture, Guiyang 551400, China
2
Resource Institute for Chinese and Ethnic Materia Medica, Guizhou University of Traditional Chinese Medicine, Guiyang 550025, China
3
College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
*
Authors to whom correspondence should be addressed.
ChemEngineering 2025, 9(5), 98; https://doi.org/10.3390/chemengineering9050098
Submission received: 28 June 2025
/
Revised: 20 August 2025
/
Accepted: 9 September 2025
/
Published: 11 September 2025
(This article belongs to the Special Issue Advances in Sustainable and Green Chemistry)
Abstract
The aim of this study was to establish a method named simultaneous determination for the content of four fatty acids in Coix seeds and provide a reference for the quality control of this type of medicinal ingredient. The contents of four fatty acids in Coix seeds were determined via gas chromatography, and the method was subsequently validated. The linear ranges of palmitic acid, stearic acid, oleic acid and linoleic acid were 282.50–2825.00, 262.00–1572.00, 425.20–2976.75 and 304.50–1218.00 µg/mL, respectively. The RSD values of precision, repeatability and stability were less than 3.00% (n = 6), with recoveries of 98.82–102.05% (RSD 2.22–4.60%, n = 6). The contents of palmitic acid, stearic acid, oleic acid and linoleic acid in the 24 batches of Coix seeds were 0.11–0.32%, 0.06–0.08%, 0.35–1.17% and 0.31–0.73%, respectively. Oleic acid had the highest content, followed by linoleic acid, palmitic acid, and stearic acid. The detection method established in this experiment was implemented rapidly and accurately, was reproducible, and could simultaneously determine the contents of four fatty acids in Coix seeds. This study provides a reference for evaluating the quality of Coix seeds obtained from different habitats.
1. Introduction
The Coix seed (Coix lacrymajobi L. var. mayuen (Roman.)) Stapf is the dried mature seed of the Gramineae plant Coix lacrymajobi [1,2] and is considered an important medicinal and edible resource. Currently, the main production areas are Guizhou, Yunnan and Fujian [3,4]. Recent pharmacological studies have revealed that Coix seeds also regulate lipid metabolism and the gut microbiota and have antiviral, antihypertensive, anti-inflammatory, anticantrant, hypoglycemic and immunoregulatory effects [5,6,7,8]. Currently, domestic and international researchers extract and identify various pharmacologically active components from multiple parts of Coix seeds [9].
Lipids are important components of Coix seeds and contain many essential fatty acids for the human body. Lipids are also the main source of medicinal nutrients in Coix seeds, but they differ considerably across varieties [10]. Coix seeds contain a wide range of unsaturated fatty acids, including oleic acid, linoleic acid and linolenic acid, and unsaturated fatty acids account for the majority of the main fatty acid composition [5,11]. Since coixenolide was initially isolated from Coix seeds in 1961, researchers have focused on its lipid components. Coix seeds contain approximately 6% oil, with triglycerides accounting for 86.92–94.43%, and the remainder primarily consists of diglycerides, monoglycerides, and fatty acid esters. Hou et al. [12] identified 20 triglycerides and 12 diglycerides via mass spectrometry (MS). The oil from Coix seeds is rich in unsaturated fatty acids (approximately 85%) and primarily takes the form of oleic acid, linoleic acid and stearenoic acid [13,14].
Most studies on the quality of Coix seeds have recently focused on glycerol triacyl glycerides as quality evaluation indicators [15]; however, studies on other fatty acid components with similar bioactive properties are limited. Domestic scholars have determined the contents of seven types of glycerol triacyl glycerides and two types of unsaturated fatty acids in Coix seeds developed as herbal medicines in different regions of China and evaluated the quality of these ingredients. The hybrid UPLC–Triple–TOF–MS liquid–chromatography–MS method was used to analyse the fatty acids in Coix seeds and their esters. Whilst 29 types of fatty acids and their esters have been detected, this method requires expensive equipment and is unsuitable for routine quality evaluation in ordinary laboratories [15,16].
Fatty acids, the basic components of lipids and cell membrane lipids, have important physiological functions; they also serve as nutrients and energy sources for cells and play crucial roles in human life activities. Common methods for determining fatty acid content include gas chromatography (GC) and GC–MS [17,18]. GC plays a crucial role in the quality control analysis of traditional Chinese medicinal ingredients and is used primarily to analyse volatile and semivolatile ingredients and components that are considered volatile via derivatisation (e.g., fatty acid composition analysis). The high separation efficiency, high sensitivity, good reproducibility and quantitative accuracy of GC make it a powerful tool for the modernisation and standardisation of traditional Chinese medicine research. However, fatty acids are difficult to volatilise and elute from GC columns because of their high boiling points; thus, they require long retention times and have severe peak tailing, which affects their quantitative accuracy. Derivatisation is necessary to lower boiling points and facilitate measurement [15]. Many methods can be used to methylate fatty acids, including acid and alkali treatments [19]. However, acid treatments take a long time to complete, and diazomethane is unstable, explosive and carcinogenic, posing safety risks during use. In this study, alkali treatment was selected for derivatisation. GC analysis of fatty acids initially involves converting fatty acids into fatty acid methyl esters. The components are subsequently separated on the basis of differences in distribution between the mobile phase and stationary phase and on the basis of variations in adsorption capacity. Currently, GC analysis of fatty acids is widely used by research institutions and enterprises at the domestic level. Zhou et al. [20] established an internal standard method for GC to simultaneously determine the contents of myristic acid methyl ester, palmitic acid methyl ester, stearic acid methyl ester, oleic acid methyl ester, linoleic acid methyl ester, and α-linolenic acid methyl ester in Brassica campestris Linn pollen. This method is simple to use, accurate, and specific, and can be used for quality control of rapeseed pollen. Ye et al. [21] established a GC method to simultaneously determine the contents of four fatty acids, namely, palmitic acid, linolenic acid, cis-11-eicosenoic acid, and erucic acid, in Descurainia sophia.
Given the critical role of fatty acids in biological processes and their potential as important quality markers for Job’s tears, an analytical method that is suitable for routine laboratory use and can accurately quantify multiple key fatty acids in Job’s tears is urgently needed. In this manner, the current limitations related to overreliance on a single triglyceride indicator and the limited accessibility of advanced technologies can be overcome. Owing to its widespread availability and advantages in analysing volatile/volatilised substances, the GC platform is an ideal solution, but a safe and efficient derivatisation strategy must first be developed.
This study establishes a GC method for simultaneously determining the contents of oleic acid, linoleic acid, palmitic acid and stearic acid in Coix seeds via GC. This method differs from traditional evaluation systems that focus solely on triglycerides. Consequently, comprehensive fatty acid information can be collected, and the high cost and complexity of technologies, such as the hybrid UPLC–Triple–TOF–MS methodology, can be avoided. The wide availability of the GC platform also allows for the adoption of a safe and highly efficient alkaline derivatisation method, which can avoid the use of time-consuming methods requiring hazardous reagents and acid. Furthermore, GC offers the advantages of simple operation, rapid analysis, good peak shape, high selectivity, high sensitivity, and good specificity. The use of GC can help overcome the limitations of single-component quality evaluation of Coix seeds whilst providing a reliable and practical analytical method for the routine quality control and comprehensive evaluation of Coix seed.
2. Materials and Methods
2.1. Instrumentation
The following instruments were used: a gas chromatograph (model: 7890B, Agilent Technologies, Inc., Santa Clara, CA, USA) with DB-WAX, as the polyethylene glycol chromatography capillary column (configuration: 30 m × 320 μm × 0.25 μm) from Agilent Technologies, Inc., Santa Clara, CA, USA; a constant-temperature water bath (model: DRHH-S4) from Shanghai Shuangjie Co., Ltd., Shanghai, China; a vortex mixer (model: XW-80A) from Shanghai Chitang Industrial Co., Ltd., Shanghai, China; and an electronic balance (model: ME20) from Mettler Toledo, Zurich, Switzerland.
2.2. Chemicals and Reagents
Palmitic acid (batch no. AF 20022921), stearic acid (batch no. AF 20100218) and oleic acid (batch no. AF 8112892) were all 98% pure. Linoleic acid (batch no. AF 20062852) has a purity of 95%. All acids were purchased from Chengdu Efa Biotechnology Co., Ltd. (Chengdu, China). Petroleum ether (60 °C to 90 °C), C2H5OH, C6H14, 14% BF3–MeOH, KOH–MeOH, C4H10O, MeOH, NaCl and NaOH were all of analytical grade.
2.3. Experimental Materials
A total of 24 batches of Coix lacryma-jobi L. var. ma-yuen (Roman.) Stapf-dried mature seeds were collected from Chengdu (Sichuan), Anguo (Hebei), Zhangshu (Jiangxi), Yulin (Guangxi) and Guiyang (Guizhou), China. The samples were identified as Coix lacryma-jobi L. var. ma-yuen (Roman.) Stapf. Detailed information about the samples is shown in Table 1.
2.4. Chromatographic Conditions
The injection port temperature was 250 °C, and the detector temperature was 250 °C. The initial temperature of the column was 220 °C and held for 3 min, increased at 3 °C/min to 230 °C and held for 1 min, increased at 4 °C/min to 240 °C and held for 1 min, and then decreased at 8 °C/min to 220 °C. For the carrier gas, high-purity nitrogen with a column flow rate of 1 mL/min; a tail gas flow rate: of 25 mL/min, a hydrogen flow rate of 40 mL/min, an air flow rate of 400 mL/min, a split ratio of 50:1 and an injection volume of 1 μL were used.
2.5. Preparation of the Mixed Reference Solution
Appropriate amounts of palmitic acid, stearic acid, oleic acid, and linoleic acid were weighed accurately and placed in 10 mL stoppered graduated test tubes. Two millilitres of 0.8 mol/L KOH–MeOH solution was added. The mixture was incubated at 60 °C in a water bath for 20 min under continuous shaking and then removed and cooled to room temperature. Two millilitres of 14% BF3–MeOH solution was added, and the mixture was shaken and placed in a 60 °C water bath for 15 min, and then removed and cooled to room temperature. Two millilitres of C6H14 was added, and the mixture was shaken. Two millilitres of saturated NaCl solution was added and allowed to stand until the liquid layers separated; then, the upper clear liquids were removed. Reference standard solutions with concentrations of 2.825, 2.62, 4.2525, and 3.045 mg/mL were prepared. Appropriate amounts of these reference standard solutions were subsequently diluted with C6H14. This process yielded a mixed reference solution containing 0.70624 mg/mL palmitic acid, 0.655 mg/mL stearic acid, 1.0631 mg/mL oleic acid, and 0.7612 mg/mL linoleic acid.
2.6. Preparation of the Test Solution
Powdered Coix seeds were weighed accurately to 0.5 g and placed in a conical flask. Twenty millilitres of the mixed solvent anhydrous ethanol–petroleum ether (1:1, v/v) was added using a precision pipette. The flask was weighed, and ultrasonic extraction (500 W and 40 kHz) was performed for 35 min. The abovementioned mixed solvent was added to compensate for any weight loss, shaken and filtered. Five millilitres of the filtrate was precisely aspirated to 5 mL and concentrated in a water bath to remove the extraction solvent, and subsequently obtain the Coix seed oil. The methylation process involved the following process: 2 mL of 0.8 mol/L KOH–MeOH solution was added to the Coix seed oil, which was reflux-saponified at 60 °C in a water bath for 20 min, and 2 mL of 14% BF3–MeOH solution was immediately added. Methylation was continued at the same temperature for 15 min. After cooling, 2 mL of hexane was added, the mixture was shaken, 2 mL of saturated sodium chloride solution was added, and the mixture was allowed to stand until the liquid layers separated. The contents of palmitic acid, stearic acid, oleic acid, and linoleic acid were determined.
2.7. Data Analysis
Excel 2019, SPSS 27, and GraphPad 10 were used for statistical data management and data analysis, respectively. Origin 2024 was used for visualisation, and the obtained results were processed by ANOVA with 95% confidence (p ≤ 0.05).
3. Results and Discussion
3.1. Chromatographic Conditions Screening
GC conditions are critical for peak shape and resolution. Column temperature and temperature programming directly affect the peak width and resolution. Low temperatures favour separation but cause peak broadening, whereas high temperatures have the opposite effect. The carrier gas flow rate must be maintained near the optimal value to ensure column efficiency and sharp peaks. When the injection port temperatures are insufficient, they cause peak tailing or splitting; when they are excessive, they cause decomposition. The stationary phase of the chromatographic column is used to determine the resolution, but the column length and inner diameter affect the peak resolution and width. An insufficient detector temperature causes peak tailing of high-boiling compounds. Optimisation requires the coordinated balancing of all the parameters [22,23,24]. Therefore, in this study, the effects of five chromatographic conditions on peak shape and resolution were compared (Table 2). As condition 4 yielded the best peak shape and resolution, it was selected as the chromatographic condition for analysis. Figure 1 shows the chromatograms of the reference solution and sample solution under these conditions.
3.2. Standard Curve and Linear Range
Precise amounts of the mixed reference solution described in Section 2.5 were diluted to different concentrations to prepare reference standards. These were injected and analysed under the chromatographic conditions specified in Section 2.4. Linear regression was conducted. The plotting concentration was set as the x-axis, and the peak area was set as the y-axis. The four fatty acids exhibited good linear relationships (R ≥ 0.9990) and met the analytical requirements. The results are presented in Table 3. These results further validate the advantages of GC analysis in effectively determining fatty acid content.
3.3. Precision Experiment
A pipette was used to transfer an appropriate amount of the mixed reference solution mentioned in Section 2.5. Six consecutive injections were conducted for determination, and the peak areas. were recorded. The RSD values for the peak areas of palmitic acid, stearic acid, oleic acid, and linoleic acid were 0.66%, 0.56%, 0.58% and 0.60%, respectively, at n = 6. These findings indicate good instrument precision.
3.4. Repeatability Test
Precisely measured samples of powdered Coix seeds were taken from batch S12. Each of the six samples weighed 0.5 g. Test solutions were prepared according to the method described in Section 2.6, and the chromatographic conditions specified in Section 2.4 were used for detection. The contents of the four fatty acids in the test samples were calculated. The RSD values for the four fatty acids were all less than 3.0%. Therefore, the method has good repeatability.
3.5. Stability Test
The test solution prepared via the method described in Section 2.6 was left at room temperature, sampled and measured at 0, 2, 4, 8 and 12 h. The peak areas were recorded, and the content was calculated. The RSD values of the four fatty acids measured within the test time were all less than 3.0%. Therefore, the test solution is stable when stored at room temperature for 12 h.
3.6. Spiked Recovery Test
Six samples of powdered Coix seeds from batch S12 were weighed at 0.25 g each. These powdered samples were placed in 50 mL stoppered conical flasks, and an appropriate amount of the mixed reference standard mentioned in Section 2.5 was added. The test solution mentioned in Section 2.6 was employed, and the sample was analysed GC the conditions specified in Section 2.4. The recovery rate of the added sample was calculated. The average recovery rates of the four fatty acids were 98.82–102.05%, with RSD values ranging from 2.22 to 4.60%. The results are shown in Table 4. Hence, the method has good accuracy and meets the requirements for content determination.
3.7. Testing and Analysis of Samples from Different Origins
The collected samples were taken, and the test solutions were prepared according to the methods described in Section 2.5. Each sample was injected and analysed separately under the chromatographic conditions specified in Section 2.4. The contents of the four fatty acids in each test sample were calculated via the external standard method. The results are shown in Table 5. The contents of palmitic acid, stearic acid, oleic acid and linoleic acid were 0.11–0.32%, 0.06–0.08%, 0.35–1.17% and 0.31–0.73%, respectively. The total content of the herbal materials in the 24 batches of Coix seeds ranged from 0.83% to 2.30%. The highest total content of the four fatty acids was found in the S20 sample from Yulin (Guangxi), followed by the S10 sample from Anguo (Hebei), and the lowest content was in the S24 sample from Guiyang (Guizhou). However, from a regional perspective, the total amount of medium-chain fatty acids in the production areas of Anguo (Hebei), Yulin (Guangxi) and Chengdu (Sichuan) is significantly greater than that in Zhangshu (Jiangxi) and Guiyang (Guizhou). The contents of the four fatty acids of the herbal medicines from 24 batches of Coix seeds obtained from different regions were entered into GraphPad for differential analysis. The total contents of the four fatty acids in Coix seeds from the five regions were not significantly different (p > 0.05). At the regional level, the total content of the four fatty acids in Coix seeds from Anguo (Hebei), Yulin (Guangxi) and Chengdu (Sichuan) was significantly greater than that in Coix seeds from Zhangshu (Jiangxi) and Guiyang (Guizhou).
3.8. Clustering Analysis
The contents of the four fatty acids in the herbal medicines from 24 batches of Coix seeds obtained from different regions were input into SPSS 27 for clustering analysis. The intergroup mean linkage method was used, and the sum of squared deviations method was employed for clustering. The results visualised as a dendrogram are shown in Figure 2. The contents of the four fatty acids indicate that the herbal medicines from 24 batches of Coix seeds can be clustered into four categories. The first group includes batches S1, S5, S6, S7, S13, S15, S19, and S21. The second group includes batches S14 and S23. The third group includes batch S24. The fourth group includes batches S10, S18 and S20. The clustering results did not reveal significant correlations between the fatty acid content and origin region, which is consistent with the findings presented in Section 3.7.
4. Conclusions
This study established a simple, accurate, and reliable method of GC for the simultaneous determination of four fatty acids. The average recovery rates of palmitic acid, stearic acid, oleic acid and linoleic acid from the Coix seeds studied were 98.82–102.05%, and the relative standard deviations were 2.22–4.60%. The method has a short analysis time and can be used for the quality analysis of herbal medicines with Coix seeds. The contents of palmitic acid, stearic acid, oleic acid and linoleic acid in the 24 batches were 0.11–0.32%, 0.06–0.08%, 0.35–1.17% and 0.31–0.73%, respectively. The content of oleic acid was the highest, followed by linoleic acid, palmitic acid and stearic acid. The fatty acid contents of Coix seeds from Guizhou and Yunnan were not significantly different. The differences in the quality of Coix seeds from Guizhou were relatively small, indicating stable quality. The results of the GC analysis of the fatty acid contents of Coix seeds still lag behind those of UPLC–MS, GC–MS and HPLC. Nonetheless, the goal of this study was to develop a low-cost analytical method for detecting fatty acids in Coix seeds that can be tested in ordinary laboratories.
Author Contributions
Conceptualization, Q.A. and H.W.; methodology, Q.A. and C.X.; software, Q.A. and H.W.; validation, C.X. and S.S.; formal analysis, C.Y. and C.X.; investigation, S.S. and M.Z.; resources, Y.L. and M.Z.; data curation, Q.A. and C.Y.; writing—original draft, Q.A. and J.T.; writing—review and editing, C.X. and Y.L.; visualisation, Q.A. and H.W.; supervision, J.T. and Y.L.; project administration, Y.L.; funding acquisition, Y.L. All authors have read and agreed to the published version of the manuscript.
Funding
This study was supported by the National Natural Science Foundation of China (U1812403-2).
Data Availability Statement
The data presented in this study are available upon request from the corresponding author.
Conflicts of Interest
The authors declare no conflicts of interest.
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Figure 1.
GC chromatograms of mixed reference standard (A), Condition 1 (B), Condition 2 (C), Condition 3 (D), Condition 4 (E), and Condition 5 (F). (1. Palmitic acid; 2. Stearic acid; 3. Oleic acid; 4. Linoleic acid).
Figure 1.
GC chromatograms of mixed reference standard (A), Condition 1 (B), Condition 2 (C), Condition 3 (D), Condition 4 (E), and Condition 5 (F). (1. Palmitic acid; 2. Stearic acid; 3. Oleic acid; 4. Linoleic acid).
Figure 2.
Cluster analysis of 24 batches of Coix seeds.
Table 1.
Information on 24 batches of Coix seeds samples.
| Sample Number | Place of Origin | Sample Number | Place of Origin |
|---|---|---|---|
| S1 | Chengdu, Sichuan | S13 | Zhangshu, Jiangxi |
| S2 | Chengdu, Sichuan | S14 | Zhangshu, Jiangxi |
| S3 | Chengdu, Sichuan | S15 | Zhangshu, Jiangxi |
| S4 | Chengdu, Sichuan | S16 | Yulin, Guangxi |
| S5 | Chengdu, Sichuan | S17 | Yulin, Guangxi |
| S6 | Anguo, Hebei | S18 | Yulin, Guangxi |
| S7 | Anguo, Hebei | S19 | Yulin, Guangxi |
| S8 | Anguo, Hebei | S20 | Yulin, Guangxi |
| S9 | Anguo, Hebei | S21 | Guiyang, Guizhou |
| S10 | Anguo, Hebei | S22 | Guiyang, Guizhou |
| S11 | Zhangshu, Jiangxi | S23 | Guiyang, Guizhou |
| S12 | Zhangshu, Jiangxi | S24 | Guiyang, Guizhou |
Table 2.
Chromatographic conditions.
| Condition | Chromatographic Conditions | Result | ||||
|---|---|---|---|---|---|---|
| T0/°C | t1/min | r (°C/min) | T1/°C | t2/min | ||
| 1 | 200 | 4 | 5 | 230 | 6 | Chromatographic peaks are not separated. |
| 2 | 200 | 4 | 3 | 230 | 6 | Chromatographic peaks have tails and are asymmetrical. |
| 3 | 200 | 4 | 4 | 230 | 6 | Both peak shape and resolution are good. |
| 4 | 200 | 3 | 4 | 230 | 6 | Both peak shape and resolution are good. |
| 5 | 220 | 3 | 4 | 230 | 6 | Chromatographic peaks are not separated. |
“T0” indicates initial temperature; “t1” indicates the holding time for the initial temperature; “r” indicates the warming rate; “T0” indicates termination temperature; “t2” indicates the holding time for the termination temperature.
Table 3.
Standard curves, linear ranges, and correlation coefficients for four fatty acids.
| Fatty Acid | 1 SC | 2 LR/μg/mL | 3 r |
|---|---|---|---|
| Palmitic acid | Y = 0.8389x−10.516 | 282.50~2825.00 | 1.0000 |
| Stearic acid | Y = 1.1369x−64.786 | 262.00~1572.00 | 0.9996 |
| Oleic acid | Y = 0.8104x−20.604 | 425.25~2976.75 | 0.9990 |
| Linoleic acid | Y = 1.0051x−143.57 | 304.50~1218.00 | 0.9990 |
“1 SC” indicates standard curves; “2 LR” indicates linear ranges; “3 r” indicates correlation coefficient.
Table 4.
Results of sample recovery tests.
| Fatty Acid | 1 SW (g) | 2 SC (mg) | 3 AV (mg) | 4 AA (mg) | 5 RR% | 6 ARR% | RSD% |
|---|---|---|---|---|---|---|---|
| Palmitic acid (PA) | P | 0.027 | 0.056 | 0.028 | 101.81 | 99.40 | 3.75 |
| 0.2500 | 0.027 | 0.055 | 0.028 | 98.23 | |||
| 0.2499 | 0.027 | 0.055 | 0.028 | 98.27 | |||
| 0.2502 | 0.028 | 0.054 | 0.028 | 94.56 | |||
| 0.2499 | 0.027 | 0.057 | 0.028 | 105.42 | |||
| 0.2502 | 0.028 | 0.055 | 0.028 | 98.14 | |||
| Stearic acid (SA) | 0.2500 | 0.015 | 0.028 | 0.013 | 100.79 | 102.05 | 4.60 |
| 0.2500 | 0.015 | 0.028 | 0.013 | 100.02 | |||
| 0.2499 | 0.015 | 0.029 | 0.013 | 107.76 | |||
| 0.2502 | 0.015 | 0.028 | 0.013 | 99.91 | |||
| 0.2499 | 0.015 | 0.028 | 0.013 | 96.22 | |||
| 0.2502 | 0.015 | 0.029 | 0.013 | 107.60 | |||
| Oleic acid (OA) | 0.2500 | 0.087 | 0.174 | 0.085 | 101.79 | 98.82 | 2.22 |
| 0.2500 | 0.087 | 0.170 | 0.085 | 97.08 | |||
| 0.2499 | 0.087 | 0.169 | 0.085 | 95.94 | |||
| 0.2502 | 0.088 | 0.172 | 0.085 | 99.33 | |||
| 0.2499 | 0.087 | 0.173 | 0.085 | 100.65 | |||
| 0.2502 | 0.088 | 0.171 | 0.085 | 98.15 | |||
| Linoleic acid (LA) | 0.2500 | 0.077 | 0.137 | 0.060 | 99.19 | 100.83 | 3.84 |
| 0.2500 | 0.077 | 0.136 | 0.060 | 97.53 | |||
| 0.2499 | 0.077 | 0.138 | 0.060 | 100.91 | |||
| 0.2502 | 0.078 | 0.140 | 0.060 | 104.06 | |||
| 0.2499 | 0.077 | 0.141 | 0.060 | 105.91 | |||
| 0.2502 | 0.078 | 0.136 | 0.060 | 97.40 |
“1 SW” indicates sample weight; “2 SC” indicates sample content; “3 AV” indicates actual value; “4 AA” indicates addition amount; “5 RR” indicates recovery rate; “6 ARR” indicates average recovery rate.
Table 5.
Sample content determination results.
| Sample Number | PA (%) | SA (%) | OA (%) | LA (%) | Total Amount (%) |
|---|---|---|---|---|---|
| S1 | 0.27 | 0.08 | 1.01 | 0.65 | 2.01 |
| S2 | 0.25 | 0.07 | 0.89 | 0.57 | 1.78 |
| S3 | 0.23 | 0.07 | 0.86 | 0.56 | 1.72 |
| S4 | 0.25 | 0.07 | 0.88 | 0.58 | 1.78 |
| S5 | 0.23 | 0.07 | 0.84 | 0.55 | 1.69 |
| S6 | 0.26 | 0.08 | 0.95 | 0.63 | 1.92 |
| S7 | 0.26 | 0.07 | 0.92 | 0.60 | 1.85 |
| S8 | 0.25 | 0.07 | 0.88 | 0.58 | 1.78 |
| S9 | 0.22 | 0.07 | 0.82 | 0.55 | 1.66 |
| S10 | 0.30 | 0.08 | 1.14 | 0.69 | 2.21 |
| S11 | 0.22 | 0.07 | 0.83 | 0.54 | 1.66 |
| S12 | 0.19 | 0.07 | 0.74 | 0.49 | 1.49 |
| S13 | 0.22 | 0.07 | 0.80 | 0.54 | 1.63 |
| S14 | 0.18 | 0.07 | 0.68 | 0.47 | 1.4 |
| S15 | 0.22 | 0.07 | 0.81 | 0.52 | 1.62 |
| S16 | 0.17 | 0.06 | 0.61 | 0.44 | 1.28 |
| S17 | 0.21 | 0.07 | 0.74 | 0.53 | 1.55 |
| S18 | 0.30 | 0.07 | 1.15 | 0.66 | 2.18 |
| S19 | 0.24 | 0.07 | 0.91 | 0.59 | 1.81 |
| S20 | 0.32 | 0.08 | 1.17 | 0.73 | 2.3 |
| S21 | 0.23 | 0.07 | 0.79 | 0.54 | 1.63 |
| S22 | 0.23 | 0.07 | 0.84 | 0.54 | 1.68 |
| S23 | 0.21 | 0.07 | 0.75 | 0.51 | 1.54 |
| S24 | 0.11 | 0.06 | 0.35 | 0.31 | 0.83 |
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Ai, Q.; Wang, H.; Xiao, C.; Yang, C.; Song, S.; Zhang, M.; Tang, J.; Lei, Y. Simultaneous Determination of Four Fatty Acids in Coix Seeds via Gas Chromatography. ChemEngineering 2025, 9, 98. https://doi.org/10.3390/chemengineering9050098
AMA Style
Ai Q, Wang H, Xiao C, Yang C, Song S, Zhang M, Tang J, Lei Y. Simultaneous Determination of Four Fatty Acids in Coix Seeds via Gas Chromatography. ChemEngineering. 2025; 9(5):98. https://doi.org/10.3390/chemengineering9050098
Chicago/Turabian StyleAi, Qiang, Hui Wang, Chenghong Xiao, Changgui Yang, Shanmin Song, Mingxiang Zhang, Jiandong Tang, and Yang Lei. 2025. "Simultaneous Determination of Four Fatty Acids in Coix Seeds via Gas Chromatography" ChemEngineering 9, no. 5: 98. https://doi.org/10.3390/chemengineering9050098
APA StyleAi, Q., Wang, H., Xiao, C., Yang, C., Song, S., Zhang, M., Tang, J., & Lei, Y. (2025). Simultaneous Determination of Four Fatty Acids in Coix Seeds via Gas Chromatography. ChemEngineering, 9(5), 98. https://doi.org/10.3390/chemengineering9050098
