Dispersive liquid-liquid microextraction based on the solidification of a floating organic droplet for simultaneous analysis of diethofencarb and pyrimethanil in apple pulp and peel

A method for analysis of diethofencarb and pyrimethanil in apple pulp and peel was developed by using dispersive liquid–liquid microextraction based on solidification of a floating organic droplet (DLLME-SFO) and high-performance liquid chromatography with diode-array detection (HPLC–DAD). Acetonitrile was used as the solvent to extract the two fungicides from apple pulp and peel, assisted by microwave irradiation. When the extraction process was finished, the target analytes in the extraction solvent were rapidly transferred from the acetonitrile extract to another extraction solvent (1-undecanol) by using DLLME-SFO. Because of the lower density of 1-undecanol than that of water, the finely dispersed droplets of 1-undecanol collected on the top of aqueous sample and solidified at low temperature. Meanwhile, the tiny particles of apple cooled and precipitated. Recovery was tested for a concentration of 8 μg kg⁻¹. Recovery of diethofencarb and pyrimethanil from apple pulp and peel was in the range 83.5–101.3%. The repeatability of the method, expressed as relative standard deviation, varied between 4.8 and 8.3% (n = 6). Detection limits of the method for apple pulp and peel varied from 1.2–1.6 μg kg⁻¹ for the two fungicides. Compared with conventional sample preparation, the method has the advantage of rapid speed and simple operation, and has high enrichment factors and low consumption of organic solvent.     

High-performance liquid chromatographic determination/identification of oxytetracycline and sulphadimidine in meat and eggs

Summary A rapid method for the simultaneous determination/identification of residual oxytetracycline (OTC) and sulphadimidine (SDD) in meats (beef, pork, chicken) and eggs by high-performance liquid chromatography (HPLC) was developed. The extraction of OTC and SDD was performed using a Sep-Pak^? CN cartridge. The extracts contained OTC/SDD analytes when examined by HPLC using a LiChrospher^? 100 RP-8 end-capped column and a mobile phase of acetonitrile-acetic acid-water (28:4:68, v/v/v) with a photodiode array detector. The average recoveries from spiked samples (0.1 μg g⁻¹ and 1.0 μg g⁻¹) were in excess of 80.2% with coefficients of variation between 1.5 and 5.0%. The limits of detection for OTC and SDD were 0.05 and 0.02 μg g⁻¹, respectively.     

Application of matrix solid-phase dispersion to the determination of amitrole and urazole residues in apples by capillary electrophoresis with electrochemical detection

A new method based on matrix solid-phase dispersion (MSPD) extraction was studied for the extraction of amitrole (3-amino-1,2,4-triazole), and its metabolite urazole (3,5-dihydroxy-1,2,4-triazole), in apple samples. The influence of experimental conditions on the yield of the extraction process and on the efficiency of the cleanup step was evaluated. Determination was carried out by capillary electrophoresis (CE) with electrochemical detection, demonstrating the compatibility between MSPD and CE techniques. The method has been successfully applied to different apple varieties. Recoveries in samples spiked at 1.6 and 1.7 μg g⁻¹ for amitrole and urazole were 88 and 82%, respectively. The limits of detection were 0.4 μg g⁻¹ for both compounds using electrochemical detection.     

HPLC quantification of formaldehyde, as formaldemethone, in plants and plant-like organisms

Summary Formaldehyde, as its dimedone adduct formaldemethone, has been detected and quantified in all the tested species of angiosperms, gymnosperms, pteridophytes, lichens and fungi, as well as in the two species tested of cyanobacteria and the one species of charophyte. Yields ranged from<10μg g⁻¹ to 6940 μg g⁻¹ fresh weight, calculated as formaldemethone (equivalent to <1 μg g⁻¹ to 713 μg g⁻¹ fresh weight, calculated as formaldehyde). An HPLC procedure was used for quantification of formaldemethone. A linear relationship was found between 20 and 2160 μg g⁻¹ and the statistical limit of detection was calculated as 48 μg g⁻¹.     

Simple and rugged SPE method for the determination of tetracycline antibiotics in serum by HPLC using a volatile mobile phase

Summary A simple and rugged SPE method for the determination of tetracycline (TC), minocycline (MC) and demeclocycline (DCC) in porcine serum by high performance liquid chromatography (HPLC) was developed. The spiked serum sample was pretreated with 2% phosphoric acid followed by a simple and rugged solid-phase extraction procedure using the Oasis^TM HLB extraction cartridges. High and reproducible recoveries were obtained even though the cartridges were run dry. The extracted sample analytes were injected onto a Waters SymmetryShield^TM RP₈ column. The mobile phase was a simple volatile solution containing 0.1% TFA, 2% methanol and 7% acetonitrile in Water. The antibiotics were detected at 350 nm. The calibration curves were linear from 2.0 to 25.0 μg mL⁻¹ of TC and MC with DCC as the internal standard at a concentration of 25.0 μg mL⁻¹. For six replicate analyses, the average recoveries of TC and MC from porcine serum sample fortified at the level of 2.5 μg mL⁻¹ were 96.1% with 1.3% RSD and 101% with 0.54% RSD; at level of 0.5 μg mL⁻¹ the average recoveries were 88% with 1.6% RSD and 97.8% with 1.4% RSD.     

Validation of the HS-GC-FID method for the determination of ethanol residue in tablets

This paper describes the validation of a HS-GC-FID method (based on the Pharmacopeia’s method) for the determination of ethanol content in tablets. A general view of the procedure development/optimization process is presented. The main point of this study is the calculation of validation parameters. Selectivity of the method was determined. Linearity (r > 0.997) was observed in the range from 9.0 to 3,040 μg of ethanol per sample (because the mass of the tablets used was around 200 mg, this corresponds to 45–15,200 μg g⁻¹). The method showed good recoveries (average 99.0%), and a relative standard deviation for repeatability and intermediate precision of 4.5% and 5.5% respectively. The limit of detection was calculated to be 3.0 μg of ethanol per sample (15 μg g⁻¹). The uncertainty budget was done according to the "Guide to the Expression of Uncertainty in Measurement" (GUM)[1], and a relative expanded uncertainty was estimated as 4.8%.     

Hapten synthesis and enzyme-linked immunosorbent assay for phosmet residues: assay optimization and investigation of matrix effects from different food samples

In this study, a panel of haptens was synthesized for immunoconjugate preparation, and several haptens for heterologous tracer conjugates were also prepared. A highly sensitive polyclonal antibody against the organophosphorus insecticide phosmet was obtained and competitive direct enzyme-linked immunosorbent assays (cd-ELISA) for this pesticide were developed. In the cd-ELISA, the limit of detection (IC₁₅) was 0.6 μg kg⁻¹ and the sensitivity (IC₅₀) was 20 μg kg⁻¹. The suitability of the ELISA for pesticide quantification in peach, apple, orange juice, and apple juice was also studied. Good accuracy and precision were obtained with mean recoveries between 78% and 102.3% and mean coefficients of variation below 13.63%. Validation of the ELISA was conducted by high-performance liquid chromatography. The correlation between the data obtained using the microwell assay and the high-performance liquid chromatography was good (R ² = 0.9849). The developed immunoassay methods were suitable for the rapid quantitative or qualitative determination of phosmet in food samples.     

Epithermal neutron activation analysis of short-lived nuclides in geological material

The cadmium ratios of 52 short-lived nuclides have been measured. Epithermal neutron irradiation reduces the activities of²⁰F,²⁷Mg,²⁸Al,³⁸Cl,⁴⁹Ca,^46mSc,⁵¹Ti,⁵⁶Mn and⁶⁶Cu by factors of 20–30. The calculated improvements in detection limits for Ga, Br, Rb, Y, Mo, Rh, Pd, Ag, In, Sn, Sb, I, Ba, Nd, Sm, Gd, Dy, Er, Yb, Hf, W, Re, Pt, Au, Th and U are in the range 1–6. Hafnium was measured in USGS rocks: AGV-1 (4.9 μg g⁻¹), G-2 (7.5 μg g⁻¹) and GSP-1 (14.7 μg g⁻¹) and IAEA standards: SOIL-5 (6.3 μg g⁻¹ and SL-1 (4.6 μg g⁻¹). CCRMP reference concentrates PTC and PTM were analysed for rhodium (1.1 and 0.75 μg g⁻¹, respectively) and silver (69 and 5.8 μg g⁻¹, respectively).     

Analysis of captan, folpet, and captafol in apples by dispersive liquid–liquid microextraction combined with gas chromatography

A novel method was developed for the determination of captan, folpet, and captafol in apples by dispersive liquid–liquid microextraction (DLLME) coupled with gas chromatography–electron capture detection (GC–ECD). Some experimental parameters that influence the extraction efficiency, such as the type and volume of the disperser solvents and extraction solvents, extraction time, and addition of salt, were studied and optimized to obtain the best extraction results. Under the optimum conditions, high enrichment factors for the compounds were achieved ranging from 824 to 912. The recoveries of fungicides in apples at spiking levels of 20.0 μg kg⁻¹ and 70.0 μg kg⁻¹ were 93.0–109.5% and 95.4–107.7%, respectively. The relative standard deviations (RSDs) for the apple samples at 30.0 μg kg⁻¹ of each fungicide were in the range from 3.8 to 4.9%. The limits of detection were between 3.0 and 8.0 μg kg⁻¹. The linearity of the method ranged from 10 to 100 μg kg⁻¹ for the three fungicides, with correlation coefficients (r ²) varying from 0.9982 to 0.9997. The obtained results show that the DLLME combined with GC–ECD can satisfy the requirements for the determination of fungicides in apple samples. Figure Dispersive liquid–liquid microextraction (DLLME) coupled with gas chromatography–electron capture detection (GC–ECD) allows satisfactory determination of fungicides in apple samples     

Optimisation of a selective method for the determination of organophosphorous triesters in outdoor particulate samples by pressurised liquid extraction and large-volume injection gas chromatography–positive chemical ionisation–tandem mass spectrometry

A selective analytical method for the determination of nine organophosphate triesters and triphenylphosphine oxide (TPPO) in outdoor particulate matter is presented. It involves a fully automated pressurised liquid extraction (PLE) step, integrating an alumina clean-up process, and subsequent determination by large-volume injection gas chromatography–positive chemical ionisation–tandem mass spectrometry (LVI-GC–PCI–MS/MS). The extraction variables (solvent, amount of adsorbent, temperature, time and number of cycles) were optimised using a multicriteria strategy which implements a desirability function that maximises both extraction and clean-up efficiencies while searching for the best-compromise PLE conditions. The final method affords quantification limits of between 0.01 and 0.3 μg g⁻¹ and recoveries of >80%, with the exceptions of the most polar analytes, TCEP and TPPO (~65%) for both urban dust and PM10 samples. Moreover, the method permitted the levels of these compounds in dust deposited outdoors (between LOD and 0.5 μg g⁻¹ for TEHP) and PM10 samples (between LOD and 2.4 μg m⁻³ for TiBP) to be measured and reported for the first time. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Potential of microcolumn liquid chromatography and capillary electrophoresis with flame photometric detection for determination of polar phosphorus-containing pesticides

Summary The potential of microcolumn liquid chromatography (μlC) and capillary electrophoresis (CE) with on-line, flame photometric detection (FPD) in the P-selective mode has been studied for determination of polar P-containing pesticides, glyphosate and its main metabolite, aminomethylphosphonic acid (AMPA), ethephon, fosetyl-aluminium and acephate. Acephate was determined by reversed-phase μLLC-FPD using large-volume injections with peak compression, the other compounds were determined by μLC-FPD and CE-FPD using simple, large-volume injection procedures to obtain limits of detection of 7.5-500 ng·mL⁻¹ and 1.0 μ·mL⁻¹, respectively. The methods showed acceptable repeatability and robustness and were successfully applied for rapid and selective determination of pesticides in fruit, vegetable and water samples.     

Determination of Antioxidants and Preservatives in Cosmetics by SPME Combined with GC–MS

A rapid and simple procedure for the determination of antioxidants and preservatives in cosmetics has been developed utilizing solid-phase microextraction combined with GC–MS. A silica fiber coated with polyacrylate provided the highest extraction efficiency. Detection limits in the range from 0.4 to 8.5 ng mL⁻¹ were obtained. Linearity is over a wide range from 1 to 2,000 ng mL⁻¹ with a relative standard deviation under 16%. Cosmetic from a local supermarket were analysed for antioxidants and preservatives to demonstrate the effectiveness of the proposed method. The concentration of antioxidants and preservatives determined was 20–1,218 μg g⁻¹ for methylparaben and 5–3,779 μg g⁻¹ for propylparaben.     

Determination of water-soluble and insoluble (dilute-HCl-extractable) fractions of Cd,Pb and Cu in Antarctic aerosol by square wave anodic stripping voltammetry: distribution and summer seasonal evolution at Terra Nova Bay (Victoria Land)

Eight PM10 aerosol samples were collected in the vicinity of the “Mario Zucchelli” Italian Antarctic Station (formerly Terra Nova Bay Station) during the 2000–2001 austral summer using a high-volume sampler and precleaned cellulose filters. The aerosol mass was determined by differential weighing of filters carried out in a clean chemistry laboratory under controlled temperature and humidity. A two-step sequential extraction procedure was used to separate the water-soluble and the insoluble (dilute-HCl-extractable) fractions. Cd, Pb and Cu were determined in the two fractions using an ultrasensitive square wave anodic stripping voltammetric (SWASV) procedure set up for and applied to aerosol samples for the first time. Total extractable metals showed maxima at midsummer for Cd and Pb and a less clear trend for Cu. In particular, particulate metal concentrations ranged as follows: Cd 0.84–9.2 μg g⁻¹ (average 4.7 μg g⁻¹), Pb 13.2–81 μg g⁻¹ (average 33 μg g⁻¹), Cu 126–628 μg g⁻¹ (average 378 μg g⁻¹). In terms of atmospheric concentration, the values were: Cd 0.55–6.3 pg m⁻³ (average 3.4 pg m⁻³), Pb 8.7–48 pg m⁻³ (average 24 pg m⁻³), Cu 75–365 pg m⁻³ (average 266 pg m⁻³). At the beginning of the season the three metals appear widely distributed in the insoluble (HCl-extractable) fraction (higher proportions for Cd and Pb, 90–100%, and lower for Cu, 70–90%) with maxima in the second half of December. The soluble fraction then increases, and at the end of the season Cd and Pb are approximately equidistributed between the two fractions, while for Cu the soluble fraction reaches its maximum level of 36%. Practically negligible contributions are estimated for crustal and sea-spray sources. Low but significant volcanic contributions are estimated for Cd and Pb (∼10% and ∼5%, respectively), while there is an evident although not quantified marine biogenic source, at least for Cd. The estimated natural contributions (possibly including the marine biogenic source) cannot account for the high fractions of the metal contents, particularly for Pb and Cu, and this suggests that pollution from long-range transport is the dominant source. Figure Aerosol sampling in Antarctica     

Matrix solid phase dispersion–Soxhlet simultaneous extraction clean-up for determination of organochlorine pesticide residues in tobacco

A novel method combining matrix solid phase dispersion (MSPD) with Soxhlet simultaneous extraction clean-up (SSEC) was developed. Being a single-step extraction and clean-up procedure, it could be used instead of multistep solvent extraction and Florisol column clean-up. It not only reduces sample contamination during the procedure, but it also decreases the amount of organic solvent needed. The retention times of standards were used to qualitatively assess the method, and the external standard method was used to quantitatively assess it. Residues of organochlorine pesticides (OCP) in tobaccos were determined by gas chromatography–electron capture detection (GC–ECD), and their identities were confirmed by the standard addition method (SAM). The performance of the method was evaluated and validated: the detection limit was 0.01–0.02 μg g⁻¹, relative standard deviations were 5–26%, and recoveries were 72–99% at fortification levels of 0.10, 1.00 and 10.0 μg g⁻¹. The analytical characteristics of MSPD–SSEC compared very favorably with the results from the classical multistep solvent extraction and Florisol column clean-up method.     

Residue analysis of four diacylhydrazine insecticides in fruits and vegetables by Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method using ultra-performance liquid chromatography coupled to tandem mass spectrometry

The new analytical method using Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) procedure for simultaneous determination of diacylhydrazine insecticide residues in fruits and vegetables was developed using ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). The four insecticides (tebufenozide, methoxfenozide, chromafenozide, and halofenozide) were extracted from six fruit and vegetable matrices using acetonitrile and subsequently cleaned up using primary secondary amine (PSA) or octadecylsilane (C18) as sorbent prior to UPLC-MS/MS analysis. The determination of the target compounds was achieved in less than 3.0 min using an electrospray ionization source in positive mode (ESI+) for tebufenozide, methoxfenozide, and halofenozide and in negative mode (ESI−) for chromafenozide. The limits of detection were below 0.6 μg kg⁻¹, while the limit of quantification did not exceed 2 μg kg⁻¹ in different matrices. The QuEChERS procedure by using two sorbents (PSA and C18) and the matrix-matched standards gave satisfactory recoveries and relative standard deviation (RSD) values in different matrices at four spiked levels (0.01, 0.05, 0.1, and 1 mg kg⁻¹). The overall average recoveries for this method in apple, grape, cucumber, tomato, cabbage, and spinach at four levels ranged from 74.2% to 112.5% with RSDs in the range of 1.4–13.8% (n = 5) for all analytes. This study provides a theoretical basis for China to draw up maximum residue limits and analytical method for diacylhydrazine insecticide in vegetables and fruits.     

Organosilica composite for preconcentration of phenolic compounds from aqueous solutions

A new adsorbent is proposed for the solid-phase extraction of phenol and 1-naphthol from polluted water. The adsorbent (TX-SiO₂) is an organosilica composite made from a bifunctional immobilized layer comprising a major fraction (91%) of hydrophilic diol groups and minor fraction (9%) of the amphiphilic long-chain nonionic surfactant Triton X-100 (polyoxyethylated isooctylphenol) (TX). Under static conditions phenol was quantitatively extracted onto TX-SiO₂ in the form of a 4-nitrophenylazophenolate ion associate with cetyltrimethylammonium bromide. The capacity of TX-SiO₂ for phenol is 2.4 mg g⁻¹ with distribution coefficients up to 3.4 × 10⁴ mL g⁻¹; corresponding data for 1-naphthol are 1.5 mg g⁻¹ and 3 × 10³ mL g⁻¹. The distribution coefficient does not change significantly for solution volumes of 0.025–0.5 L and adsorbent mass less than 0.03 g; 1–90 μg analyte can be easily eluted by 1–3 mL acetonitrile with an overall recovery of 98.2% and 78.3% for phenol and 1-naphthol, respectively. Linear correlation between acetonitrile solution absorbance (A ₅₄₀) and phenol concentration (C) in water was found according to the equation A ₅₄₀ = (6 ± 1) × 10⁻² + (0.9 ± 0.1)C (μmol L⁻¹) with a detection range from 1 × 10⁻⁸ mol L⁻¹ (0.9 μL g⁻¹) to 2 × 10⁻⁷ mol L⁻¹ (19 μL g⁻¹), a limit of quantification of 1 μL g⁻¹ (preconcentration factor 125), correlation coefficient of 0.936, and relative standard deviation of 2.5%. A solid-phase colorimetric method was developed for quantitative determination of 1-naphthol on adsorbent phase using scanner technology and RGB numerical analysis. The detection limit of 1-naphthol with this method is 6 μL g⁻¹ while the quantification limit is 20 μL g⁻¹. A test system was developed for naked eye monitoring of 1-naphthol impurities in water. The proposed test kit allows one to observe changes in the adsorbent color when 1-naphthol concentration in water is 0.08–3.2 mL g⁻¹.     

GC determination of nicotine in subcutaneous adipose tissue obtained by minimal trauma tissue biopsy

Summary Nicotine has been analyzed by gas chromatography nitrogen-phosphorus detection in tissue samples obtained by repeated minimal trauma tissue biopsies from human subcutaneous adipose tissue. For sample preparation, a single extraction step of the tissue samples with chloroform was performed at 30–45°C. Calibration curves generated with spiked porcine subcutaneous adipose tissue were linear over a concentration range from 0.20 to 100 μg g⁻¹, therefore, the limit of quantification was fixed at 0.20 μg g⁻¹. The limit of detection was found to be 0.05 μg g⁻¹ adipose tissue. The recovery of nicotinespiked porcine subcutaneous adipose tissue by chloroform extraction was 100±8%. The performance of the assay was not affected by the complex lipid matrix. The method was employed for analysis in a clinical study on nicotine penetration from a transdermal delivery system through the skin of moderate smokers. Presented at Balaton Symposium on High Performance Separation Methods, Siófok, Hungary, September 1–3, 1999.     

Simplified liquid-chromatographic determination of residues of tetracycline antibiotics in eggs

Summary A high-performance liquid chromatographic (HPLC) procedure is described for the identification and quantification of residues of tetracycline antibiotics (TCA) (oxytetracycline, tetracycline, chlortetracycline, and doxycycline), in eggs. Spiked and blank samples were prepared by homogenization with 1∶1 (v/v) acetonitrile-mixed Mcllvaine buffer and EDTA solution (pH 4.0) then centrifugal ultrafiltration. HPLC was performed on a reversed-phase column with acetonitrile-5% (v/v) aqueous acetic acid, 35∶65 (v/v), as mobile phase and photo-diode array detection. Average recoveries (each drug spiked at 0.1, 0.2, 0.3, 0.5 and 1.0 μg g⁻¹) were >-77% with standard deviations (SD) between 1.5 and 3.5%. The inter-assay variabilities and theirSD were <3.4% and <0.7%, respectively, and intra-assay variability was between 2.0 and 3.9%. The limits of quantitation (LOQ) were 0.064 0.087, 0.121, and 0.131 μg g⁻¹ for OTC, TC, CTC, and DC, respectively. The total time required for the analysis of one sample was less than 30 min.     

Simultaneous Determination of Baicalin, Baicalein, Wogonin, Oxysophocarpine, Oxymatrine and Matrine in the Chinese Herbal Preparation of Sanwu-Huangqin-Tang by Ion-Paired HPLC

A sensitive and reliable ion-paired high-performance liquid chromatographic method has been established for the simultaneous quantification of six major active ingredients, namely baicalin, baicalein, wogonin, oxysophocarpine, oxymatrine and matrine in the Chinese herbal preparation, Sanwu-Huangqin-Tang. HPLC analyses were performed on a Phenomenex luna C₁₈ column with mobile phase of methanol–acetonitrile–aqueous phosphoric acid at a flow rate of 0.9 mL min⁻¹. The complete separation was achieved within 35 min for the six target constituents. A good linear regression relationship between peak-areas and concentrations was obtained over the range of 12.10–242.0 μg*mL⁻¹ for baicalin, 5.05–101.0 μg*mL⁻¹ for baicalein, 0.95–19.0 μg*mL⁻¹ for wogonin, 2.75–55.0 μg*mL⁻¹ for oxysophocarpin, 2.75–55.0 μg*mL⁻¹ for oxymatrine and 4.90–98.0 μg*mL⁻¹ for matrine, respectively. The repeatability was evaluated by intra- and inter-day assays with relative standard deviation (RSD) being less than 5.1%. The recoveries, measured at three concentration levels, varied from 93.8 to 102.1%. The assay was successfully applied for determination of six bioactive compounds in Sanwu-Huangqin-Tang. The interaction of chemical constituents was observed when the herbs were used in compatibility. The results indicated that the developed assay method was rapid, accurate and could be readily utilized as a quality control method for Sanwu-Huangqin-Tang.     

LC Determination of Four Isoflavone Aglycones in Red Clover (Trifolium pratense L.)

Red clover (Trifolium pratense L.) is an important forage plant that contains the isoflavones daidzein, genistein, formononetin, and biochanin A. These compounds have been studied lately due to their human health benefits. The aim of this study was to develop and validate an HPLC method with simplified sample preparation to quantify daidzein, genistein, formononetin and biochanin A simultaneously in red clover leaves. The validation showed that the method is specific, accurate, precise and robust, not to mention that the sample preparation is easier and faster than those described earlier. The response was linear over a range of 0.01–0.2 μg mL⁻¹ for daidzein, 0.05–0.5 μg mL⁻¹ for genistein, 4–40 μg mL⁻¹ for formononetin and 2–20 μg mL⁻¹ for biochanin A. The range of recoveries was 85.6–101.0%. The RSD for intra- and inter-day precision were <2.54 and <7.22%, respectively. Five populations of red clover, from the National Plant Germplasm System-USDA were analyzed and the content of daidzein, genistein, formononetin and biochanin A ranged from 7.87–91.31, 51.60–131.30, 6568.33–23461.82, to 2499.55–10337.33 μg g⁻¹ of dried material, respectively.