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Pistachio nuts have high economical and nutritional value, mostly due to their elevated oil content (50%), which is composed mainly of oleic and linoleic fatty acids. Box-Behnken experimental designs were performed to optimize the oil extraction by response surface analysis. The independent variables measured were seed moisture content (SMC), restriction die (RD), screw press speed (PS) and pressing temperature (PT), while the response variables considered were oil recovery (OR), fine solid contents in the oil (FSC), oil remaining in the cake (OC) and parameters related to oil quality (free fatty acid composition (FFAC, mg KOH/g oil), peroxide value (PV, meq O2/kg oil), K232, K270 and pigment contents, mg/kg oil). Given that the chemical quality of pistachio nut oil pressed under different conditions was not affected, the process response was optimized in order to maximize OR under two pressing temperatures. Therefore, at 75 °C, pistachio oil extraction showed a maximum OR (79.61 g/100 g oil) at 8% SMC, 4 mm RD and 20 rpm SP; while, under cold-pressed conditions, the maximum OR (65.97 g/100 g oil) was achieved at 10% SMC, 4mm RD and 20 rpm SP. It is important to highlight that OR values were higher than the results reported previously and the chemical quality parameters from both oils were in the range of Codex standards for virgin (non-refined) oils (FFAC < 0.31 and PV < 0.33). [ABSTRACT FROM AUTHOR]

Abstract Acetaminophen is a very widely used pharmaceutical, consequently it has been detected in the water system. Reliable and robust analytical techniques are thus needed for the detection of acetaminophen, not only for quality control (of pharmaceuticals) and medical control (analysis in biological fluids), but also for environmental matrices. This review gives an overview of analytical methods for acetaminophen using chromatography-mass spectrometry for monitoring aquatic environments, and electrochemical methods for analysis of pharmaceuticals and biological fluids, as well as environmental samples. Other lesser utilized techniques, including spectroscopy and capillary zone electrophoresis, are also discussed. High sensitivity, speed, specificity and reproducibility allow for the utilization of conventional methods for the detection of acetaminophen in routine analysis. However, they are time consuming, expensive and labor intensive. It is envisioned that future research efforts will focus on the development of novel methods and sensor materials to address these limitations. Graphical abstract Image 1 Highlights • The ubiquitous use of acetaminophen may endanger human health and the environment. • A review of analytical techniques for acetaminophen determination is presented. • Advantages and limitations of the analytical methods for acetaminophen are compared. • Traditionally chromatography-mass spectrometry and spectroscopic methods are used. • Recent research also focuses on electrochemical and capillary electrophoresis methods. [ABSTRACT FROM AUTHOR]

Docynia dcne leaf from the genus of Docynia Dcne (including three species of Docynia delavayi, Docynia indica and Docynia longiunguis.) is an important raw material of local ethnic minority tea, ethnomedicines and food supplements in southwestern areas of China. However, D. dcne leaves from these three species are usually used confusingly, which could influence the therapeutic effect of it. A rapid and effective method for the chemical fingerprint and quantitative analysis to evaluate the quality of D. dcne leaves was established. The chemometric methods, including similarity analysis, hierarchical cluster analysis and partial least-squares discrimination analysis, were applied to distinguish 30 batches of D. dcne leaf samples from these three species. The above results could validate each other and successfully group these samples into three categories which were closely related to the species of D. dcne leaves. Moreover, isoquercitrin and phlorizin were screened as the chemical markers to evaluate the quality of D. dcne leaves from different species. And the contents of isoquercitrin and phlorizin varied remarkably in these samples, with ranges of 6.41-38.84 and 95.73-217.76mg/g, respectively. All the results indicated that an integration method of chemical fingerprint couple with chemometrics analysis and quantitative assessment was a powerful and beneficial tool for quality control of D. dcne leaves, and could be applied also for differentiation and quality control of other herbal preparations. [ABSTRACT FROM AUTHOR]

The article focuses on the concept of method transfer which refers to replicating a particular method like ultrahigh-pressure liquid chromatography (UHPLC) in another location other than the same company where it had originated. It discusses how the original laboratory is known as originator laboratory and the other laboratory is known as receiving laboratory. It also talks about how without documentation and product quality control, the method may not get the same results in another location

[Objective] To establish GC-MS fingerprint determination method for volatile oils of FLOS DENDRANTHEMA INDICI, and to provide references for the quality control of FLOS DENDRANTHEMA INDICI. [Methods] Volatile oils were extracted from FLOS DENDRANTHEMA INDICI by steam distiilation. Fingerprint of FLOS DENDRANTHEMA INDICI was detected by GC-MS technology. Chinese herbal fingerprint calculation software was used to calculate the data. Common fingerprint of volatile oils in FLOS DENDRANTHEMA INDICI was established. [Results] Volatile oils in FLOS DENDRANTHEMA INDICI contained 23 characteristic index components; GC-MS fingerprnt was established with these 23 common peaks as the chaacterstic fingerrint information. [Conclusions] This method was precise, stable and repeatable; the established volatile oils fingerprint laid foundation for the quality control of FLOS DENDRANTHEMA INDICI. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the chemical differences between Acori Tatarinowii Rhizoma and Acori Calami Rhizoma using gas chromatography with mass spectrometry and chemometric methods. Quantitative fingerprints were established. A total of 90 volatile compounds were identified and quantified using heuristic evolving latent projection and retention index. An efficient model based on partial least squares-discriminant analysis coupled with variable iterative space shrinkage approach was developed to distinguish Acori Tatarinowii Rhizoma from Acori Calami Rhizoma. The correct rate was 95.83%, and the area under the receiver operating characteristic curve was 100%. Finally, three volatiles, namely, camphor, longicyclene, and -cadinene, were selected as key discrimination factors between Acori Tatarinowii Rhizoma and Acori Calami Rhizoma. The proposed protocol can serve as a valid strategy for quality control and screening of potential bioactive components of herbal medicines. [ABSTRACT FROM AUTHOR]

The article presents a case study of a pharmacopeial method for assay of a drug tablet that fails the repeatability requirement of the system suitability test (SST). An overview of the situation is offered in which different types of SST failures were noticed after using the system in quality control laboratory. The liquid chromatography method troubleshooting to address the problem is mentioned which involved breaking the problem into potential causes and examining it with mental experiments.

Abstract: A quality control (QC) strategy for quantitative and qualitative analysis of “common peaks” in chemical fingerprint was proposed to analyze Yuanhu Zhitong tablet (YZT), using high performance liquid chromatography with diode array detector and tandem mass spectrometry (HPLC-DAD–MS/MS). The chromatographic separation was achieved on an Agilent Eclipse plus C18 column with a gradient elution using a mixture of 0.4‰ ammonium acetate aqueous (pH 6.0 adjusted with glacial acetic acid) and acetonitrile. In chemical fingerprint, 40 peaks were assigned as the “common peaks”. For quantification of “common peaks”, the detection wavelength was set at 254nm, 270nm, 280nm and 345nm, respectively. The method was validated and good results were obtained to simultaneously determine 10 analytes (protopine, jatrorrhizine, coptisine, palmatine, berberine, xanthotoxin, bergapten, tetrahydropalmatine, imperatorin and isoimperatorin). For qualification of “common peaks”, 33 compounds including 10 quantitative analytes were identified or tentatively characterized using LC–MS/MS. These results demonstrated that the present approach may be a powerful and useful tool to tackle the complex quality issue of YZT. [Copyright &y& Elsevier]

A procedure based on liquid chromatography and NMR spectroscopy was developed for controlling the quality of poly(methylphenyl)siloxanes prepared in industry by chemical ring opening of cyclosiloxanes with three (A) and four (A) units. The suggested procedure allows rapid analysis of poly(methylphenyl)siloxanes with determination of the following parameters: residual content of A and A, overall molecular-weight distribution, fractional composition, and molecular characteristics. The results obtained also allow estimating the rheological characteristics of the polymers and the total content of depolymerization products in them. [ABSTRACT FROM AUTHOR]

The fluorescent properties of dissolved organic matter (DOM) are often studied in order to infer DOM characteristics in aquatic environments, including source, quantity, composition, and behavior. While a potentially powerful technique, a single widely implemented standard method for correcting and presenting fluorescence measurements is lacking, leading to difficulties when comparing data collected by different research groups. This paper reports on a large-scale interlaboratory comparison in which natural samples and well-characterized fluorophores were analyzed in 20 laboratories in the U.S., Europe, and Australia. Shortcomings were evident in several areas, including data quality-assurance, the accuracy of spectral correction factors used to correct EEMs, and the treatment of optically dense samples. Data corrected by participants according to individual laboratory procedures were more variable than when corrected under a standard protocol. Wavelength dependency in measurement precision and accuracy were observed within and between instruments, even in corrected data. In an effort to reduce future occurrences of similar problems, algorithms for correcting and calibrating EEMs are described in detail, and MATLAB scripts for implementing the study's protocol are provided. Combined with the recent expansion of spectral fluorescence standards, this approach will serve to increase the intercomparability of DOM fluorescence studies. [ABSTRACT FROM AUTHOR]

Abstract: 5-Chlorovaleroyl chloride (5-CVC) is commonly used as an alkylating agent in the synthesis of pharmaceutical intermediates, active ingredients, as well as other specialty chemicals. It is critical to monitor the impurities present in 5-CVC as they may have a direct impact on the impurity profile and quality of the final product. This paper describes the development and validation of a GC-FID method for the analysis of low level impurities of 5-CVC. This is the first method reported in the literature for the impurity determination of 5-CVC. The results of GC method development, with and without sample derivatization, are presented. The final method uses methanol for derivatization and separates methyl esters of 5-CVC and the key impurities, 4-pentenoyl chloride, 4-chlorovaleroyl chloride, 5-chlorohexanoyl chloride, and 4-methyl-5-chlorovaleroyl chloride. 3-Methoxypyridine was used in the sample solvent to enable the detection of 5-chlorovaleric acid (5-CVA) which is the major degradant of 5-CVC. The method was validated for specificity, linearity, accuracy, precision, sensitivity, and robustness. This simple and robust GC approach may be applicable to impurity analysis of other acid chlorides or acid halides. [Copyright &y& Elsevier]

Measurements of semi-volatile organic chemicals (SVOCs) were compared among 21 laboratories from 7 countries through the analysis of standards, a blind sample, an air extract, and an atmospheric dust sample. Measurement accuracy strongly depended on analytes, laboratories, and types of standards and samples. Intra-laboratory precision was generally good with relative standard deviations (RSDs) of triplicate injections <10% and with median differences of duplicate samples between 2.1 and 22%. Inter-laboratory variability, measured by RSDs of all measurements, was in the range of 2.8–58% in analyzing standards, and 6.9–190% in analyzing blind sample and air extract. Inter-laboratory precision was poorer when samples were subject to cleanup processes, or when SVOCs were quantified at low concentrations. In general, inter-laboratory differences up to a factor of 2 can be expected to analyze atmospheric SVOCs. When comparing air measurements from different laboratories, caution should be exercised if the data variability is less than the inter-laboratory differences. [Copyright &y& Elsevier]

In the production of calcined kaolin, the soluble Al2O3 content is used as a quality control criterion for some speciality applications. The increasing need for automated quality control systems in the industry has brought the necessity of developing techniques that provide (near) real-time data. Based on the understanding that the presence of water in the calcined kaolin detected using infrared spectroscopy can be used as a proxy for the soluble Al2O3 measurement, in this study, a hand-held infrared spectrometer was used to analyse a set of calcined kaolin samples obtained from a production plant. The spectra were used to predict the amount of soluble Al2O3 in the samples by implementing partial least squares regression (PLS-R) and support vector regression (SVR) as multivariate calibration methods. The presence of non-linearities in the dataset and the different types of association between water and the calcined kaolin represented the main challenges for developing a good calibration. In general, SVR showed a better performance than PLS-R, with root mean squared error of the cross-validation (RMSECV) = 0.046 wt % and R 2 = 0.87 for the best-achieved prediction. This accuracy level is adequate for detecting variation trends in the production of calcined kaolin which could be used not only as a quality control strategy, but also for the optimisation of the calcination process. [ABSTRACT FROM AUTHOR]