Whole milk. Determination of milkfat, protein and lactose content. Guidance on the operation of mid-infrared instruments

2015 ◽  
2021 ◽  
Vol 164 ◽  
pp. 106029
Author(s):  
Diego Maciel Gerônimo ◽  
Sheila Catarina de Oliveira ◽  
Frederico Luis Felipe Soares ◽  
Patricio Peralta-Zamora ◽  
Noemi Nagata

2015 ◽  
Vol 87 (19) ◽  
pp. 9580-9583 ◽  
Author(s):  
João Flavio da Silveira Petruci ◽  
Arnaldo Alves Cardoso ◽  
Andreas Wilk ◽  
Vjekoslav Kokoric ◽  
Boris Mizaikoff

Author(s):  
D. G. Revin ◽  
R. S. Hassan ◽  
A. B. Krysa ◽  
K. Kennedy ◽  
A. N. Atkins ◽  
...  

1998 ◽  
Vol 6 (A) ◽  
pp. A163-A170 ◽  
Author(s):  
B. Barabás

The testing and adjusting procedure of near infrared (NIR) spectrophotometers is based on the measurement of some standards and, if necessary, on the adjustment of the constants in the calibration equation. For this work some use few standards, whereas others use 20 or more. This work was aimed to determine the range of error compensation and the minimum number of standards required. The experiments were applied to wheat protein measurement using two scanning spectrophotometers. The errors in the NIR measurements were characterised as bias, skew, error derived from skew ( Eskew) and standard error of difference corrected for bias and skew ( SEDc) parameters and supposed that errors derived from the change in the wavelength or reflectance of the instrument. The confidence intervals of bias and skew, derived from duplicate measurements of various numbers of wheat standards, were used to determine the minimum number of standards required. The range of error compensation was defined with those bias values, where SEDc was smaller, than an acceptable limit. The range of compensation corresponded to a bias value of ± 8 g kg−1 for wheat protein measurements. The detection of error of measurements required 4 wheat standards. The elimination of errors of bias and skew required 9 standards within the above limits. The developed procedure was tested in case of real instrument error. Diminishing a bias from 5.2 g kg−1 to 0.7 g kg−1 and the root mean square difference ( RMSD) to an acceptable level required the use of 9 standards, similar to the model experiment. The simplicity and rapidity (about 10 min) of the procedure enabled the routine test of NIR instruments. The range of error compensation and the number of standards referred to wheat protein. The simple modelling procedure proved also suitable for the determination of these values for other components and under other measuring conditions.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Leonard Nitzsche ◽  
Jens Goldschmidt ◽  
Armin Lambrecht ◽  
Jürgen Wöllenstein

Abstract A dual comb spectrometer is used as gas sensor for the parallel detection of nitrous oxide (N2O) and carbon monoxide (CO). These gases have overlapping absorption features in the mid-infrared (MIR) at a wavelength of 4.6 µm. With a spectra acquisition rate of 10 Hz, concentrations of 50 ppm N2O and 30 ppm CO are monitored with a relative precision of 6 × 10 − 3 6\times {10^{-3}} and 3 × 10 − 3 3\times {10^{-3}} respectively. The limit of detections are 91 ppb for N2O and 50 ppb for CO for an integration time of 25 s. The system exhibits a linear sensitivity from 2 ppm to 100 ppm with coefficients of determination of 0.99998 for N2O and 0.99996 for CO.


1997 ◽  
Vol 80 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Catharina Y W Ang ◽  
Luo Wenhong

Abstract A rapid and sensitive liquid chromatographic (LC) method was developed for the determination of am- picillin residues in raw bovine milk, processed skim milk, and pasteurized, homogenized whole milk with vitamin D. Milk samples were deprote- inized with trichloroacetic acid (TCA) and acetonitrile. After centrifugation, the clear supernatant was reacted with formaldehyde and TCA under heat. The major fluorescent derivative of ampicillin was then determined by reversed-phase LC with fluorescence detection. Average recoveries of ampicillin fortified at 5,10, and 20 ppb (ng/mL) were all >85% with coefficients of variation <10%. Limits of detection ranged from 0.31 to 0.51 ppb and limits of quantitation, from 0.66 to 1.2 ppb. After appropriate validation, this method should be suitable for rapid analysis of milk for ampicillin residues at the tolerance level of 10 ppb.


Data in Brief ◽  
2020 ◽  
Vol 30 ◽  
pp. 105615
Author(s):  
N. Albuquerque ◽  
B. Meehan ◽  
J. Hughes ◽  
A. Surapaneni

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