Residual level of dimethachlon in rice-paddy field system and cooked rice determined by gas chromatography with electron capture detector

2018 ◽  
Vol 32 (7) ◽  
pp. e4226 ◽  
Author(s):  
Caiyuan Sun ◽  
Lingrong Zeng ◽  
Jin Xu ◽  
Lei Zhong ◽  
Xinwen Han ◽  
...  
Author(s):  
Haiming Tang ◽  
Chao Li ◽  
Lihong Shi ◽  
Li Wen ◽  
Kaikai Cheng ◽  
...  

Abstract Soil organic matter (SOM) and its fractions play an important role in maintaining or improving soil quality and soil fertility. Therefore, the effects of a 34-year long-term fertilizer regime on six functional SOM fractions under a double-cropping rice paddy field of southern China were studied in the current paper. The field experiment included four different fertilizer treatments: chemical fertilizer alone (MF), rice straw residue and chemical fertilizer (RF), 30% organic manure and 70% chemical fertilizer (OM) and without fertilizer input as control (CK). The results showed that coarse unprotected particulate organic matter (cPOM), biochemically, physically–biochemically and chemically protected silt-sized fractions (NH-dSilt, NH-μSilt and H-dSilt) were the main carbon (C) storage fractions under long-term fertilization conditions, accounting for 16.7–26.5, 31.1–35.6, 16.2–17.3 and 7.5–8.2% of the total soil organic carbon (SOC) content in paddy soil, respectively. Compared with control, OM treatment increased the SOC content in the cPOM, fine unprotected POM fraction, pure physically protected fraction and physico-chemically protected fractions by 58.9, 106.7, 117.6 and 28.3%, respectively. The largest proportion of SOC to total SOC in the different fractions was biochemically protected, followed by chemically and unprotected, and physically protected were the smallest. These results suggested that a physical protection mechanism plays an important role in stabilizing C of paddy soil. In summary, the results showed that higher functional SOM fractions and physical protection mechanism play an important role in SOM cycling in terms of C sequestration under the double-cropping rice paddy field.


1971 ◽  
Vol 54 (3) ◽  
pp. 711-712
Author(s):  
Martha Fuzesi

Abstract A gas chromatographic method is described for the quantitative determination of N-butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-tolindine and α,α,α-trifluoro-2,6-dinitro-N,N-dipropyI-p-toluidine herbicides in formulations. The sample is extracted with benzene, and equal amounts of sample and reference solution in the same concentration range are analyzed by gas chromatography, using an electron capture detector and an SE-30/Diatoport S column. The method has been applied successfully to laboratory-prepared and commercial samples.


2012 ◽  
Vol 134 (4) ◽  
pp. 2424-2429 ◽  
Author(s):  
Shengbing Yu ◽  
Binghui Zhu ◽  
Fen Lv ◽  
Shaoxiao Li ◽  
Weixiong Huang

2012 ◽  
Vol 57 (1) ◽  
Author(s):  
UMI KALTHOM AHMAD ◽  
NOOR HIDAYAT ABU BAKAR ◽  
SHAIKH ABDUL ADZIZ SHAIKH ABDULLAH

The occurrence of crimes involving high explosives in Malaysia in recent years has warrant the need for the analysis of high explosives in post blast samples, particularly residues that could be found on hairs of victims. This study reports on the detection of post blast residues of C4 explosives on human head hairs. Prior to a simulated explosion, a bundle of hair (200 strands) was tightly bound to a metal hook at each point of several pre–determined distances from the bomb seat. Hair samples containing post blast residues were extracted by ultrasonication using acetonitrile. Two analytes of interest, cyclotrimethylenetrinitramine (RDX) and pentaerythritol tetranitrate (PETN) were successfully separated using gas chromatography with electron capture detector (GC–ECD) on an HP5–MS capillary column. It was found that the amount of explosive residues decreased with increasing distance from the point of blast. At the nearest specified distance of 2.5m, the amount of PETN residues deposited on hair was much less compared to that of RDX residues.


2018 ◽  
pp. 231-244 ◽  
Author(s):  
Kazuyuki Yagi ◽  
Katsumi Kumagai ◽  
Haruo Tsuruta ◽  
Katsuyuki Minami

2016 ◽  
Vol 46 (1) ◽  
pp. 70-79 ◽  
Author(s):  
Lak Jung Choe ◽  
Kwang Jin Cho ◽  
Min Su Han ◽  
Min Kyeong Kim ◽  
Soon Kun Choi ◽  
...  

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